Abstract

Space Dynamics Laboratory (SDL) has observed, over several years of work with various blackbodies, significant unexplained calibration drifts in the small industrial temperature sensors used in these blackbodies. These variations can exceed the sensor specifications reported by the manufacturer. With a mandate to build more accurate calibration sources with tens of milliKelvin accuracy, SDL began an effort to understand the calibration drifts in these temperature sensors. The primary testing involved repeatedly cycling PRTs and thermistors from a variety of manufacturers through a range of temperatures in a thermal bath. The bath temperature was measured with a secondary standard PRT probe. Batches of identical sensors were tested to determine variation between individual sensors of the same type. Additional results were obtained once well-performing tested sensors were placed in a blackbody. A key test result is that temperature sensors readings drift during thermal cycling with some models generally performing better than others but there can be significant variation among individual sensors of a given model. Additional results include observed changes in sensors when placed in a mounting fixture, sensitivity of some PRTs to handling, and very good performance from one thermistor model.

Share

COinS
 
Aug 28th, 9:50 AM

Characterization of Small Industrial Temperature Sensors

Space Dynamics Laboratory (SDL) has observed, over several years of work with various blackbodies, significant unexplained calibration drifts in the small industrial temperature sensors used in these blackbodies. These variations can exceed the sensor specifications reported by the manufacturer. With a mandate to build more accurate calibration sources with tens of milliKelvin accuracy, SDL began an effort to understand the calibration drifts in these temperature sensors. The primary testing involved repeatedly cycling PRTs and thermistors from a variety of manufacturers through a range of temperatures in a thermal bath. The bath temperature was measured with a secondary standard PRT probe. Batches of identical sensors were tested to determine variation between individual sensors of the same type. Additional results were obtained once well-performing tested sensors were placed in a blackbody. A key test result is that temperature sensors readings drift during thermal cycling with some models generally performing better than others but there can be significant variation among individual sensors of a given model. Additional results include observed changes in sensors when placed in a mounting fixture, sensitivity of some PRTs to handling, and very good performance from one thermistor model.