Hello All,

 

I got two NIST traceable thermometers in today one reading 21.0 C and the other 20.1 C. they are both perfectly acceptable according to manufacture specifications. If I happen to run into an incoming shippment of platelets that  reads 20.2 C on the 1st and 19.3 C on the 2nd, will  my 2nd thermometer render my platelet shipment unacceptable? When I used to calibrate glass thermometers to the NIST, I would label it to reflect adding or subtracting 1 degree if the reading was off  by 1 degree, in order to match the NIST. I was wondering if that can be done with the electronic thermometers; they provide a certificate with the NIST reading and with the instrument reading at the time of calibration.

I need one of the thermometers for my incubator and I suspect the same thing can happen there. If the actual temp is 37, but my reading is 36.1. Since my range is + 1, I can see it  being a problem if my actual temp is 36.2 per say, and my thermometer is reading 35.3. Technically I'm within range according to the reference thermomether, but out of range with the instrument.

 

Any input on this?

You can get thermometers with a smaller tolerance or have them calibrated to the tolerance you need. They usually come with a calibration certificate that is valid for 2 years - I have found it is usually cheaper to replace the thermometer than get it recalibrated when the two years are up.

We always check the specs before we purchase any electronic thermometers and pick the ones with the tighest tolerances.  Some of them specify +/- 2C... definitely not accpetable for our needs.  We want all of our Blood Bank thermometers to be within 0.5 of the reference thermometer.  We verify on receipt for the temperature ranges in which they will be used and annually thereafter.