Instruments to measure the salient properties of fluid dielectrics

A range of compact portable instruments has been developed to diagnose and quantify changes in fluid dielectrics in order to maintain them in a satisfactory condition. The degree of moisture saturation (RH) of a liquid dielectric can be used to assess its condition and that of the associated solid insulation and the RH meter measures this value directly. The Karl Fischer instrument measures the actual quantity of water present in parts per million and the Oxidation meter determines the degree of thermal aging of the fluid that has occurred. Any gasses evolved by the dielectric due to hot spots, arcing or partial discharges can be identified and quantified by using the gas analyser unit.