What temperature is used for the boiling method when calibrating thermometers?

What temperature is used for the boiling method when calibrating thermometers?

• A. 212 degrees Fahrenheit
• B. 32 degrees Fahrenheit
• C. 100 degrees Fahrenheit
• D. 180 degrees Fahrenheit

Answer: (A)

Calibrating with the boiling method uses a fixed point—the boiling temperature of water at the calibration environment’s pressure. At standard atmospheric pressure (sea level), water boils at 212°F (100°C). So you heat water to a full boil and check that the thermometer reads 212°F. If it doesn’t, you adjust the thermometer to match that fixed point. The other temperatures aren’t used for this method: the freezing point (32°F) is a different fixed reference, while 100°F or 180°F aren’t fixed points for water at standard pressure.

Calibrating with the boiling method uses a fixed point—the boiling temperature of water at the calibration environment’s pressure. At standard atmospheric pressure (sea level), water boils at 212°F (100°C). So you heat water to a full boil and check that the thermometer reads 212°F. If it doesn’t, you adjust the thermometer to match that fixed point. The other temperatures aren’t used for this method: the freezing point (32°F) is a different fixed reference, while 100°F or 180°F aren’t fixed points for water at standard pressure.