Hanna Instruments thermometer for the temperature inside a fridge or freezer, one model.
HI147
This Hanna Instruments thermometer measures the temperature inside a fridge or freezer, read from outside it.
Opening a door to read a thermometer is what warms the cabinet, so the act of checking corrupts the thing being checked. A sensor on a lead leaves the display outside, where it is read without touching the door.
Most wrong temperatures are not the instrument's fault. A probe placed too shallow, read before it settled, or put in the thinnest part of a piece of food gives a confident number that was never true of the product.
Insert to the depth marked, into the thickest part, and wait for the reading to stop moving. Check the instrument against an ice-water slurry periodically — that is a real reference point, and it costs nothing.
Place the sensor in the warmest part of the cabinet, not the coldest; the warmest point is what determines whether the contents are safe.
Supplied as one model.