Transformer Oil BDV (Breakdown Voltage) Testers are widely used in high-voltage electrical equipment such as transformers, oil circuit breakers, oil-filled cables, power capacitors, and oil bushings. During operation, the performance of the oil will gradually deteriorate due to the effects of oxygen, high temperature, high humidity, sunlight, strong electric fields, and impurities, so that it cannot fully function as an insulator. To identify whether its performance has deteriorated, the quality of insulation oil is closely related to the breakdown voltage.