Oil resistors provide better stability and temperature coefficients over air resistors and provide the highest precision and stability in resistance measurements.
Our high-accuracy primary standard (model 9331R) air resistors are used for precision resistance calibrations for values from 0.1 Ω to 10 MΩ with drifts up to 2.5 ppm per year drift.
Our high-accuracy working standard air resistors are used for precision resistance calibrations for values from 1 mΩ to 100 MΩ. MI’s 9331’s are small, light, and rugged resistance standards that do not require a temperature-controlled oil or air bath for their specification range. The 9331 series features an A version (up to 10 ppm yearly drift) and a B version (up to 5 ppm yearly drift) for operation in any working environment within the range of 18 °C to 28 °C.
The 9331G series of high accuracy resistance standards are available in standard values from 10M to 100T Ohms and custom values available at any resistance therein.