Hundreds of thousands of thermistors 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, Hart’s Secondary Reference Series thermistor probes are the best you can buy.

A thermistor offers several advantages over a PRT as a reference thermometer in some applications. First, there’s size. A thermistor is much smaller than a PRT element, and so it can be built into a much larger variety of probe shapes and sizes. The smaller element contributes to much faster response times, too. 

If your application involves frequent handling, a thermistor is less susceptible to mechanical shock than a PRT. The bottom line may be better accuracy in fieldwork. 

Higher base resistance and larger resistance coefficients make it easier to achieve precision readings. Better resolution and accuracy are possible for a lower cost. 

These probes come in a complete assembly ready for use, and they make an excellent match with the uncertainties of our thermometer readouts: the 1504 Tweener, the 1521 and 1522 Handheld Thermometers, the 1529 Chub-E4, the 1560 Black Stack, and the 1575A and 1590 Super-Thermometers. 

These probes are accurate to ±0.015°C, and each comes with a NIST-traceable calibration and a resistance versus temperature table printed in 0.1°C increments. 

The Secondary Reference Series Thermistors cover the temperature range of 0°C to 100°C. No other sensors can match the accuracy and price combination of these high-accuracy thermistor probes. Try one and you’ll agree.