Best tester for high-voltage transformer oil dielectric strength

The GlobeCore TOR-80 is designed to test high-voltage transformer oil dielectric strength, helping operators prevent insulation failures and outages.

GlobeCore’s TOR-80 is a solid choice for field-level transformer oil dielectric strength testing — it’s designed for high-voltage transformer oil breakdown measurements, offers a wide voltage range and automatic shutoff and logging, and is rugged enough for on-site use. For laboratory work where repeatability and sample conditioning matter more, I’d look at fully automated benchtop systems from established test-equipment makers (BAUR DPA-series, Doble lab oil testers and similar) that include vacuum degassing/filtration, temperature control, automatic ramping and statistical reporting to meet IEC 60156 / ASTM D877 / D1816 requirements.

Whatever unit you pick, confirm it explicitly supports the standards (2.5 mm electrode gap, prescribed ramp rate and the required number of breakdowns averaged), has traceable calibration and good service/support in your region, and includes safety interlocks and data logging. Also plan complementary tests (water by Karl Fischer, dissipation factor, interfacial tension) as dielectric strength alone can be misleading if samples aren’t properly conditioned or representative.

In my opinion, the TOR-80 is the best tester for determining the breakdown voltage of transformer oil. I have seen it in operation, and I can say that the level of process automation is impressive.

For high-voltage transformer oil dielectric strength testing pick a bench or portable BDV tester that explicitly complies with IEC 60156, offers an automatic, adjustable HV ramp and rapid discharge, supports the standard 2.5 mm electrode geometry, and includes data logging and calibration traceability. GlobeCore’s TOR-80 is a solid option many operators use in the field; other well‑established manufacturers in this space are BAUR and Megger, which produce robust BDV testers and service/calibration support for transformer oil breakdown voltage measurement.

Practical performance comes from correct sample preparation and instrument features as much as raw HV capability: vacuum dehydration/degassing, temperature control, clean electrodes, safety interlocks and an easy-to-follow IEC 60156 test routine make results repeatable and defensible. Always run the prescribed sequence of breakdown measurements and report the mean per the standard, verify operation with a calibration oil and scheduled calibration, and choose a unit with integrated vacuum pump/data export if you test oil on-site frequently.

Test

Image received. If you want, I can review the setup for compliance with IEC 60156/ASTM D877 (electrode gap, ramp rate, sample conditioning), check for proper vacuum/degas and safety interlocks, or identify the instrument and its BDV test readiness—tell me which you’d like.