Thermometer calibration

[NB883]

We currently send out our thrmometers for calibration. I would like to send 1 and calibrate the rest to it. I am not sure how to perform the calibration, does anyone know how many temps you need. Would it be just the range you need for your fridge or freezer?

[Likewine99]

You will need to have a certified NIST thermometer to use as your reference thermometer. I've always tested all thermometers in the dept across all temperatures, that is; freezer, refrig, RT and 37 degrees. That way when one breaks or quits working you have one ready to move into it's spot.

We did this twice a year, or whatever your accrediting agencies require. Then make up a log sheet, you can use an Excel spreadsheet if you like. Give each thermometer a number, label it, test it across all ranges, record the temps along with the reference thermometer reading and don't forget to list on your log sheet the tolerance limits.

I don't have access to our SOP's but this is the "easy button" as far as tasks in the BB.

[John C. Staley]

I discovered that it was cheaper and easier to just buy certified thermometers every 3 years than it was to try to buy a decent NIST certified thermometer and go through the hassel. When I retired the thermometers I gave them to the other sections of the laboratory and they were excited. If I remember right I got them from Strek.

:surrender

[Dr. Pepper]

We use 2 NIST-traceable digital thermometers. (Digitals have a wide range and are inexpensive and durable, unlike the old reference thermometers we used to have that lived in padded, gilded cases and were handled as gingerly as plutonium.) One has a small, wire probe that's very responsive and is quite handy used in some of the other lab areas as well. An outside company comes in yearly to recertify these, along with others from clinical engineering, tachometers etc. I just check the thermometers at the temperature of use for each, as we have different models for freezer, 1-6o and room temp. New thermometers should be checked before placing in use and at least yearly thereafter (CAP). Don't forget to check any digital readouts as well. AABB adds that electronic ones should be checked as specified by the manufacturer.

The AABB tech manual (17th edition, pp. 965-967), has a good procedure.

[Eagle Eye]

same as Dr. Pepper...We calibrate our thermometers annually and before placing in use(regardless of their certification from buyers). We also calibrate(mid point) our probes for our central temp. Monitoring system.

[AMcCord]

Same as Dr Pepper, though for the ultralow freezer we buy a new one as needed for not many $$$s.

[Auntie-D]

Same as john - its easier (and cheaper) just to replace them when the calibration certificates run out. We hand ours down to other departments too who are also always delighted.