Abstract: A system for calibrating an energy meter is provided. The energy meter has a rotor which rotates at an angular velocity generally proportional to the energy input to the meter. A reference transducer receives an energy input for generating a reference signal having a predetermined parameter, such as frequency, generally proportional to the energy input. A test apparatus is responsive to rotation of the rotor to generate a test signal having a predetermined parameter, such as frequency, generally proportional to the angular velocity of the rotor. An error signal generator receives the reference signal and the test signal upon fractional rotation of the rotor and generates an error signal to indicate the amount of error between the frequency of the test signal and a calibration value corresponding to the frequency of the reference signal. The meter is calibrated based on the error signal. A related method is also disclosed for calibrating the meter.

Abstract: An electrical test switch having a pair of spaced conductive rotors provided with matching cut-outs, the rotors being movable between a "normal" position and a "test" position. At least two spaced conductive contacts extend within a region between the rotors. The cut-outs and the conductive contacts are arranged so that the contacts wipe against the rotors when the rotors are in the "normal" position and at least one of the spaced contacts is aligned with the cut-outs when the rotors are in the "test" position. A shaft locks the switch in the "normal" position until manually released.