C
I don't understand. If the temperature in the freezer goes to... 60°F, what impact does that have on your materials? I would think at some point the temperature affects the materials.
60°F. If we have power outages, the room temp. is affected but at this very short period of time, the materials are still ok. Now if the problem takes weeks before fixing it, the consequence is that we have to double the amount of material that we normally use. Kinda complicated.
I can't imagine it being too expensive. There are lots of good calibration houses, and for the accuracy you would have on such a device, I wouldn't think it too much at all.

So as a corrective action, I will buy one