Which statement describes proper thermometer calibration?

• A. Calibrate before use; check at 32°F with ice water and 212°F with boiling water
• B. Calibrate weekly only
• C. Use at room temp to check accuracy
• D. Calibrate by comparing with another thermometer at 100°F

Answer: (A)

Fixed-point calibration using known reference temperatures ensures a thermometer reads correctly where it matters in food safety. Calibrate before use and verify with ice water at 32°F and boiling water at 212°F. These two points test the instrument across the low and high ends of the range and reveal any offset or sluggish response, giving confidence that readings during cooking, holding, and cooling are accurate. Calibrating only weekly misses the chance that the device drifted since the last check, and relying on a room-temperature check doesn’t test how the thermometer responds to the temps you actually measure. Comparing readings with another thermometer at a single temperature like 100°F doesn’t prove absolute accuracy, since it could share the same error. (Note: at higher elevations, boiling point changes, so adjustments may be needed, but the principle remains: use fixed reference points to confirm accuracy before use.)