Temperature Sensor FAQs

How often should I recalibrate the sensor?

We recommend verifying calibration every two years. The Apogee ST-100 and ST-200 temperature sensors are not factory calibrated, but come with a generic calibration (see the Operation and Measurement section of the owner's manual). A custom calibration can be derived by comparing the temperature from the thermistor to a reference temperature measurement. Often, a simple offset can be used to make measured temperature match reference temperature.

Does the ST-100 have NIST traceability?

All thermistors are measured for accuracy in specially designed constant temperature baths that are directly traceable to the National Institute of Standards and Technology (NIST). The overall measurement system uncertainty or all the bath and measurement allowances combined for error is typically less than 0.01 C and completely traceable to National Standards.

How accurate are Apogee temperature sensors?

Measurement Uncertainty

ST-100	ST-110	ST-200	ST-300
0.1 C (from 0 to 70 C)	0.1 C (from 0 to 70 C)	0.2 C (from 0 to 70 C)	0.1 C (from -40 to 60 C)
0.2 C (from -25 to 70 C)	0.15 C (from -35 to 0 C)	0.4 C (from -50 to 0 C)
0.4 C (from -50 to -25 C)

Can I use the temperature sensor with a voltmeter?

Yes with a voltmeter that measures resistance. Once you measure the resistance across the thermistor, that resistance corresponds to a temperature a table with the corresponding temperatures and resistance can be found here. The correct thermistor wires to measure on the ST-100, ST-110 and ST-200 are red and black.