Summary
  The instrument is a new instrument specially developed for resistivity determination using the active bridge principle as per industrial standard of People’s Republic of China DL/T421-91 Standard Test Method for Volume Resistivity of Insulating Oils. It has characteristics of simple structure, excellent linearity, high sensitivity, stability, and safety. It is better than the instrument using voltage and current method.

I. Main technical features
1. The instrument is composed of parameters measurement system and oil cup heating control system. Its measurement
    range is 10 8 ～19.99×10 13 Ω•cm. It can time, read readings and save test data automatically.
2. Simple structure. Good linearity and linearity. Stable test result. Safe to operate.  
3. Excepting to determine the volume resistivity of insulating oils, it can also used to determine resistivity of transformer oil and
    lubricating oils. It is the best choice to determine volume resistivity of lubricating oils in the power industry, petroleum
    industry, scientific research institutes, and relative factories and companies.

II. Main technical specifications
1. Measuring voltage: 500V, DC
2. Measuring range: 10 8 ～19.99×10 13  Ω•cm
3. Repeatability: ＞1012 Ω•cm ≯25%；   ＜1012 Ω•cm ≯15%
4. Temperature control power: 300W
5. Temperature control range:  30～100℃
6. Temperature control accuracy: ±0.5℃
7. Measuring bias: ≤±10%
8. Electrode cup: 3 pieces
9. Ambient temperature: 0～40℃
10.Relative humidity: ≤85%
11.Power supply: AC 220V±10%, 50Hz±1Hz