►Fill an insulated cup with crushed ice and water.
►The cup must have enough crushed ice to provide an environment of 32°F, so you may need to pack more ice into the cup during the process.
► When the mixture of the water has stabilized in about four or five minutes, insert the thermometer to be calibrated to the appropriate immersion depth.
►Be sure to hold the stem of the instrument away from the bottom and sides of the container (preferably one inch) to avoid error.
► If your thermometer is not accurate within +/- 2°F of 32°F., adjust the thermometer accordingly. The ice point method permits calibration to within 0.1°F.
► Place distilled water in a container and heat.
► After the water in the container has reached a complete “rolling” boil, insert the instrument to the appropriate immersion depth.
► Be sure there is at least a two-inch clearance between the stem or sensing element and the bottom and sides of the container.
► If your thermometer is not accurate within +/- 2°F of 212°F., adjust thermometer accordingly. The boiling point method permits calibration to within 1.0°F.