I would like to know how everyone is validating thermometer accuracy. In the AABB technical manual, the procedure describes "recreating" the desired temperature in a beaker. Does anyone place a NIST certified thermometer in the fridge/freezer for a determined amount of time and compare the two temperatures?

I don't know how to recreate -30 C!

I can't do -30 . . . what I do is -20 when I do my alarm checks.

We have a calibrated digital thermometer. If you don't have one I bet you could borrow one from your clinical engineering dept. I stick the probe in the bottle with the thermometer probe of the FFP freezer, shut the door on the cord and give it a few minutes to let it equilibrate to -29-30o.

Pre-calibrated digital thermometers is what we use. And I have found it's cheaper to replace them than to send them off for calibration when it is due...

We do that too.

Where do you get your pre-calibrated digital thermometers? Actually most of our refrigerators and BB equipment has Isensix monitors so I don't have to worry about them. But there are still a couple left. And no one knows when our $3000(!) NIST thermometer was last calibrated!

The companies who supply your 'stuff' like test tubes, pipettes, etc etc will have the thermometers most likely. I order mine from Cardinal. Fisher has them. ML has them. Lots of choices, so if you aren't locked into buying from a specific vendor, you can shop for the best price.

We're tied to Fischer