Originally Posted by RajunCajun
... Do I just have crappy thermometers and need to upgrade, or am I doing this wrong? ...
You are doing it right - Your thermometers are bad.
A decent thermometer should be capable of being adjusted at either freezing or boiling, and properly indicate the other extreme without further adjustment. Back in my fast food days, we started with the probe tips in boiling water, and then moved each thermometer, one at a time, into an ice-water bath. In addition to checking/adjusting for the right temperature, it was also important to note how smoothly the pointer went from one extreme to another.
If there was jerkiness, or the needle seem to hang at any temperature during it's travel, the temperature of the garbage can was then measured for an indefinite period of time...