5610 / 5611 / 5611T Temperature Probes, Reference Thermistor Probes

Hundreds of thousands of thermistors and temperature probes are sold every year, but only a few have the stability necessary for use as high-accuracy thermometry standards. If you're looking for economical lab-grade thermistor probes for accurate work across a narrow temperature range, Fluke Calibration Secondary Reference Series thermistor probes are the best you can buy.

These temperature probes are available in a variety of sheath materials appropriate for your specific application. In addition to our metal-sheathed temperature probes, we offer flexible PTFE encapsulated and silicone coated thermistors that have smaller tips and can measure those places where even a metal-sheathed thermistor can't reach.

All Fluke Calibration secondary reference thermistors have small diameters and very small sensing elements, which means they require far less immersion than a PRT to avoid errors caused by stem effect. Self heating is usually negligible, giving them an advantage when taking measurements in air. Their small size also improves response time, allowing measurements to be taken more quickly.

If your application involves frequent handling, you'll be especially interested to know thermistors are less susceptible to mechanical shock than PRTs. The bottom line may be better accuracy in fieldwork.

Additionally, higher base resistance and larger resistance coefficients make it easier to achieve precision readings with thermistors, so better resolution and accuracy are possible for a lower cost. All of these thermistors have a negative temperature coefficient of resistance (NTC).

What's more, the Secondary Reference Series Thermistors are accurate to +/- 0.01 °C and cover the temperature range of 0°C - 100°C. They come with a NIST-traceable calibration and a resistance-versus-temperature table printed in 0.1°C increments that can be interpolated to 0.0001 °C. NVLAP accredited calibrations as single thermistors or as systems combined with their readouts, are also available.

These probes come in a complete assembly ready for use, and each works well with the uncertainties of our thermometer readouts: the 1504 Tweener, the 1523 and 1524 Handheld Thermometers, the 1529 Chub-E4, the 1560 Black Stack, and the 1575A and 1590 Super-Thermometers.  These probes provide most accurate readings when coupled with a 2563 Standards Thermistor Module or 1590 Super-Thermometer, but they are most portable when used with a handheld reference thermometer.