How can you test if a thermometer is out of calibration?

How can you test if a thermometer is out of calibration?

• A. Check readings in ice water (0°C/32°F) and in boiling water (100°C/212°F); adjust or replace if off by more than tolerance
• B. By tasting the water
• C. By comparing to a standard kitchen clock
• D. By reading the label

Answer: (A)

Testing a thermometer’s accuracy relies on fixed, known temperatures. Use ice water, which should read 0°C (32°F), and boiling water, which should read 100°C (212°F) at sea level. By checking the thermometer against these two stable reference points, you can determine whether its readings fall within the allowed tolerance. If either reading is off by more than what the instrument is rated to tolerate, the thermometer is out of calibration and should be adjusted (if possible) or replaced. This approach works because it anchors the thermometer to exact, reproducible temperatures rather than relying on subjective clues. Boiling point can vary with altitude, so this method assumes standard atmospheric pressure at sea level. If you’re at a different altitude, adjust expectations accordingly or use established calibration guidelines for that environment. Other options don’t test temperature accuracy: tasting water doesn’t provide a true temperature reading, a kitchen clock measures time, and a label only gives product information, not how hot or cold something actually is.

Testing a thermometer’s accuracy relies on fixed, known temperatures. Use ice water, which should read 0°C (32°F), and boiling water, which should read 100°C (212°F) at sea level. By checking the thermometer against these two stable reference points, you can determine whether its readings fall within the allowed tolerance. If either reading is off by more than what the instrument is rated to tolerate, the thermometer is out of calibration and should be adjusted (if possible) or replaced.

This approach works because it anchors the thermometer to exact, reproducible temperatures rather than relying on subjective clues. Boiling point can vary with altitude, so this method assumes standard atmospheric pressure at sea level. If you’re at a different altitude, adjust expectations accordingly or use established calibration guidelines for that environment. Other options don’t test temperature accuracy: tasting water doesn’t provide a true temperature reading, a kitchen clock measures time, and a label only gives product information, not how hot or cold something actually is.