Patent ID: 7612552

Claim:
A method of metering an electrical characteristic of a system, comprising in the following order: a) providing an electrical phase checking apparatus, the electrical phase checking apparatus comprising: a first voltage sensor; a first current sensor; a first binary indicator connected to said first voltage sensor and first current sensor, said first binary indicator configured to indicate when a phase separation between a voltage waveform measured by said first voltage sensor and a current waveform measured by said first current sensor is not more than a first value; a second voltage sensor; a second current sensor; and a second binary indicator connected to said second voltage sensor and second current sensor, said second binary indicator configured to indicate when a phase separation between a voltage waveform measured by said second voltage sensor and a current waveform measured by said second current sensor is not more than a second value, wherein the apparatus further comprises a first voltage probe connected to the first voltage sensor, a first current probe connected to the first current sensor, a second voltage probe connected to the second voltage sensor, and a second current probe connected to the second current sensor; b) attaching at least two of said probes to at least one wire in said system; c) reading a binary indication output by at least one of said binary indicators; and d) detaching at least one of said at least two of said probes and attaching it to a different wire in said system in response to said reading.