https://www.mktester.com/transformer-oil-tester/transformer-oil-dielectric-strength-tester.html
Many power systems, railway systems, large-scale petrochemical plants and enterprises have a lot of electrical equipment whose internal insulation are mostly oil-filled insulation type, and therefore, test on insulating oil dielectric strength is common and necessary. To meet the needs of the market, we have developed and produced a series of insulating oil dielectric strength testers according to national standard GB/T507-2002, industry standard DL429.9-91 and the latest Electric Power Industry Standard DL/T846.7-2004 by ourselves. This instrument, by using a single-chip microcomputer as the core, can operate in full automation with high accuracy, greatly improving work efficiency and reducing the labor intensity of workers. Moreover, it is sall in size and convenient to carry.