Question

How is a laboratory thermometer calibrated?

Answer 1

Calibrating your thermometer is quick and easy. Many analog and digital thermometers allow you to offset the temperature to adjust for the calibrated value. However, if your thermometer doesn’t offer an offset function, a piece of blue tape with the delta will work just fine.

Method 1: Ice Water

1. Fill a glass with ice cubes, then top off with cold water.
2. Stir the water and let sit for 3 minutes.
3. Stir again, then insert your thermometer into the glass, making sure not to touch the sides.
4. The temperature should read 32°F (0°C). Record the difference and offset your thermometer as appropriate.

Method 2: Boiling Water

1. Boil a pot of distilled water.
2. Once the water has reached a rolling boil, insert your thermometer, making sure not to touch the sides or bottom of the pot.
3. The temperature should read 212°F (100°C). Record the difference and offset your thermometer as appropriate.
   [Note: The boiling point of water will vary with altitude. Use this handy water boiling point calculator to find the right temperature for your elevation.]