Thermometers shall be calibrated every how many years?

• A. Three years
• B. One year
• C. Five years
• D. Seven years

Answer: (A)

Thermometers drift over time, so they must be checked against a known reference at regular intervals to ensure readings stay within acceptable limits. In this context, the standard calibration interval is every three years. This duration provides a practical balance between maintaining measurement accuracy and the workload of calibration.

Calibrating involves comparing the thermometer to a trusted temperature standard, making any necessary adjustments, and recording the results to demonstrate the instrument meets tolerance. Choosing a shorter interval, like annually, would be more frequent than typically required for shipboard thermometers, while longer intervals such as five or seven years risk drift from the true temperature going undetected, which can lead to unsafe or incorrect readings.