How do I calibrate a thermometer?
I have a metal thermometer that I want to use in my darkroom. The temperature reading is off by about 20 degrees. Isn't there some way to adjust it by using a glass of ice water?
Tags: darkroom, temperature reading, thermometer
Filed under: Cooking Thermometers | Jan 26th, 2010.
Assuming that it is a stem thermometer, you use the hex nut at the back of the thermometer. Since Ice and ice water are at 32 degrees, you put the stem into the water, wait until the needle levels out, then adjust the needle to point to 32.
The thermometer itself is the stem and the needle at the top. The paper at the top, where the numbers are printed are just to clarify the reading relative to the user. Using the wrench to stabilize the thermometer, you twist the paper (and the bubble it sits in) to read correctly.