A digital thermometer is a convenient tool that reads temperatures in just a few seconds, unlike dial thermometers which can take an entire minute or two to provide a reading. Digital thermometers are very convenient when working with meat, enabling quick readings from different sections and thicknesses of the meat. You can verify if your digital thermometer is reading correctly by testing it in boiling water, and also in ice water.
Fill a cup with ice and then add enough water to just cover the ice. Stir well. Insert the tip of the thermometer about two inches into the ice water, taking care that it does not touch either the side or the bottom of the glass. Wait at least 30 seconds and then check the temperature on the digital face of the thermometer. It should read 32 degrees Fahrenheit.
Bring a pot of distilled water to a rolling boil. Insert two inches of the stem of your digital thermometer into the boiling water and wait 30 seconds. Use tongs or gloves if necessary to keep from burning your fingers. Make sure the tip of the thermometer is not touching either the bottom or the sides of the pot. The number on the face of your digital thermometer should read 212 degrees Fahrenheit. Contact the local health department to find out the temperature at which water boils at your altitude.
Follow the instructions that come with your digital thermometer to reset the temperature if it provides an inaccurate reading. Some models have “reset” buttons, while others can only be reset by licensed professionals, such as technicians authorized by the company that manufactured the thermometer.
References and ResourcesUSDA: Kitchen Thermometers
What's Cooking America: How to Use a Cooking Thermometer
CanadaCutlery.com: Calibrating Thermometers