Influence of ultrasonic homogenization on particle counts and dielectric strength of transformer oil

Particle deposition occurs very rapidly and it modifies significantly the breakdown voltage and the metals content of transformer oil. This leads to unrealistic values not representative of the oil's condition in the transformer. It has been shown that particles in oil homogenization can be successfully achieved by 25 min of ultrasonic agitation for a I-liter volume of oil. This simple, rapid and inexpensive procedure should be applied to any liquid sample before particle counting, dielectric strength and metals content measurements.