The Voltmeter is a piece of equipment that can be used to check the voltage and the current passing through a wire.
If you right click on a piece of Blue Alloy Wire or a RedPower2 Machine (as they also act as wires), it tells you the voltage and current reading in Volts and Amperes. Small fluctuations in the readings are normal, these happen as the system attempts to reach an equilibrium.
Note that the voltmeter does not work on things like Nuclear reactors or Cables, because these are part of IndustrialCraft. The EU-Reader is the correct tool to use with these blocks.
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