How do I calibrate a digital thermometer?

 

Ice point.

Fill an insulated glass ( Styrofoam cup works well ) with crushed ice and then add a little water.

Let it sit for at least five minutes and then insert the sensing part of the thermometer into the cup.

Make sure the sensor is in the middle of the glass and at least an inch from the sides, bottom, and top of the glass.

Hold it there for 90 seconds or until the dial stops moving or the digital thermometer beeps.

Your thermometer should be reading 32 degrees Fahrenheit after 30 seconds. If it’s not, it needs to be recalibrated.

If  there is no calibration nut then simple math is used to determine if the thermometer is reading high or low.

The ice point method is the most accurate way to calibrate a thermometer.



 

Boiling point.

Boil at least six inches of water.

Once the water has reached a rolling boil, stick the sensor part of the thermometer into the middle of the water, taking care to keep it at least two inches from the sides, top, and bottom. After 30 seconds, the thermometer should read 212 degrees Fahrenheit if you’re at 1,000 feet or less of elevation. See below if you are at a higher altitude. If it doesn’t read 212, your thermometer needs to be recalibrated.

Again  use simple math to determine if your thermometer is reading high or low.



Changes in boiling point temperature by elevation:

Sea Level: 212 degrees Fahrenheit
1,000 feet: 210 degrees Fahrenheit
2,000 feet: 208 degrees Fahrenheit
3,000 feet: 206.4 degrees Fahrenheit
4,000 feet: 204.5 degrees Fahrenheit
5,000 feet: 202.75 degrees Fahrenheit
8,000 feet: 197.5 degrees Fahrenheit