AAA Food Manager Certification Practice Test

Which of the following is a method for properly calibrating a thermometer?

1. Boiling water method

2. Room temperature method

3. Saltwater method

4. Ice point method

The correct answer is: Ice point method

The ice point method is a reliable technique for calibrating a thermometer because it utilizes the physical properties of water and ice. To perform this method, you fill a glass with ice and add cold water to create a slushy mixture. The thermometer is then inserted into this mixture, ensuring that the sensing part is fully immersed without touching the sides or bottom of the glass. The thermometer should read 32°F (0°C) at this point, which is the freezing point of water. If it does not, adjustments can be made accordingly. This method is straightforward and provides an accurate reference point for calibration, as it relates to a natural and universally accepted temperature benchmark. Establishing the thermometer's accuracy at this specific point is critical in food safety practices where precise temperature measurements are essential for preventing foodborne illnesses.