The above instruments use alternative power and thus this thread for general information..
Alternative power generators produce electricity from renewable energy sources such as wind, flowing water, solar energy and biomass.
They are used for residential power, portable power, lighting, and communications applications. Alternative power generators use green energy from renewable sources. They cause less environmental degradation and pollution than products that use fossil fuels such as coal, diesel, and gasoline. Alternative power generators are used with solar power panels, solar water pumps, and complete solar power systems. They are also used with wind turbines, micro hydro generators, and complete wind power systems. Biomass includes wood and wood waste, fast-growing trees and plants, and agricultural crops and wastes. Alternative power generators that use other sources of green energy are also available.
Wind power systems convert the kinetic energy from wind into mechanical energy. When used with a wind power generator, the rotation of the wind turbine’s blades turns a shaft to produce electricity. Specifications for wind power generators include blade material, rotor diameter, unit weight, start-up wind speed, voltage, wattage, and mounting style. Wind generator blades are often made of carbon-reinforced thermoplastic, injection-molded polycarbonate, or fiberglass. Rotor diameter is measured in inches (in) or meters (m). Weight is specified in pounds (lbs) or kilograms (kg). Product specifications for wind power generators include rated output, rated wind speed, rated rotation, cut-in speed, percent rated output, airfoil type, lateral type, and governor speed. Some wind-based alternative power generators are designed for rooftop mounting. Others require a tower and can be used in conjunction with photovoltaic modules (PV).
Hydropower systems convert water pressure into mechanical energy. When used with a water power generator, the movement of the turbine’s runners or propellers turns a shaft to produce electricity. There are three basic types of hydro turbines: impulse, reaction, and submersible propeller. All produce clean energy or green energy - power from renewable resources. Specifications for water power generators include volts, watts, phase, per minute (RPM), length, height, and weight. Micro hydro generators are alternative power generators that produce electricity from fast-running streams without turbines, dams, or pipes. They are designed or residential use and can withstand cold-weather environments.
Solar power generators are alternative power generators that convert light from the sun into electricity. There are many different types of photovoltaic (PV) and solar power supplies. Examples include solar batteries, solar battery chargers, and solar panels. A solar battery is a sealed, maintenance-free device. A solar battery charger can be used to power devices such as radio receivers, lighting, and radio modems. A solar panel is a device that converts energy from the sun into usable forms, either by absorbing the sun’s heat directly, or by converting its light into electricity. A photovoltaic system or PV system may include a battery backup or uninterruptible power supply (UPS) that can operate selected circuits for hours or even days. PV and solar power supplies include products such as solar arrays and are used with alternative power generators.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Experienced Instrumentation Engineer shares technical information and tips to be used by Instrumentation Professionals, Students and Educators.
Tuesday, January 4, 2011
Application Notes on Hardness Testers.
Hardness testers measure a materials' resistance to indentation. Hardness is a characteristic of a material, not a fundamental physical property. It is defined as the resistance to indentation, and it is determined by measuring the permanent depth or projected area of the indentation. More simply put, when using a fixed force (load) and a given indenter, the smaller the indentation, the harder the material. Indentation hardness value is obtained by measuring the depth or the area of the indentation using one of many different test methods. Hardness testers use one of several types of scales for determining the hardness of a sample. These include Brinell, dynamic rebound, coating or nanoindentation, Rockwell, Vickers and Knoop and ultrasonic. Methods include macro, micro and superficial testing.
Brinell hardness testers are widely used on castings and forgings. This method applies a predetermined test force to a carbide ball of fixed diameter that is held for a predetermined time and then removed. The diameter of the indentation width is measured twice - usually at right angles to each other and averaged. A formula or chart is then used to convert the averaged measurements to a Brinell hardness number. Test forces usually range from 500 to 3000 kilograms (occasionally down to 1kg in less frequently used tests).
In dynamic rebound or impact hardness testers, a hammer or diamond tipped probe is dropped onto a sample and the rebound height or velocity change is measured and converted into a hardness reading. The rebound height increases with increasing hardness. These tests are less destructive than conventional static indentation tests and applied where even a small indent on a surface cannot be tolerated; e.g., forged rolls for printing.
Coating hardness testers use indentation, scratching or rubbing tests to evaluate the hardness or wear resistance of thin films of paint, sealants, adhesives, vapor deposits, CVD/PVD deposits or plated layers.
The Rockwell test method is defined in ASTM E-18 and is the most commonly used hardness tester operation method since it is generally easier to perform and more accurate than other types of hardness testing. Rockwell testers can be used on all metals except in conditions where the test metal structure or surface conditions would introduce too much variation, where the indentations would be too large for the application or where the sample size or shape prohibits its use. The Rockwell tester method measures the permanent depth of indentation produced by a force on an indenter.
Vickers and Knoop hardness testers can be used for Micro and Macro hardness testing. Typically loads are very light, ranging from a few grams to one or several kilograms, although "Macro" Vickers loads can range up to 30 kg or more. The Microhardness testing operation according to ASTM E-384 specifies a range of loads between 1 to 1000 g. There are two types of indenters; a square base pyramid shaped diamond for testing in a Vickers tester and a narrow rhombus shaped indenter for a Knoop tester. The Micro-hardness methods are used to test on metals, ceramics, and composites - almost any type of material.
In ultrasonic hardness testers, a probe tipped with an indenter is piezoelectrically resonated at an ultrasonic frequency. The probe is held against the sample with a spring and a small indentation is made. The frequency of the probe changes in proportion to the contact area of the indentation. The tester measures the frequency change, then calculates and displays the equivalent hardness value.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Brinell hardness testers are widely used on castings and forgings. This method applies a predetermined test force to a carbide ball of fixed diameter that is held for a predetermined time and then removed. The diameter of the indentation width is measured twice - usually at right angles to each other and averaged. A formula or chart is then used to convert the averaged measurements to a Brinell hardness number. Test forces usually range from 500 to 3000 kilograms (occasionally down to 1kg in less frequently used tests).
In dynamic rebound or impact hardness testers, a hammer or diamond tipped probe is dropped onto a sample and the rebound height or velocity change is measured and converted into a hardness reading. The rebound height increases with increasing hardness. These tests are less destructive than conventional static indentation tests and applied where even a small indent on a surface cannot be tolerated; e.g., forged rolls for printing.
Coating hardness testers use indentation, scratching or rubbing tests to evaluate the hardness or wear resistance of thin films of paint, sealants, adhesives, vapor deposits, CVD/PVD deposits or plated layers.
The Rockwell test method is defined in ASTM E-18 and is the most commonly used hardness tester operation method since it is generally easier to perform and more accurate than other types of hardness testing. Rockwell testers can be used on all metals except in conditions where the test metal structure or surface conditions would introduce too much variation, where the indentations would be too large for the application or where the sample size or shape prohibits its use. The Rockwell tester method measures the permanent depth of indentation produced by a force on an indenter.
Vickers and Knoop hardness testers can be used for Micro and Macro hardness testing. Typically loads are very light, ranging from a few grams to one or several kilograms, although "Macro" Vickers loads can range up to 30 kg or more. The Microhardness testing operation according to ASTM E-384 specifies a range of loads between 1 to 1000 g. There are two types of indenters; a square base pyramid shaped diamond for testing in a Vickers tester and a narrow rhombus shaped indenter for a Knoop tester. The Micro-hardness methods are used to test on metals, ceramics, and composites - almost any type of material.
In ultrasonic hardness testers, a probe tipped with an indenter is piezoelectrically resonated at an ultrasonic frequency. The probe is held against the sample with a spring and a small indentation is made. The frequency of the probe changes in proportion to the contact area of the indentation. The tester measures the frequency change, then calculates and displays the equivalent hardness value.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes On Thermal Imagers
Invaluable for moisture problems and mould problems!
Moisture in building materials can destroy the structural integrity and nurture mould and insect infestation. Infrared cameras can instantly image entire rooms, inspect hard-to-reach places, reveal wet conditions behind surfaces at the source, and then monitor when the area is completely dry.
Perfect for finding hot spots!
For mechanical equipment, nearly everything gets hot before it fails - making infrared cameras extremely cost-effective and valuable diagnostic tools in many diverse applications.
Features:
• High accuracy and thermal sensitivity helps you find problems faster and easier - critical for condition monitoring of thermally sensitive targets
• Extremely lightweight
• Easy-to-use - Fully automatic design makes it easy-to-use and perfect for general purpose use
• Focus free lens - For convenient viewing
• High Resolution
• Rugged design with easy grip handle construction
• Measurement Modes - Spot (center), Area (Min/Max), and Isotherm (above/below) display measurement modes
• Long Battery Life
• Large Memory Storage
How can infrared cameras assist you?
Infrared cameras meet the demands of building diagnostics. They feature immediate high-resolution thermal imagery, which reveals potential structural and moisture issues, energy efficiency and even rodents or pests. Use an infrared camera to find:
• Moisture
• Missing or defective insulation
• Structural shortcomings
• HVAC problem areas
• Sourced of heating/cooling losses
• Plumbing blockages
• Roof leaks
• Electrical issues
• Rodents and other pests
• And much more!
Who could use Thermal Imaging Cameras?
• Building Inspectors
• Electricians
• General Contractors
• Home Efficiency Consultants
• Plant Maintenance Professionals
• HVAC/R Contractors
• Mold Remediation Professionals
• Plumbers
Preventive Maintenance
Thermal imaging is a valuable tool in preventive maintenance of electrical, mechanical and structural systems, able to help detect problems, prevent unscheduled downtime, guide needed corrective action and increase plant safety.
Utility Market
In the utility industry, failure is not an option. That’s why infrared thermal imaging has become a key tool for predictive maintenance programs for utility firms everywhere.
Energy Audits
Energy costs are increasing at a substantially alarming rate. Missing or low quality insulation, inadequate Heating, Ventilation, and Air Conditioning (HVAC) systems, poor air flow - all are typical problems that cause homes to waste energy.
Applications:
• Detect hidden problems, make quick damage assessments
• Check for overheating of electrical panels and transformers
• Avoid electrical failures
• Identify faults in heating and cooling systems
• Find problems with motors, fans and bearings
• Generate reports, analyse and document your findings.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Moisture in building materials can destroy the structural integrity and nurture mould and insect infestation. Infrared cameras can instantly image entire rooms, inspect hard-to-reach places, reveal wet conditions behind surfaces at the source, and then monitor when the area is completely dry.
Perfect for finding hot spots!
For mechanical equipment, nearly everything gets hot before it fails - making infrared cameras extremely cost-effective and valuable diagnostic tools in many diverse applications.
Features:
• High accuracy and thermal sensitivity helps you find problems faster and easier - critical for condition monitoring of thermally sensitive targets
• Extremely lightweight
• Easy-to-use - Fully automatic design makes it easy-to-use and perfect for general purpose use
• Focus free lens - For convenient viewing
• High Resolution
• Rugged design with easy grip handle construction
• Measurement Modes - Spot (center), Area (Min/Max), and Isotherm (above/below) display measurement modes
• Long Battery Life
• Large Memory Storage
How can infrared cameras assist you?
Infrared cameras meet the demands of building diagnostics. They feature immediate high-resolution thermal imagery, which reveals potential structural and moisture issues, energy efficiency and even rodents or pests. Use an infrared camera to find:
• Moisture
• Missing or defective insulation
• Structural shortcomings
• HVAC problem areas
• Sourced of heating/cooling losses
• Plumbing blockages
• Roof leaks
• Electrical issues
• Rodents and other pests
• And much more!
Who could use Thermal Imaging Cameras?
• Building Inspectors
• Electricians
• General Contractors
• Home Efficiency Consultants
• Plant Maintenance Professionals
• HVAC/R Contractors
• Mold Remediation Professionals
• Plumbers
Preventive Maintenance
Thermal imaging is a valuable tool in preventive maintenance of electrical, mechanical and structural systems, able to help detect problems, prevent unscheduled downtime, guide needed corrective action and increase plant safety.
Utility Market
In the utility industry, failure is not an option. That’s why infrared thermal imaging has become a key tool for predictive maintenance programs for utility firms everywhere.
Energy Audits
Energy costs are increasing at a substantially alarming rate. Missing or low quality insulation, inadequate Heating, Ventilation, and Air Conditioning (HVAC) systems, poor air flow - all are typical problems that cause homes to waste energy.
Applications:
• Detect hidden problems, make quick damage assessments
• Check for overheating of electrical panels and transformers
• Avoid electrical failures
• Identify faults in heating and cooling systems
• Find problems with motors, fans and bearings
• Generate reports, analyse and document your findings.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Power Meters or Watt Meters.
Power meters are used for high-accuracy measurements of power over a wide-frequency bandwidth, and from both AC and DC circuits. Measurements can be obtained for single-phase and three-phase AC systems. Some power meters can measure true RMS power. Root mean square (RMS) is the value obtained when the maximum voltage or current is divided by the square root of two. Power meters can be used for the measurement of power in various conditions, including half-wave and full-wave rectified waveforms, mixed AC/DC waveforms, and distorted waveforms.
Performance specifications for power meters include power range, number of channels, sampling rate, and the type of power to measure. There are four measurement types: active power, apparent power, reactive power and power factor. Active power is the time rate of transferring or transforming energy. The electrical power at a single terminal-pair is the product of the voltage and current. Apparent power is the product of the RMS values of voltage and current. Reactive power is the product of the RMS value of the voltage and the RMS value of the quadrature component of the current. Finally, power factor or quality factor is the ratio of active power to apparent power.
Phase angle parameters are also important product specifications for power meters. The phase angle is the angle, in degrees, between the current waveform and the voltage waveform. A leading phase angle means that the current is ahead of the voltage and the load is capacitive. If the current lags the voltage, then the phase angle is lagging and the load is inductive.
Power meters are available with a variety of features. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated (Wh and Ah). Scaling functions allow the potential transformer and current transformer ratio to be preset. Power meters can also support a wide range of current sensors used for evaluating inverter driven equipment and high frequency lighting equipment. Automatic range switching means that when the measured value falls out of the rated range, the meter switches automatically to the appropriate unit for the range being measured. Harmonic analysis is phase measurement between three-phase inputs and measurement of active, reactive or apparent power of the fundamental wave. Other, more general features for power meters include filtering, data logging, event triggering, and application software.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Performance specifications for power meters include power range, number of channels, sampling rate, and the type of power to measure. There are four measurement types: active power, apparent power, reactive power and power factor. Active power is the time rate of transferring or transforming energy. The electrical power at a single terminal-pair is the product of the voltage and current. Apparent power is the product of the RMS values of voltage and current. Reactive power is the product of the RMS value of the voltage and the RMS value of the quadrature component of the current. Finally, power factor or quality factor is the ratio of active power to apparent power.
Phase angle parameters are also important product specifications for power meters. The phase angle is the angle, in degrees, between the current waveform and the voltage waveform. A leading phase angle means that the current is ahead of the voltage and the load is capacitive. If the current lags the voltage, then the phase angle is lagging and the load is inductive.
Power meters are available with a variety of features. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated (Wh and Ah). Scaling functions allow the potential transformer and current transformer ratio to be preset. Power meters can also support a wide range of current sensors used for evaluating inverter driven equipment and high frequency lighting equipment. Automatic range switching means that when the measured value falls out of the rated range, the meter switches automatically to the appropriate unit for the range being measured. Harmonic analysis is phase measurement between three-phase inputs and measurement of active, reactive or apparent power of the fundamental wave. Other, more general features for power meters include filtering, data logging, event triggering, and application software.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on SWR Meters.
SWR meters are used to measure the standing wave ratio (SWR) in radio equipment. They are sometimes called VSWR meters, a reference to voltage standing wave ratio (VSWR). SWR is the ratio of the amplitude of a partial standing-wave at maximum amplitude to the amplitude at an adjacent node. In telecommunications applications, standing wave ratio is a measure of the quality of the match between the antenna and the receiving system. VSWR is the ratio of the maximum voltage to the minimum voltage on an electrical transmission line. In other words, it is a measure of the impedance mismatch between a transmission line and load.
Selecting SWR meters and VSWR meters requires an analysis of form factors. Benchtop instruments are designed to sit atop a bench or table, typically in a laboratory setting. Free-standing devices have a full case or cabinet and integral interface. SWR meters with a clamp meter form-factor measure current through wires that are still connected to a live circuit. Rack-mounted SWR meters come with hardware such as rail guides, flanges and tabs. They are designed to be mounted in a telecommunications rack. Handheld standing wave ratio meters are designed for use while held in the hand. SWR meters with a computer-board form factor are printed circuit boards (PCBs) that plug into computer motherboards or backplanes. Electronic test equipment with other form factors is also available.
SWR meters and VSWR meters differ in terms of output interface and available features. Choices for output interface include universal serial bus (USB), general-purpose interface bus (GPIB), RS-232, binary coded decimal (BCD), and digital-to-analog (D/A). Some SWR meters have an adjustable sampling rate, alarm lights, auto-ranging features, or application software. Others provide data acquisition, data storage or logging, decibel reading, or external triggering capabilities. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated. Mirrored scales facilitate readings to a given accuracy and help operators avoid parallax errors. Range switches can be used to select the range of units to measure. SWR meters with overload protection, filters, scaling functions, and temperature compensation are also available.
SWR meters and VSWR meters may bear quality marks and comply with various international standards. The CE Mark indicates that compliance with the requirements of European Union (EU) directives that uphold standards for health, safety, and environmental protection. These standards include requirements from the Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE) directives. SWR meters that bear a CSA Mark have been tested by the Canadian Standards Association (CSA) and meet applicable standards from organizations such as Underwriters Laboratories (UL). Recognized standards for safety and performance also include IEC 61010 from the International Electrotechnical Commission (IEC).
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Selecting SWR meters and VSWR meters requires an analysis of form factors. Benchtop instruments are designed to sit atop a bench or table, typically in a laboratory setting. Free-standing devices have a full case or cabinet and integral interface. SWR meters with a clamp meter form-factor measure current through wires that are still connected to a live circuit. Rack-mounted SWR meters come with hardware such as rail guides, flanges and tabs. They are designed to be mounted in a telecommunications rack. Handheld standing wave ratio meters are designed for use while held in the hand. SWR meters with a computer-board form factor are printed circuit boards (PCBs) that plug into computer motherboards or backplanes. Electronic test equipment with other form factors is also available.
SWR meters and VSWR meters differ in terms of output interface and available features. Choices for output interface include universal serial bus (USB), general-purpose interface bus (GPIB), RS-232, binary coded decimal (BCD), and digital-to-analog (D/A). Some SWR meters have an adjustable sampling rate, alarm lights, auto-ranging features, or application software. Others provide data acquisition, data storage or logging, decibel reading, or external triggering capabilities. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated. Mirrored scales facilitate readings to a given accuracy and help operators avoid parallax errors. Range switches can be used to select the range of units to measure. SWR meters with overload protection, filters, scaling functions, and temperature compensation are also available.
SWR meters and VSWR meters may bear quality marks and comply with various international standards. The CE Mark indicates that compliance with the requirements of European Union (EU) directives that uphold standards for health, safety, and environmental protection. These standards include requirements from the Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE) directives. SWR meters that bear a CSA Mark have been tested by the Canadian Standards Association (CSA) and meet applicable standards from organizations such as Underwriters Laboratories (UL). Recognized standards for safety and performance also include IEC 61010 from the International Electrotechnical Commission (IEC).
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Stroboscope Instruments.
Stroboscopes are used for inspection and observation of moving parts by freezing or slowing down the action of a moving object. Some Instruments include a digital tachometer, as seen above. The term "stroboscope" is an expression derived from the Greek for an instrument for the observation of single phases of fast, periodic movements. If a fast rotating or oscillating object is illuminated with periodic light flashes so they always hit it in the same position, the object will appear stationary in the eyes of the observer. Industrial applications include printing and textile machines. Aviation and automotive industries are also consumers of these products.
Common configurations for stroboscope instruments include handheld, portable, fixed, or modular. Handheld instruments are specifically for using while holding in one hand. Portable instruments have handles/case/wheels etc. to make easy to move, not necessarily held in hand to use. Fixed instruments are fixed or used in one place, for example, benchtop, panel mount etc. Modular instruments have different modules for interfacing to different sensors or input ranges.
The most important parameters to consider when specifying stroboscopes include flash rate range, flash rate resolution, and flash duration. The flash rate range is the number of flashes per minute. The flash rate resolution is the accuracy of flash rate or frequency. The flash duration is defined as the amount of time, measured in microseconds, that the flash exists.
Programming is achievable through analog or digital front panels, or through a computer connection. Displays are commonly analog meters or simple visual displays, digital numerical displays, or video displays. Common features for stroboscope instruments include battery powered for full operation, built-in or self-calibration, self-test diagnostics, or personal computer software.
Common electrical outputs for stroboscope instruments include current, digital, voltage, serial, parallel, and switched or alarm. A stroboscope that outputs current is often called a transmitter. A current is imposed on the output circuit proportional to the measurement. Feedback is used to provide the appropriate current regardless of line noise, impedance, etc. Useful when sending signals long distances. A digital output is defined as any digital output other than the standard serial or parallel signals. Simple TTL logic signals are an example. Output voltage is a simple (usually linear) function of the measurement. Serial output is a standard digital output protocol (serial) such as RS232, etc. Parallel output is a standard digital output protocol (parallel) such as IEEE 488, etc. A switched or alarm output is an "output" of a change in state of switches or alarms.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Common configurations for stroboscope instruments include handheld, portable, fixed, or modular. Handheld instruments are specifically for using while holding in one hand. Portable instruments have handles/case/wheels etc. to make easy to move, not necessarily held in hand to use. Fixed instruments are fixed or used in one place, for example, benchtop, panel mount etc. Modular instruments have different modules for interfacing to different sensors or input ranges.
The most important parameters to consider when specifying stroboscopes include flash rate range, flash rate resolution, and flash duration. The flash rate range is the number of flashes per minute. The flash rate resolution is the accuracy of flash rate or frequency. The flash duration is defined as the amount of time, measured in microseconds, that the flash exists.
Programming is achievable through analog or digital front panels, or through a computer connection. Displays are commonly analog meters or simple visual displays, digital numerical displays, or video displays. Common features for stroboscope instruments include battery powered for full operation, built-in or self-calibration, self-test diagnostics, or personal computer software.
Common electrical outputs for stroboscope instruments include current, digital, voltage, serial, parallel, and switched or alarm. A stroboscope that outputs current is often called a transmitter. A current is imposed on the output circuit proportional to the measurement. Feedback is used to provide the appropriate current regardless of line noise, impedance, etc. Useful when sending signals long distances. A digital output is defined as any digital output other than the standard serial or parallel signals. Simple TTL logic signals are an example. Output voltage is a simple (usually linear) function of the measurement. Serial output is a standard digital output protocol (serial) such as RS232, etc. Parallel output is a standard digital output protocol (parallel) such as IEEE 488, etc. A switched or alarm output is an "output" of a change in state of switches or alarms.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Sound Level Meters.
Sound level meters and noise dosimeters are used in many kinds of sound and noise analysis including industrial safety, traffic and transportation noise quantification, and scientific noise measurement. They are frequently hand-held and battery-powered. Sound level meters measure real-time sound and can have functions such as signal analysis, noise dose measurement, and different time and frequency weighting.
Sound level meters and noise dosimeters are used for measuring Sound Pressure Level (SPL) and different weightings such as A-weighted SPL, C-weighted SPL, Sound Exposure Level, etc. Noise dosimeters are used for specific measurement capability for defined industrial safety criteria. A typical measure is sound exposure for an 8-hour period. These instruments can be found either individually or as one unit that covers capabilities of both products.
Two critical specifications for sound level meters and noise dosimeters are frequency range and sound level range. Frequency Range is the range of frequencies for which the meter maintains a constant sensitivity within defined boundaries. Functionally, this is the operational range of the meter. Sound level range is limited on the low end by the inherent noise of the acoustic system and on the high end by the maximum sound pressure level.
Many sound level measurement modes are available for these devices. Flat or unweighted SPL measures the straight physical quantity with no weighting. A-weighting is a frequency domain weighting based on human hearing response. This filters out low frequency sound to approximate the response of the human ear. C-weighting filters less low frequency sound than A-weighting, providing a closer representation of acoustic energy across all frequencies. A-weighted sound exposure level measurement is used for short or one-time sounds as the equivalent 1-second level. Equivalent continuous SPL is the noise level of a continuous steady sound whose time-averaged power equals that of the fluctuating noise under measurement. Percentile SPL measures the percentage of time during a given measurement period that the instantaneous measurement exceeds a given value.
Some typical features for sound level meters and noise dosimeters include ratings for outdoor use and auxiliary outputs for measurement with other instruments. These devices can also have human and hand-arm vibration measurement for industrial, environmental or occupational vibration such as power tools, nearby trains, etc. Data storage and spectrum or frequency analysis are also available.
Control panel options include analog, digital front panel or computer control. Typical machine interfaces for sound level meters and noise dosimeters are parallel and serial, although other possibilities, such as RF transmission, may be available. Displays on these instruments can be local analog or digital readouts or else can be read through a host computer or video display terminal.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Sound level meters and noise dosimeters are used for measuring Sound Pressure Level (SPL) and different weightings such as A-weighted SPL, C-weighted SPL, Sound Exposure Level, etc. Noise dosimeters are used for specific measurement capability for defined industrial safety criteria. A typical measure is sound exposure for an 8-hour period. These instruments can be found either individually or as one unit that covers capabilities of both products.
Two critical specifications for sound level meters and noise dosimeters are frequency range and sound level range. Frequency Range is the range of frequencies for which the meter maintains a constant sensitivity within defined boundaries. Functionally, this is the operational range of the meter. Sound level range is limited on the low end by the inherent noise of the acoustic system and on the high end by the maximum sound pressure level.
Many sound level measurement modes are available for these devices. Flat or unweighted SPL measures the straight physical quantity with no weighting. A-weighting is a frequency domain weighting based on human hearing response. This filters out low frequency sound to approximate the response of the human ear. C-weighting filters less low frequency sound than A-weighting, providing a closer representation of acoustic energy across all frequencies. A-weighted sound exposure level measurement is used for short or one-time sounds as the equivalent 1-second level. Equivalent continuous SPL is the noise level of a continuous steady sound whose time-averaged power equals that of the fluctuating noise under measurement. Percentile SPL measures the percentage of time during a given measurement period that the instantaneous measurement exceeds a given value.
Some typical features for sound level meters and noise dosimeters include ratings for outdoor use and auxiliary outputs for measurement with other instruments. These devices can also have human and hand-arm vibration measurement for industrial, environmental or occupational vibration such as power tools, nearby trains, etc. Data storage and spectrum or frequency analysis are also available.
Control panel options include analog, digital front panel or computer control. Typical machine interfaces for sound level meters and noise dosimeters are parallel and serial, although other possibilities, such as RF transmission, may be available. Displays on these instruments can be local analog or digital readouts or else can be read through a host computer or video display terminal.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Rheostats and Potentiometers.
Potentiometers, rheostats and trimmers are three-terminal resistors that are used to measure or divide voltages, and to protect or control circuits. Potentiometers are variable resistors that are adjusted with a knob or dial. Rheostats and trimmers are types of potentiometers. With a rheostat, a third “wiper” terminal is shorted to one of two fixed terminals. The wiper terminal has a resistance which varies with its position, and the two fixed terminals are connected by a fixed resistance. Trimmers are factory-set devices that require infrequent adjustments. They feature a slotted, actuator-type style and can be adjusted with a special tool or screwdriver. Other types of potentiometers, rheostats and trimmers are also available. These include standard potentiometers, mechanical devices in which the output resistance is set by a shaft; and digital potentiometers, which set an output resistance by sending a digital signal through an electrical interface.
Potentiometers, rheostats and trimmers carry specifications for potentiometer category and actuator configuration. Industrial-grade potentiometers are protected by an enclosure, typically one that is rated by the National Electrical Manufacturers Association (NEMA). Typically, industrial-grade products are gear-driven and have connector outputs. These potentiometers, rheostats and trimmers resist the ingress of dirt and dust, and last longer than unenclosed potentiometers. Discrete-board components, another potentiometer category, are also commonly available. In terms of actuator configuration, choices include single-turn, multi-turn, and slide. With single-turn devices, the shaft rotation is limited to less than or equal to 360 degrees. By contrast, multi-turn potentiometers, rheostats and trimmers can be rotated multiple times, with as many as 15 or 20 turns from stop to stop. Slide-actuated products require the user to move a handle instead of rotating a knob.
Potentiometers, rheostats and trimmers differ in terms of construction, mounting or packaging, performance specifications and features. Choices for construction include ceramic composition, carbon composition, carbon film, cermet, thick film, thin film, metal alloy, metal film, and metal oxide. Wirewound resistors are also available. There are many mounting and packaging styles for potentiometers, rheostats and trimmers. Choices include surface mount technology (SMT), bolt-on or chassis, panel mount, through-hole technology (THT), axial leads, gull-wing leads, J-leads, radial leads, screw terminals and tab terminals. The most important performance specifications to consider when selecting potentiometers, rheostats and trimmers include resistance range, tolerance, operating alternating current (AC) voltage, operating direct current (DC) voltage, and operating temperature.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Potentiometers, rheostats and trimmers carry specifications for potentiometer category and actuator configuration. Industrial-grade potentiometers are protected by an enclosure, typically one that is rated by the National Electrical Manufacturers Association (NEMA). Typically, industrial-grade products are gear-driven and have connector outputs. These potentiometers, rheostats and trimmers resist the ingress of dirt and dust, and last longer than unenclosed potentiometers. Discrete-board components, another potentiometer category, are also commonly available. In terms of actuator configuration, choices include single-turn, multi-turn, and slide. With single-turn devices, the shaft rotation is limited to less than or equal to 360 degrees. By contrast, multi-turn potentiometers, rheostats and trimmers can be rotated multiple times, with as many as 15 or 20 turns from stop to stop. Slide-actuated products require the user to move a handle instead of rotating a knob.
Potentiometers, rheostats and trimmers differ in terms of construction, mounting or packaging, performance specifications and features. Choices for construction include ceramic composition, carbon composition, carbon film, cermet, thick film, thin film, metal alloy, metal film, and metal oxide. Wirewound resistors are also available. There are many mounting and packaging styles for potentiometers, rheostats and trimmers. Choices include surface mount technology (SMT), bolt-on or chassis, panel mount, through-hole technology (THT), axial leads, gull-wing leads, J-leads, radial leads, screw terminals and tab terminals. The most important performance specifications to consider when selecting potentiometers, rheostats and trimmers include resistance range, tolerance, operating alternating current (AC) voltage, operating direct current (DC) voltage, and operating temperature.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on RF Generators.
RF generators provide power for thin film processing equipment, semiconductor fabrication systems, plasma generation, induction heating, telecommunications applications, and radar equipment. RF generators are also used to power computers, computer peripherals, medical devices, magnetic devices, and test equipment. Single-phase AC inputs are used with lower voltage applications. Three-phase AC inputs are used with high voltage power supplies. Products that meet U.S. military specifications (MIL-SPEC) accept high frequency inputs, typically in the 400 Hz range. Common AC input voltages include 115, 208, 230, and 480 VAC. Common AC input frequencies are 50 and 60 Hz. Output specifications for RF generators include output frequency, voltage and current; adjustable frequency, voltage, and current; and output power, an amount expressed in watts (W). Automatic frequency tuning (AFT) reduces harmonics, improves speed and reliability, and eliminates the tuning elements found in many traditional networks.
There are several mounting styles and form factors for RF generators. Surface mount technology (SMT) adds components to a printed circuit board (PCB) by soldering component leads or terminals to the top surface of the board. By contrast, through hole technology (THT) mounts components by inserting component leads through holes in the board and then soldering the leads in place on the opposite side of the board. Some RF generators are rack-mounted, wall-mounted, chassis-mounted, or designed to sit atop a desktop or shelf. Others have an open frame or mount on a standard DIN rail. DIN is an acronym for Deutsches Institut für Normung (DIN), a German national organization for standardization. Some suppliers provide RF generators that enclose the input and output connection, include a floor-standing cabinet, or have a PCB form factor. Modular products are also available.
Selecting RF generators requires an analysis of special features. Battery backups provide emergency power for continuous outputs. Hot swappable devices can be replaced without shutting down the system. Overcurrent protection limits or shuts down the current output during overcurrent conditions. Similarly, overvoltage protection limits or shuts down the voltage output during overvoltage conditions. Some RF generators are temperature compensated, water cooled, fan cooled, or include an integral heatsink. Others provide DC outputs, a computer interface that can be used for remote monitoring or control, or a remote on/off switch. Power factor correction is used to correct the phase difference between voltage and current in order to optimize power output. Pure sine devices produce very high quality, sine waveform outputs. Weatherproof products can withstand prolonged exposure to outdoor conditions such as rain or snow.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
There are several mounting styles and form factors for RF generators. Surface mount technology (SMT) adds components to a printed circuit board (PCB) by soldering component leads or terminals to the top surface of the board. By contrast, through hole technology (THT) mounts components by inserting component leads through holes in the board and then soldering the leads in place on the opposite side of the board. Some RF generators are rack-mounted, wall-mounted, chassis-mounted, or designed to sit atop a desktop or shelf. Others have an open frame or mount on a standard DIN rail. DIN is an acronym for Deutsches Institut für Normung (DIN), a German national organization for standardization. Some suppliers provide RF generators that enclose the input and output connection, include a floor-standing cabinet, or have a PCB form factor. Modular products are also available.
Selecting RF generators requires an analysis of special features. Battery backups provide emergency power for continuous outputs. Hot swappable devices can be replaced without shutting down the system. Overcurrent protection limits or shuts down the current output during overcurrent conditions. Similarly, overvoltage protection limits or shuts down the voltage output during overvoltage conditions. Some RF generators are temperature compensated, water cooled, fan cooled, or include an integral heatsink. Others provide DC outputs, a computer interface that can be used for remote monitoring or control, or a remote on/off switch. Power factor correction is used to correct the phase difference between voltage and current in order to optimize power output. Pure sine devices produce very high quality, sine waveform outputs. Weatherproof products can withstand prolonged exposure to outdoor conditions such as rain or snow.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes On Ultrasonic Instruments.
Ultrasonic instruments use beams of high frequency, short wave signals to inspect, monitor, and measure materials and components. Ultrasonic energy is introduced into tested materials or components and then retrieved for subsequent analysis. There are several basic types of ultrasonic instruments. Acoustic emissions instruments and fault detectors are used to monitor conditions in a variety of mechanical, electrical and process systems. When a break or deformation occurs, highly-sensitive acoustic emission sensors detect the high frequency bursts emitted during the event. Problems such as electrical shorting, corona discharging and arcing also produce detectable ultrasonic signals. Acoustic emissions instruments are often used to determine the structural adequacy of steam traps, pipes, valves, tanks, and pressure vessels. Fault detectors are used to inspect bearings, gearboxes or other rotating machinery for changes due to wear or load. Other types of ultrasonic instruments include thickness gauges, flaw detectors, corrosion instruments, leak detectors, and material condition testers. Leak detectors are used to detect holes and cracks, defective seals, channel leaks, contaminated materials, or missing closures. Material condition testers are used to evaluate materials properties or conditions such as hardness, residual stress, strength, elasticity or density.
Most ultrasonic instruments consist of a non-contact focusing probe and integral meter. Form factors, mounting styles, and optional features are important specifications to consider. Some devices are designed to sit atop a bench or desktop. Others are designed to be mounted in a rack or cabinet. Printed circuit boards (PCB) that contain ultrasonic instruments attach to enclosures or plug directly into computer backplanes. Complete monitoring systems are used for the continuous measurement of flaws, thickness, or corrosion. Portable, hand held, and mobile products are also available. In terms of features, ultrasonic instruments include sorting gates or sound an alarm if a reading is outside of an acceptable range of values. Handheld or portable devices often provide data logging capabilities and can be interfaced to a computer or other electronic device. The maximum number of channel or probes is an additional consideration when selecting ultrasonic instruments. Specialized products are used for specific applications such as pipeline monitoring and aircraft component inspection.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Most ultrasonic instruments consist of a non-contact focusing probe and integral meter. Form factors, mounting styles, and optional features are important specifications to consider. Some devices are designed to sit atop a bench or desktop. Others are designed to be mounted in a rack or cabinet. Printed circuit boards (PCB) that contain ultrasonic instruments attach to enclosures or plug directly into computer backplanes. Complete monitoring systems are used for the continuous measurement of flaws, thickness, or corrosion. Portable, hand held, and mobile products are also available. In terms of features, ultrasonic instruments include sorting gates or sound an alarm if a reading is outside of an acceptable range of values. Handheld or portable devices often provide data logging capabilities and can be interfaced to a computer or other electronic device. The maximum number of channel or probes is an additional consideration when selecting ultrasonic instruments. Specialized products are used for specific applications such as pipeline monitoring and aircraft component inspection.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Thickness Gauges.
Thickness gauges are used to make precise dimensional cross section measurements on a wide variety of coatings and materials including steel, plastic, glass, rubber, ceramics, paint, electroplated layers, enamels, pavement, multi-layer deposits, etc. There are many mechanical, nondestructive and destructive techniques available to accomplish this task: IR or nuclear gauges, eddy current, magnetic particle, laser, ultrasonic, coulometric, and X-ray, are only a few of the many techniques.
Beta, IR or nuclear gauge testing involves the absorption of x-ray, infrared or Beta particle radiation to measure the thickness of materials or coatings. On nonmetallic materials such as paper or plastic films or webs, radiation is transmitted through the material and a radiation or Geiger-Muller detector is located on the other side to measure radiation levels. On coated metallic materials, the radiation or Geiger-Muller detector is located on the same side and backscattered radiation is measured.
Coulometric instruments use an electrochemical process to etch away a plated or metallic layer at a predetermined rate. The amount of time to remove the plated layer provides an indication of coating thickness. Coulometric measurement is a destructive technique.
Eddy current, penetrating radar and other electromagnetic thickness gauge techniques are used to detect or measure flaws, bond or weld integrity, thickness, electrical conductivity, coating thickness, detect the presence of rebar or metals. Eddy current is the most widely applied electromagnetic NDT technique. The eddy current method is also useful in sorting alloys and verifying heat treatment. Eddy current thickness gauges use an electromagnet to induce an eddy current in a conductive sample. The response of the material to the induced current is sensed. Since the probe does not have to contact the work surface, eddy current testing is useful on rough surfaces or surfaces with wet films or coatings.
Laser thickness gauges include methods such as laser shearography, magneto-optical, holographic interferometry or other optical techniques to detect flaws, residual stress or measure thickness.
Magnetic particle or current flow uses an external magnet magnetizes the part. Magnetic poles created at flaws, cracks or other discontinuities attract magnetic particles. The magnetic particles are fine iron oxide particles (0.125 to 60 microns) with a high permeability (easily magnetized) and low retentivity (ability to stay magnetized). Three methods are typically applied: dry non fluorescent, wet non fluorescent and wet fluorescent.
Mechanical gauges physically contact a sample to measure thickness using a gap and/or comparison to a known dimensional standard or master. Micrometers and calipers are common types of mechanical gauges used for dimensional gauging.
Ultrasonic instruments use beams of high frequency acoustic energy that are introduced into the material and subsequently retrieved. Thickness or distance calculations are based on the speed of sound through the material being evaluated. The most widely used of all UT techniques is the pulse-echo technique.
Thickness gauges using penetrating X-rays or gamma rays to capture images of the internal structure or a part or finished product. The density and composition of the internal features will alter the intensity or density of these features in the X-ray image. Densitometers are used to quantify the density variations in the X-ray image. Penetrameters or other X-ray thickness gauge references are located with the part during imaging for sizing of internal cracks, pores, defects or other features.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Beta, IR or nuclear gauge testing involves the absorption of x-ray, infrared or Beta particle radiation to measure the thickness of materials or coatings. On nonmetallic materials such as paper or plastic films or webs, radiation is transmitted through the material and a radiation or Geiger-Muller detector is located on the other side to measure radiation levels. On coated metallic materials, the radiation or Geiger-Muller detector is located on the same side and backscattered radiation is measured.
Coulometric instruments use an electrochemical process to etch away a plated or metallic layer at a predetermined rate. The amount of time to remove the plated layer provides an indication of coating thickness. Coulometric measurement is a destructive technique.
Eddy current, penetrating radar and other electromagnetic thickness gauge techniques are used to detect or measure flaws, bond or weld integrity, thickness, electrical conductivity, coating thickness, detect the presence of rebar or metals. Eddy current is the most widely applied electromagnetic NDT technique. The eddy current method is also useful in sorting alloys and verifying heat treatment. Eddy current thickness gauges use an electromagnet to induce an eddy current in a conductive sample. The response of the material to the induced current is sensed. Since the probe does not have to contact the work surface, eddy current testing is useful on rough surfaces or surfaces with wet films or coatings.
Laser thickness gauges include methods such as laser shearography, magneto-optical, holographic interferometry or other optical techniques to detect flaws, residual stress or measure thickness.
Magnetic particle or current flow uses an external magnet magnetizes the part. Magnetic poles created at flaws, cracks or other discontinuities attract magnetic particles. The magnetic particles are fine iron oxide particles (0.125 to 60 microns) with a high permeability (easily magnetized) and low retentivity (ability to stay magnetized). Three methods are typically applied: dry non fluorescent, wet non fluorescent and wet fluorescent.
Mechanical gauges physically contact a sample to measure thickness using a gap and/or comparison to a known dimensional standard or master. Micrometers and calipers are common types of mechanical gauges used for dimensional gauging.
Ultrasonic instruments use beams of high frequency acoustic energy that are introduced into the material and subsequently retrieved. Thickness or distance calculations are based on the speed of sound through the material being evaluated. The most widely used of all UT techniques is the pulse-echo technique.
Thickness gauges using penetrating X-rays or gamma rays to capture images of the internal structure or a part or finished product. The density and composition of the internal features will alter the intensity or density of these features in the X-ray image. Densitometers are used to quantify the density variations in the X-ray image. Penetrameters or other X-ray thickness gauge references are located with the part during imaging for sizing of internal cracks, pores, defects or other features.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Electronic Loads.
Electronic loads and load banks are used to test electrical and electronic equipment. They mimic load requirements for testing and troubleshooting purposes. There are four basic types of electronic loads: benchtop, slot, modular and system. Benchtop loads are relatively inexpensive, but limited in terms of range and accuracy. Slot loads measure a single set of variables and are similar to benchtop loads. Modular loads include a computer chassis and are designed for applications with changing load configurations. Although modular loads more than one chassis are available, devices with a single chassis can be configured to act as a single load in dynamic modes. System loads are designed for near-continuous duty and include an integral transient generator. They are more expensive than other types of electronic loads, but provide a wider range of features.
Selecting electronic loads requires an analysis of performance specifications and product features. Input specifications include power, voltage, current, and frequency. Modular loads also vary in terms of number of loads per chassis. As a rule, smaller electrical loads require fewer card slots. Measurement type, efficiency, and emulation mode are additional considerations when selecting electronic loads. Measurement types include voltage, current, peak-current, frequency, crest-factor, power-factor and true power. Efficiency, a measure of power, is usually expressed as a percentage. Electronic loads provide up to five emulation modes: constant-current, constant-voltage, constant-resistance, constant-power, and short circuit. Alternating current (AC) and direct current (DC) outputs are characterized as high, low, or medium power. In terms of features, electronic loads often include a graphical user interface (GUI) and integral software. Test results can be sent to a digital front panel, a printer, or a personal computer (PC).
Electronic loads are used for design verification, multiple unit production testing, and troubleshooting inbound devices for repairs. Some products are used to test AC power supplies, DC power supplies, switching power supplies, or uninterruptible power supplies (UPS). Others are designed to test fuel cells, inverters, telecommunications rectifiers, batteries and battery charges. Programmable electronic loads are used with automatic testing equipment (ATE) and a variety of units under test (UUT).
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Selecting electronic loads requires an analysis of performance specifications and product features. Input specifications include power, voltage, current, and frequency. Modular loads also vary in terms of number of loads per chassis. As a rule, smaller electrical loads require fewer card slots. Measurement type, efficiency, and emulation mode are additional considerations when selecting electronic loads. Measurement types include voltage, current, peak-current, frequency, crest-factor, power-factor and true power. Efficiency, a measure of power, is usually expressed as a percentage. Electronic loads provide up to five emulation modes: constant-current, constant-voltage, constant-resistance, constant-power, and short circuit. Alternating current (AC) and direct current (DC) outputs are characterized as high, low, or medium power. In terms of features, electronic loads often include a graphical user interface (GUI) and integral software. Test results can be sent to a digital front panel, a printer, or a personal computer (PC).
Electronic loads are used for design verification, multiple unit production testing, and troubleshooting inbound devices for repairs. Some products are used to test AC power supplies, DC power supplies, switching power supplies, or uninterruptible power supplies (UPS). Others are designed to test fuel cells, inverters, telecommunications rectifiers, batteries and battery charges. Programmable electronic loads are used with automatic testing equipment (ATE) and a variety of units under test (UUT).
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Electrical Test Probes.
Electrical test probes are used to establish a connection between a circuit under test and the measuring instrument. There are several basic types of products. Voltage probes are used to measure voltage. Current probes are used to measure current. Oscilloscope probes have a specified operating bandwidth and, in some cases, built-in switchable attenuators. Differential probes are used to measure differential signals which are referenced to each other instead of ground. By contrast, single-ended test probes are electrical test probes used to measure signals referenced to ground. Logic probes are used to measure logic levels in digital circuits. Semiconductor probes and high-density probes are fine point, spring loaded probes that are usually mounted in a test jig. These electrical test probes are used to test semiconductor interconnects and high-density circuit boards.
Other types of electrical test probes include coaxial probes, polarity probes, continuity probes, high frequency probes, high voltage probes, magnetic probes, and optical probes. A coaxial test probe is a spring loaded, signal-conducting probe insulated from its shell or shielding tube by a dielectric material. Coaxial test probes have rated nominal impedance similar to a coaxial cable. A polarity probe automatically determines the polarity of the circuit under test. A continuity probe is used to test circuit conditions for continuous connection. Typically, continuity test probes are bundled with a continuity tester. A high voltage probe is used to measure high voltage signals. Magnetic probes sense magnetic fields in solenoid-operated devices, stepper switches, relays, valves and coils. Optical probes are electrical test probes that convert optical signals into electrical signals for convenient analysis of oscilloscopes and other devices.
Selecting electrical test probes requires an analysis of performance specifications. The attenuation factor is the amount by which the electrical test probe reduces the amplitude of the signal being measured. This extends the measurement range for an instrument such as an oscilloscope. For instance, a 10X probe reduces the measured signal to 0.1 of its amplitude, allowing the test instrument to measure signals ten times larger than what its maximum range allows. Choices typically include 1X, 10X, 100X, 500X, and 1000X.
There are many different configurations for electrical test probes. An alligator clip electrical test probe has a spring-loaded jaw with serrated teeth that grip the point being measured. A bent metal electrical test probe has bent metal contacts, relatively fine pieces of metal that are formed into a curvilinear shape in order to provide a cantilever effect. Normally, the metal contacts are then insert-molded or stuffed into a nonconductive carrier. A portion of the metal contact protrudes beneath the carrier for attachment to a printed circuit board (PCB) by surface mount or through-hole interconnection. A board or chip configuration has a specialized probe tip that is used to examine signals on PCBs and integrated circuit (IC) chips. Other configurations include conductive elastomers, extended-fine tip, flat blade, hook, pin-and-socket, pincher, probe card, spade lug, spring loaded, and wireless.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Other types of electrical test probes include coaxial probes, polarity probes, continuity probes, high frequency probes, high voltage probes, magnetic probes, and optical probes. A coaxial test probe is a spring loaded, signal-conducting probe insulated from its shell or shielding tube by a dielectric material. Coaxial test probes have rated nominal impedance similar to a coaxial cable. A polarity probe automatically determines the polarity of the circuit under test. A continuity probe is used to test circuit conditions for continuous connection. Typically, continuity test probes are bundled with a continuity tester. A high voltage probe is used to measure high voltage signals. Magnetic probes sense magnetic fields in solenoid-operated devices, stepper switches, relays, valves and coils. Optical probes are electrical test probes that convert optical signals into electrical signals for convenient analysis of oscilloscopes and other devices.
Selecting electrical test probes requires an analysis of performance specifications. The attenuation factor is the amount by which the electrical test probe reduces the amplitude of the signal being measured. This extends the measurement range for an instrument such as an oscilloscope. For instance, a 10X probe reduces the measured signal to 0.1 of its amplitude, allowing the test instrument to measure signals ten times larger than what its maximum range allows. Choices typically include 1X, 10X, 100X, 500X, and 1000X.
There are many different configurations for electrical test probes. An alligator clip electrical test probe has a spring-loaded jaw with serrated teeth that grip the point being measured. A bent metal electrical test probe has bent metal contacts, relatively fine pieces of metal that are formed into a curvilinear shape in order to provide a cantilever effect. Normally, the metal contacts are then insert-molded or stuffed into a nonconductive carrier. A portion of the metal contact protrudes beneath the carrier for attachment to a printed circuit board (PCB) by surface mount or through-hole interconnection. A board or chip configuration has a specialized probe tip that is used to examine signals on PCBs and integrated circuit (IC) chips. Other configurations include conductive elastomers, extended-fine tip, flat blade, hook, pin-and-socket, pincher, probe card, spade lug, spring loaded, and wireless.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Power Meters.
Power meters are used for high-accuracy measurements of power over a wide-frequency bandwidth, and from both AC and DC circuits. Measurements can be obtained for single-phase and three-phase AC systems. Some power meters can measure true RMS power. Root mean square (RMS) is the value obtained when the maximum voltage or current is divided by the square root of two. Power meters can be used for the measurement of power in various conditions, including half-wave and full-wave rectified waveforms, mixed AC/DC waveforms, and distorted waveforms.
Performance specifications for power meters include power range, number of channels, sampling rate, and the type of power to measure. There are four measurement types: active power, apparent power, reactive power and power factor. Active power is the time rate of transferring or transforming energy. The electrical power at a single terminal-pair is the product of the voltage and current. Apparent power is the product of the RMS values of voltage and current. Reactive power is the product of the RMS value of the voltage and the RMS value of the quadrature component of the current. Finally, power factor or quality factor is the ratio of active power to apparent power.
Phase angle parameters are also important product specifications for power meters. The phase angle is the angle, in degrees, between the current waveform and the voltage waveform. A leading phase angle means that the current is ahead of the voltage and the load is capacitive. If the current lags the voltage, then the phase angle is lagging and the load is inductive.
Power meters are available with a variety of features. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated (Wh and Ah). Scaling functions allow the potential transformer and current transformer ratio to be preset. Power meters can also support a wide range of current sensors used for evaluating inverter driven equipment and high frequency lighting equipment. Automatic range switching means that when the measured value falls out of the rated range, the meter switches automatically to the appropriate unit for the range being measured. Harmonic analysis is phase measurement between three-phase inputs and measurement of active, reactive or apparent power of the fundamental wave. Other, more general features for power meters include filtering, data logging, event triggering, and application software.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Performance specifications for power meters include power range, number of channels, sampling rate, and the type of power to measure. There are four measurement types: active power, apparent power, reactive power and power factor. Active power is the time rate of transferring or transforming energy. The electrical power at a single terminal-pair is the product of the voltage and current. Apparent power is the product of the RMS values of voltage and current. Reactive power is the product of the RMS value of the voltage and the RMS value of the quadrature component of the current. Finally, power factor or quality factor is the ratio of active power to apparent power.
Phase angle parameters are also important product specifications for power meters. The phase angle is the angle, in degrees, between the current waveform and the voltage waveform. A leading phase angle means that the current is ahead of the voltage and the load is capacitive. If the current lags the voltage, then the phase angle is lagging and the load is inductive.
Power meters are available with a variety of features. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated (Wh and Ah). Scaling functions allow the potential transformer and current transformer ratio to be preset. Power meters can also support a wide range of current sensors used for evaluating inverter driven equipment and high frequency lighting equipment. Automatic range switching means that when the measured value falls out of the rated range, the meter switches automatically to the appropriate unit for the range being measured. Harmonic analysis is phase measurement between three-phase inputs and measurement of active, reactive or apparent power of the fundamental wave. Other, more general features for power meters include filtering, data logging, event triggering, and application software.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Phase Rotation Meters.
Phase Rotation Meters (phase testers, phase rotation meters) are used to check the phase sequence and phase orientation in three-phase electrical systems. They are used for energy measurements, and the monitoring for the quality of audio and video transmissions. Correct phase matching is also important in energy metering applications since phase mismatches between channels may cause significant measurement errors at low power factors. Bandwidth, sampling rate, maximum channels, and operating temperature are important parameters to specify when selecting phase meters. Bandwidth is the frequency range over which current or voltage is measured. Sampling rate is the frequency that a digital meter tests an analog signal and converts to a digital value.
General specifications for phase meters, phase testers and phase rotation meters include display type and form factor. There are two choices for display type: analog and digital. Form factors are listed as bench or free-standing, clamp meter, rack-mounted, handheld, or computer compounds. Benchtop phase meters are designed to sit atop a bench or table; or are free-standing units with a full casing, cabinet, and integral interface. Phase meters that function as clamp meters can measure current through wires that are still connected to a live circuit. Rack-mounted electrical test equipment is designed for mounting in telecommunications racks and includes hardware such as rail guides, flanges and tabs. Handheld devices are designed for use while held in one hand. Phase meters with a computer-board form factor are printed circuit boards (PCBs) that plug into computer backplanes or motherboards.
Phase meters, phase testers and phase rotation meters may bear quality marks and comply with national or international standards for safety and performance. The CE Mark indicates that product complies with the relevant European Union (EU) directives and upholds recognized standards for health, safety, and environmental protection. These standards include the requirements defined in the EU’s Restriction of Hazardous Substances (RoHS).
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
General specifications for phase meters, phase testers and phase rotation meters include display type and form factor. There are two choices for display type: analog and digital. Form factors are listed as bench or free-standing, clamp meter, rack-mounted, handheld, or computer compounds. Benchtop phase meters are designed to sit atop a bench or table; or are free-standing units with a full casing, cabinet, and integral interface. Phase meters that function as clamp meters can measure current through wires that are still connected to a live circuit. Rack-mounted electrical test equipment is designed for mounting in telecommunications racks and includes hardware such as rail guides, flanges and tabs. Handheld devices are designed for use while held in one hand. Phase meters with a computer-board form factor are printed circuit boards (PCBs) that plug into computer backplanes or motherboards.
Phase meters, phase testers and phase rotation meters may bear quality marks and comply with national or international standards for safety and performance. The CE Mark indicates that product complies with the relevant European Union (EU) directives and upholds recognized standards for health, safety, and environmental protection. These standards include the requirements defined in the EU’s Restriction of Hazardous Substances (RoHS).
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Power Quality Analyzers.
Power quality analyzers measure and monitor electrical power parameters to avoid disturbances, track steady-state variations, and ensure the reliability of power distribution systems. Disturbances are measurable events that are triggered by abnormalities in voltage or current. Steady-state variations compare changes to normal values and are measured by sampling voltage and/or current levels over time. To track disturbances and steady-state variations, power quality analyzers present information as individual events, trends, or statistical summaries. Examples of individual events include voltage spikes and brownouts. Power quality analyzers can also measure transients such as primary magnitude, time of occurrence, and rate of rise. Some devices are powered by the system being tested. Others use battery power. Power quality analyzers with integral AC current clamps are also available.
Power quality analyzers track several electrical and power parameters. Electrical parameters include AC voltage, AC current, and frequency. Power parameters include demand and peak demand. Demand is the actual amount of power that the monitored system uses. Peak demand is the maximum amount of power that can be used. Typically, power parameters are measured in watts (W), volt amperes (VA), and volt ampere reactives (VAR). Watts are units of electrical power that indicate the rate of energy produced or consumed by an electrical device. Volt amperes equal the current flowing in a circuit multiplied by the voltage of that circuit. Volt ampere reactives identify the reactive component of volt amperes.
There are several power quality parameters for power quality analyzers. Root mean square (RMS) voltage is obtained by dividing the peak voltage by the square root of 2. Similarly, RMS current is obtained by dividing the peak current by the square root of 2. Current and voltage harmonics can cause problems such as the excessive heating of wiring, connections, motors, and transformers. Harmonics can also cause the inadvertent tripping of circuit breakers. Total harmonic distortion (THD) is a percentage of the total output RMS voltage. Other power quality parameters include power factor, the ratio of actual power to apparent power. Another parameter, K-factor, is a numeric value that accounts for both the magnitude and frequency of the component of a current waveform. Typically, K-factor is used to indicate whether a full-rated transformer is designed to handle non-linear loads.
Data interfaces for power quality analyzers include general-purpose interface bus (GPIB), universal serial bus (USB), RS232, RS485, and Ethernet. GPIB is designed to connect computers, peripherals and laboratory instruments so that data and control information can pass between them. USB is a 4-wire, 12-Mbps serial bus for low-to-medium peripheral device connections to personal computers (PCs), including keyboards, mice, modems, printers, and monitor controls. Ethernet is a widely used local area network (LAN) technology that specifies how data is placed on and retrieved from a common transmission medium. Power quality analyzers that can convert digital to analog signals are also available.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Power quality analyzers track several electrical and power parameters. Electrical parameters include AC voltage, AC current, and frequency. Power parameters include demand and peak demand. Demand is the actual amount of power that the monitored system uses. Peak demand is the maximum amount of power that can be used. Typically, power parameters are measured in watts (W), volt amperes (VA), and volt ampere reactives (VAR). Watts are units of electrical power that indicate the rate of energy produced or consumed by an electrical device. Volt amperes equal the current flowing in a circuit multiplied by the voltage of that circuit. Volt ampere reactives identify the reactive component of volt amperes.
There are several power quality parameters for power quality analyzers. Root mean square (RMS) voltage is obtained by dividing the peak voltage by the square root of 2. Similarly, RMS current is obtained by dividing the peak current by the square root of 2. Current and voltage harmonics can cause problems such as the excessive heating of wiring, connections, motors, and transformers. Harmonics can also cause the inadvertent tripping of circuit breakers. Total harmonic distortion (THD) is a percentage of the total output RMS voltage. Other power quality parameters include power factor, the ratio of actual power to apparent power. Another parameter, K-factor, is a numeric value that accounts for both the magnitude and frequency of the component of a current waveform. Typically, K-factor is used to indicate whether a full-rated transformer is designed to handle non-linear loads.
Data interfaces for power quality analyzers include general-purpose interface bus (GPIB), universal serial bus (USB), RS232, RS485, and Ethernet. GPIB is designed to connect computers, peripherals and laboratory instruments so that data and control information can pass between them. USB is a 4-wire, 12-Mbps serial bus for low-to-medium peripheral device connections to personal computers (PCs), including keyboards, mice, modems, printers, and monitor controls. Ethernet is a widely used local area network (LAN) technology that specifies how data is placed on and retrieved from a common transmission medium. Power quality analyzers that can convert digital to analog signals are also available.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes On Oscilloscopes.
Oscilloscopes translate an electronic signal into a pattern or waveform on a screen. As it is traced across the screen, the waveform creates a signature of the signal's characteristics. Specifications for oscilloscopes include bandwidth, number of input channels, number of trigger inputs, and resolution. Bandwidth is the frequency range over which oscilloscopes meet their accuracy specifications. Accuracy degrades at lower and lower frequencies unless the oscilloscope is capable of direct current (DC) response. Accuracy also degrades at higher frequencies near resonance and beyond, causing the output response to roll off. The number of input channels is the number of possible, simultaneous signal measurements. Channels can be differential or single-ended. The number of trigger inputs is the number of digital or discrete channels that oscilloscopes use for low-level on-off signals. Resolution refers to the degree of fineness of the digital word representing the analog value. A ten-bit number contains 210 (1024) increments and allows a 0 - 10 V signal to be resolved into approximately 0.01 V increments. A 12-bit representation provides 212 (4096) increments of 0.0024 V for the same signal.
Oscilloscopes use a host interface to communicate with a host computer or other electronic device. Oscilloscopes can use a serial port, parallel port, modem or telephone line, universal serial bus (USB), general-purpose interface bus (GPIB), small computer systems interface (SCSI), or Ethernet connection. Serial ports transfer data one bit a time. RS232, RS422, and RS485 are common serial interfaces. Parallel ports transfer more than one bit at time. Personal computer (PC) printer ports and Centronics ports use parallel communications. Modems (modulators/demodulators) are devices or programs that enable a computer to transmit data over telephone lines. Universal serial bus (USB) is a 4-wire, 12-Mbps serial bus for low-to-medium speed peripheral device connections to personal computers (PC). The general-purpose interface bus (GPIB) is designed to connect computers, peripherals and laboratory instruments so that data and control information can pass between them. Small computer systems interface (SCSI) is an intelligent I/O parallel peripheral bus with a standard, device-independent protocol that allows many peripheral devices to be connected to the SCSI port. Other specialized and proprietary host interfaces for oscilloscopes are also available.
Oscilloscopes provide many different features. Some devices have a relay or switch output for limit detection or other state signalling. Others are powered by a replaceable or rechargeable battery, or are designed to be used while held in one hand. Oscilloscopes that are rated for high-power applications can monitor and/or display currents and voltages associated with electrical power or high-power switching. Typically, these currents and voltages are much higher that standard sensor signal levels. In terms of storage capacity, oscilloscopes can include a hard drive, nonvolatile memory, or on-board random access memory (RAM). Removable storage media devices such as tapes, diskettes, and PCMCIA cards are also available.
Oscilloscopes that are marketed in Europe Union (EU) countries should meet two important directives: Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE). RoHS requires manufacturers of electronic and electrical equipment to demonstrate that their products contain only minimal levels of lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyl and polybrominated diphenyl ether. Waste Electrical and Electronics Equipment (WEEE) is and EU directive that is designed to encourage the reuse, recycling and recovery of electrical and electronic equipment. WEEE establishes requirements and criteria for the collection, treatment, recycling and recovery of such devices. WEEE also makes producers responsible for financing these activities, and requires retailers and distributors to provide a way for consumers to return used or obsolete equipment at no charge.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Oscilloscopes use a host interface to communicate with a host computer or other electronic device. Oscilloscopes can use a serial port, parallel port, modem or telephone line, universal serial bus (USB), general-purpose interface bus (GPIB), small computer systems interface (SCSI), or Ethernet connection. Serial ports transfer data one bit a time. RS232, RS422, and RS485 are common serial interfaces. Parallel ports transfer more than one bit at time. Personal computer (PC) printer ports and Centronics ports use parallel communications. Modems (modulators/demodulators) are devices or programs that enable a computer to transmit data over telephone lines. Universal serial bus (USB) is a 4-wire, 12-Mbps serial bus for low-to-medium speed peripheral device connections to personal computers (PC). The general-purpose interface bus (GPIB) is designed to connect computers, peripherals and laboratory instruments so that data and control information can pass between them. Small computer systems interface (SCSI) is an intelligent I/O parallel peripheral bus with a standard, device-independent protocol that allows many peripheral devices to be connected to the SCSI port. Other specialized and proprietary host interfaces for oscilloscopes are also available.
Oscilloscopes provide many different features. Some devices have a relay or switch output for limit detection or other state signalling. Others are powered by a replaceable or rechargeable battery, or are designed to be used while held in one hand. Oscilloscopes that are rated for high-power applications can monitor and/or display currents and voltages associated with electrical power or high-power switching. Typically, these currents and voltages are much higher that standard sensor signal levels. In terms of storage capacity, oscilloscopes can include a hard drive, nonvolatile memory, or on-board random access memory (RAM). Removable storage media devices such as tapes, diskettes, and PCMCIA cards are also available.
Oscilloscopes that are marketed in Europe Union (EU) countries should meet two important directives: Restriction of Hazardous Substances (RoHS) and Waste Electrical and Electronics Equipment (WEEE). RoHS requires manufacturers of electronic and electrical equipment to demonstrate that their products contain only minimal levels of lead, mercury, cadmium, hexavalent chromium, polybrominated biphenyl and polybrominated diphenyl ether. Waste Electrical and Electronics Equipment (WEEE) is and EU directive that is designed to encourage the reuse, recycling and recovery of electrical and electronic equipment. WEEE establishes requirements and criteria for the collection, treatment, recycling and recovery of such devices. WEEE also makes producers responsible for financing these activities, and requires retailers and distributors to provide a way for consumers to return used or obsolete equipment at no charge.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes On Digital Resistance Meters.
Digital resistance meters are instruments that measure electrical resistance. They use solid-state components and display values digitally. Resistance, which is measured in ohms, is the opposition to the flow of electric current of a conductor. Typically, digital resistance meters are powered by an internal battery that applies a small voltage to the circuit being tested. The positive lead is connected to the circuits positive side and the negative lead is connected to the circuits ground. The current is then measured and the resistance calculated. Zero resistance indicates a short. Infinite resistance indicates an open. Often, resistance readings that exceed product specifications are caused by a faulty component or problems such as burnt contacts, corroded terminals, or loose connections. To maintain accuracy, digital resistance meters require regular calibration that consists of connecting the two leads together and zeroing the meter with the adjustment knob.
Digital resistance meters typically display between three and seven digits along with a leading number such as 0 or 1. Four-wire systems minimize voltage drops in the test leads and record highly accurate measurements. Some digital resistance meters are used to monitor devices such as resistance temperature detectors (RTDs) or thermocouples. Others are used to monitor electronic components such as transistors or diodes. Benchtop, rack mounted, and handheld devices are commonly available. Battery powered units do not require plug-in power. Digital resistance meters with audibility continuity beep when the probes touch. Devices with analog bar graph capabilities display status readings such as battery power, signal level, and continuity.
Digital resistance meters interface to computers and include integral monitoring software for applications such as data acquisition. Programmable digital resistance meters allow users to set values that trigger monitoring routines. Data storage, logging, and removable data storage devices are often available. Some digital resistance meters allow users to adjust the sampling rate or provide internal memory. Others include an auto-ranging feature that automatically adjusts the measurement range. Output options include general-purpose interface bus (GPIB), binary coded decimal (BCD), and digital-to-analog (DA). RS232 is a standard communication protocol for serial ports. IEEE 488 is a standard communication protocol for parallel ports.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Digital resistance meters typically display between three and seven digits along with a leading number such as 0 or 1. Four-wire systems minimize voltage drops in the test leads and record highly accurate measurements. Some digital resistance meters are used to monitor devices such as resistance temperature detectors (RTDs) or thermocouples. Others are used to monitor electronic components such as transistors or diodes. Benchtop, rack mounted, and handheld devices are commonly available. Battery powered units do not require plug-in power. Digital resistance meters with audibility continuity beep when the probes touch. Devices with analog bar graph capabilities display status readings such as battery power, signal level, and continuity.
Digital resistance meters interface to computers and include integral monitoring software for applications such as data acquisition. Programmable digital resistance meters allow users to set values that trigger monitoring routines. Data storage, logging, and removable data storage devices are often available. Some digital resistance meters allow users to adjust the sampling rate or provide internal memory. Others include an auto-ranging feature that automatically adjusts the measurement range. Output options include general-purpose interface bus (GPIB), binary coded decimal (BCD), and digital-to-analog (DA). RS232 is a standard communication protocol for serial ports. IEEE 488 is a standard communication protocol for parallel ports.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on Milliohm Meters.
Milliohm meters are capable of measuring very small resistances. Devices which use a four-wire Kelvin probe system pass a test current through the probe so that the voltage is sensed by the center pin. This test method eliminates contact resistance and minimizes the possibility of errors caused by the resistance of the leads. By definition, resistance or impedance is a measure of the degree to which a material or device opposes the flow of current. This value is equal to the voltage drop across the element divided by the current through the element. As their name suggests, milliohm meters measure resistance in milliohms, a unit of measure which equals 1/1000 of an ohm.
Milliohm meters carry specifications for bandwidth, sampling rate, maximum channels, and operating temperature, as well as display type and display digits. Bandwidth is the frequency range for AC current or voltage to be measured. Sampling rate is the frequency that a digital meter tests an analog signal and converts it to a digital value. Maximum channels are the total number of channels for the device. Operating temperature is the full required range of temperatures over which milliohm meters operate. There are two choices for display type: analog and digital. Analog devices usually display values with a needle. Digital devices have an electronic display. For milliohm meters, the number of display digits ranges from 3 to 7 or more. Devices that can display a half-digit are also available.
Milliohm meters are available in several different form factors. Benchtop meters are designed to sit atop a bench or table. Free-standing devices have a full case or cabinet and an integral interface. Milliohm meters that function as clamp meters measure current through wires that are connected to the circuit. Rack-mounted devices include hardware such as rail guides, flanges and tabs. Handheld milliohm meters are relatively lightweight and can be operated while held in the hand. Devices with a computer-board form factor are printed circuit boards (PCBs) that plug into motherboards or backplanes. Milliohm meters with other form factors are also available.
Standards, options and features are important parameters to consider when specifying milliohm meters. Some products have an adjustable sampling rate, alarm lights, auto-ranging capabilities, and integral application software. Others feature data acquisition, data storage or logging, decibel reading, and external triggering capabilities. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated. Mirrored scales facilitate readings to a given accuracy and help operators avoid parallax errors. Range switches can be used to select the range of units to measure. Milliohm meters with overload protection, filters, scaling functions, and temperature compensation are also available.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Milliohm meters carry specifications for bandwidth, sampling rate, maximum channels, and operating temperature, as well as display type and display digits. Bandwidth is the frequency range for AC current or voltage to be measured. Sampling rate is the frequency that a digital meter tests an analog signal and converts it to a digital value. Maximum channels are the total number of channels for the device. Operating temperature is the full required range of temperatures over which milliohm meters operate. There are two choices for display type: analog and digital. Analog devices usually display values with a needle. Digital devices have an electronic display. For milliohm meters, the number of display digits ranges from 3 to 7 or more. Devices that can display a half-digit are also available.
Milliohm meters are available in several different form factors. Benchtop meters are designed to sit atop a bench or table. Free-standing devices have a full case or cabinet and an integral interface. Milliohm meters that function as clamp meters measure current through wires that are connected to the circuit. Rack-mounted devices include hardware such as rail guides, flanges and tabs. Handheld milliohm meters are relatively lightweight and can be operated while held in the hand. Devices with a computer-board form factor are printed circuit boards (PCBs) that plug into motherboards or backplanes. Milliohm meters with other form factors are also available.
Standards, options and features are important parameters to consider when specifying milliohm meters. Some products have an adjustable sampling rate, alarm lights, auto-ranging capabilities, and integral application software. Others feature data acquisition, data storage or logging, decibel reading, and external triggering capabilities. External shunts can be used to extend the current input range. Integrating functions allow the active power and current to be integrated. Mirrored scales facilitate readings to a given accuracy and help operators avoid parallax errors. Range switches can be used to select the range of units to measure. Milliohm meters with overload protection, filters, scaling functions, and temperature compensation are also available.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Application Notes on AC Clamp Meters.
AC Leakage clamp meters are capable of reading extremely low currents which could be leakage current to earth or another return route.
Clamp meters are ammeters that can measure current without the need to disconnect the wires where the measurement occurs. They provide information about current draw and current continuity in order to help users troubleshoot erratic loads and trends. Clamp meters have both positive and negative leads and feature extremely low internal resistance. They are connected in series with a circuit so that current flow passes through the meter. High current flow may indicate a short circuit, an unintentional ground, or a defective component. Low current flow may indicate high resistance or poor current flow within the circuit.
There are two basic types of clamp meters: digital and analog. Both are designed to measure levels of alternating current (AC) and direct current (DC). Some clamp meters that measure AC current also measure root mean square (RMS) power, which is the square root of the time average of the square of the instantaneous power. Most products include a current sensor built into the clamp around the wire. Different types of clamp meters can measure different ranges of AC current, DC current, and AC current frequency. Some clamp meters are handheld and portable. Others are designed for benchtop or shop floor use. Battery-powered clamp meters can be operated without plug-in power and may be rated for outdoor use.
Clamp meters may provide special measurement types or optional features. Some clamp meters can test diodes or transistors. Others can monitor thermocouples or resistance temperature detector (RTD) values. Programmable clamp meters provide internal data storage and allow users to establish activation triggers. They can also interface with computer hardware and software. In addition, products with external storage devices such as disc drives are available. With regard to optional features, clamp meters may adjust sampling rates automatically, display status information as a bar graph, and measure decibel (dB) readings. Mirrored scales make it easier to read clamp meters to a given accuracy by enabling operators to avoid parallax errors.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
Clamp meters are ammeters that can measure current without the need to disconnect the wires where the measurement occurs. They provide information about current draw and current continuity in order to help users troubleshoot erratic loads and trends. Clamp meters have both positive and negative leads and feature extremely low internal resistance. They are connected in series with a circuit so that current flow passes through the meter. High current flow may indicate a short circuit, an unintentional ground, or a defective component. Low current flow may indicate high resistance or poor current flow within the circuit.
There are two basic types of clamp meters: digital and analog. Both are designed to measure levels of alternating current (AC) and direct current (DC). Some clamp meters that measure AC current also measure root mean square (RMS) power, which is the square root of the time average of the square of the instantaneous power. Most products include a current sensor built into the clamp around the wire. Different types of clamp meters can measure different ranges of AC current, DC current, and AC current frequency. Some clamp meters are handheld and portable. Others are designed for benchtop or shop floor use. Battery-powered clamp meters can be operated without plug-in power and may be rated for outdoor use.
Clamp meters may provide special measurement types or optional features. Some clamp meters can test diodes or transistors. Others can monitor thermocouples or resistance temperature detector (RTD) values. Programmable clamp meters provide internal data storage and allow users to establish activation triggers. They can also interface with computer hardware and software. In addition, products with external storage devices such as disc drives are available. With regard to optional features, clamp meters may adjust sampling rates automatically, display status information as a bar graph, and measure decibel (dB) readings. Mirrored scales make it easier to read clamp meters to a given accuracy by enabling operators to avoid parallax errors.
Sebastian
G.M. Technical
Nunes Instruments
645 Hundred Feet Road,
Coimbatore. 641012.
Tamil Nadu
India,
Web: www.nunesinstruments.com
Web: www.nunesinstruments.asia
Mail: info@nunesinstruments.com
Mobile: 09345226022
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