1. The first spark discharge voltage is very low. The first test may be influenced by some external factors when the oil sample is injected into the oil cup or the surface of the oil cup electrode is dirty before oil filling, which makes the first value low. . At this time, the average value of 2-6 times can be taken.
2. The value of the 6th spark discharge voltage gradually increases, which generally occurs in oil samples that have not been purified or treated enough and absorb moisture. This is because the oil is sparked. The moisture level of the oil is improved.
3. The value of the spark discharge voltage gradually decreases for 6 times. It usually appears in the purer oil in the test, because the generated free charged particles, bubbles and carbon chips increase successively, which damages the insulation performance of the oil. In addition, some automatic oil testers do not stir in 6 consecutive tests. The carbon particles gradually increased, resulting in a gradual decrease in the spark discharge voltage.
4. The spark discharge voltage value is low at both ends and high in the middle. This is normal.
5. Due to the large dispersion of the oil withstand voltage test results, if the breakdown voltage is too high (close to 80KV) each time or the results are the same each time, it means that the instrument may be damaged, please contact the manufacturer.
6. If there is a large dispersion of the withstand voltage value, such as: in the test carried out according to the preventive test method, one of the six tests has a value that deviates from other values a lot. The large dispersion may be caused by poor oil quality or uneven distribution of free carbon.