Re-calibrating Sensors

We are often asked how often sensors should be re-calibrated.  The answer to that simple question is complicated.  It depends, first, on what type of sensor it is.  For example, our digital sensors, which are used to monitor temperature in refrigerators and freezers will not get out of calibration for years.  Many of our customers also use 2di thermistor sensors for the same purpose and they can ‘drift’ over time, although not by much.  Our thermocouple sensors, on the other, hand do drift quite a bit depending on how they are used; what temperatures they are exposed to.

So the first thing to consider is what type of sensor it is and how it is being used.  The 2nd factor, and this is usually the overriding factor is who  the temperature is important to.  For example, some industry associations and regulatory bodies recommend that sensors be calibrated on a regular schedule of their own choosing.  The CDC suggests that thermometers used to monitor vaccine refrigerators and freezers e re-calibrated every year or according to the manufacturer’s recommendation.  Re-calibrating once a year is overkill since all of our sensors should remain in calibration for at least 2 years, but they have a lot of weight with the health care industry.

When we issue a Certificate of Calibration there is always a suggested re-calibration date.  Since we are the manufacturer of the sensors this is the manufacturers recommendation.