Ultrasonic-based measurement of pre-treated insulating oil samples at defined humidity and temperature levels

Within the framework of the AiF research project (Industrial Cooperative Research Associations) ultrasonic measurements of various pre-treated insulating oil samples are carried out in a frequency spectrum of 2 - 6 MHz. The aim of this work is to investigate the potential of ultrasonic technology as a detection/monitoring method in the field of insulating oils of high voltage transformers. The main focus of the investigation is on insulating oil samples with defined moisture contents. Additional environmental influences such as temperature and pressure are considered during the measurement. The subject of this publication are findings from the moisture measurements. The results of the ultrasonic measurements are presented as sound velocity, amplitude (time and frequency range), peak frequency and other evaluation parameters in relation to the moisture and temperature level.