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How to Test a Micro-Ampere Meter

The electrical flow of charged particles is known as electricity. Electrical current is measured in amperes and is a measure of the speed charged particles flow. Most everyday appliances work with relatively large currents of a few amps. More sensitive electrical apparatus such as those in scientific experiments produce only tiny currents. In order to measure such tiny currents, a specialized device known as a micro-ampere meter is needed. These devices normally consist of a series of inputs, buttons to control the range of measurements and a screen to output the result.

Things You'll Need

Micro-ampere Meter
Voltage supply
10MOhm resistor

Instructions

- 1
  Connect the positive and negative terminals of the power supply to the either side of the resistor. The polarity of the connection is not important in this case.
- 2
  Connect the micro-ampere meter measurement leads to either side of the resistor. Again the polarity is not important since it is the magnitude of the current that is being measured.
- 3
  Switch on the power supply, and set a DC voltage of approximately 1V.
- 4
  Switch on the meter. Most micro-amp meters are auto-ranging, but some will also have a range button. If a manual range setting is required, set a range that is capable of measuring 1 micro-amp.
- 5
  Read off the measured value of current. Using Ohm's law, the expected current can be calculated:
  
  Current = Voltage / Resistance = 1 V / 1000000 Ohms = 1 micro amp.
  
  The display should read 1 micro-amp, and this demonstrates that the micro-ampere meter
  
  is working within its specified measurement range.

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