Assurance of induction system working in compliance with operating practices
requires known of its parameters, including electrical one. Unfortunately powerful high
frequency power supplies are not completing regular devises for measurement of inductor
current, voltage and power factor. Design philosophy and important characteristics of sensors
for measure of voltage up to 10 kV and current up to 400 A at frequency 1.7 – 1.9 MHz are
describes in the paper. Principles of calibration of the sensors are presented too. For definition
of power factor of induction system is used two methods. One of them is based on measuring
of phase angle between inductor current and voltage. Second one in based on measuring of
inductor active and total power. Results of measuring of power factor of induction system
with cold crucible at single mode and during melting of aluminum oxide are presented.