A Thermal Method of Standardizing Dielectric Power Loss Measuring Equipment

After a brief review of the need for reference standards in dielectric power-loss measurements at high voltage and commercial power frequencies, this paper describes a thermal method for measuring dielectric power loss in cable, utilizing the sheath temperature rise associated with the flow of heat due to the power loss within the sheath. Sources of error are discussed briefly, and results are given in comparison with measurements of dielectric power loss by the reflecting astatic electrodynamometer wattmeter using an air capacitor for phase-angle compensation. In connection with the investigation, certain possible errors in dynamometer measurements are noted, particularly the effect of humidity on power loss in the air capacitor.