These are our findings as to the pros and cons of electronic temperature probes.

Thermocouple Probes. Stable, have a large inaccuracy, but are not susceptible to physical shock.

RTD, SPRTD,PRTD. Very accurate, but susceptible to physical shock which can put them out of calibration. Used at NIST and most calibration labs. Good when handled with care.

Thermistors. Very accurate but have a limited temperature range and are not susceptible to physical shock.

Edited June 8, 200916 yr by JohnD

Very useful info- thanks!

My problem is always "how accurate is accurate enough?"

In Blood Banking, the standards read in integers, so we'd like to verify with something to the next decimal point (+ 0.1 C). However, when you start looking into LIG, infrared and electronic thermometers for bench use, you find that the accuracy does not approach 0.1 C, esp with most LIG thermometers that come with "certificates of accuracy".

And we haven't even discussed other measurement variances yet ...

It almost seems like most of what we do is a low-leveraged activiy of borderline utility, done only to show an inspector that we're doing something!

I agree with you about the inspector, however +/- 1C seems a little excessive for Blood Bank.

Hi All,

Just reading the thread the only probe you can use, and with ABB's experience we were easily able to research this, you need to use Class "A" Pt 100 probes with a +/- to 50c range, they are the only probe's accurate to 1/2 a degree, which is the required standard in the UK to MHRA expectations, we looked at various loggers etc, and felt this was the best way forward for mapping and Calibration of the Blood fridges.