Abstract :
It is the intention to consider only the application of the current transformer to and its effect upon electrical measuring instruments, particularly the instruments whose operation depends not only upon definite magnetic fields, but also the phase-angle between them. These instruments include wattmeters, watt-hour meters, power-factor meters, etc., but only the two former will be considered here. The measurement of alternating volts, amperes, and watts, has been and is now, a most vital one, at least so far as ordinary commercial measurements are concerned.
