An ohmmeter is an instrument used to measure the electrical resistance of a conductor. In normal usage, the ohmmeter operates by using the voltmeter to measure a voltage drop, then converting this reading into a corresponding resistance reading through Ohm's law. If the current is known, the voltage drop across the unknown resistance may be read to give the resistance directly. If the current is not known, or if it is not possible to measure the voltage across the unknown directly, reading the voltage drop across a known resistance in the same circuit will give the current, and once this voltage is subtracted from the total drop for the circuit, the voltage drop across the unknown, and thus its resistance, may be found, and displayed on the ohmmeter. A micro-ohmmeter is an ohmmeter for the measurements of very low resistances.
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Type |
Features |
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High accuracy Megohmmeter |
1 kΩ -100 TΩ; 0.5% |
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High accuracy Micro-Ohmmeter
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High Performance Micro-Ohmmeter
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Portable Digital Micro-Ohmmeter, Rugged |
1 μΩ -600Ω; 10 A; Autoranging |
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Low Resistance Micro-Ohmmeter, Rugged |
0.1 μΩ -60Ω; 10 A; Autoranging |
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Portable Digital Ohmmeter Miicro-Ohmmeter |
10 μΩ-4kΩ; 0.05%; Autoranging |
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High Range Digital Micro-Ohmmeter |
0.1μΩ-30,000Ω; 0.03% |
The GenRad 1863 Megohmmeter is the choice for production and inspection tests. The 1863 will measure
resistance at any of five common test voltages up to 500VDC, has fewer controls, and is the lower priced model. It is the best selection for those applications requiring a lesser voltage and resistance range.
The GenRad 1864 Megohmmeter is the choice for more demanding applications. It is the more flexible of the two instruments. The test voltage can be set to any value from 10VDC to 109VDC in 1-volt steps and to 1090VDC in 10 volt steps. Thus the 1864 can be set to any common, or uncommon test votage for ceramic, mica or paper capacitors, or other devices. The reverse resistance of rectifiers can be readily measured; the low test voltages are especially useful in measuring solid state diodes. An additional range permits measurements up to 200TW (2 x 1014W)
LOM-510A Micro-Ohmmeter
The LOM-510A Micro-Ohmmeter has 4½ digits, 002% basic accuracy and 1 μΩ resolution. Its 4-terminal measurement technique eliminates lead resistance errors and 80 dB of ac noise rejection provides rock-steady readings even in noisy locations The micro-ohmmeter comes with rugged 4-terminal test clips and a large selection of optional probes, clips and fixtures allowing attachment to any low-resistance unknown.
The DO7e is a very rugged yet compact and portable digital microhmmeter for the measurem
ent of low resistance. Using a rechargeable sealed lead acid battery with built-in charger the DO7e Microhmmeter is capable of measuring with a current of 10Amps on the lowest range.The DO7e Microhmmeter has been designed with the latest solid state and microprocessor techniques to ensure the very best in measurement reliability, and features. Automatic range selection, forward and reverse current measurements with auto average and a remote start socket are all included as well as an energy saving power down mode
The series 4000 digital ohmmeters offer true portability without any sacrifice to accuracy or fun
ctionality. These ruggedly constructed ohmmeters are housed in a stylish plastic case with an easy to use keyboard, the measured values are displayed in large LCD panel. Many advanced measurement features are included, Long scale length 4000 count, Auto average of forward and reverse current measurement, true zero of measured value and temperature compensation (model 4001). Rechargeable batteries with automatic power off ensures the best possible battery performance.
