When calibrating a thermometer using the ice-water method, what target temperature should the bath reach?

When calibrating a thermometer using the ice-water method, what target temperature should the bath reach?

• A. 0°C (32°F)
• B. -10°C
• C. 100°C
• D. 25°C

Answer: (A)

The target temperature for an ice-water calibration is 0°C (32°F). This is the freezing point of water at standard atmospheric pressure, and when you have a mixture of ice and water, the temperature stabilizes right at this point. That stable 0°C serves as a reliable fixed reference to check whether the thermometer reads accurately. To do it correctly, use crushed ice and clean water to make a slushy ice-water bath, stir to ensure uniform temperature, and insert the thermometer so the sensing end is fully immersed without touching the sides or bottom of the container. Wait for the reading to stabilize; if the thermometer shows 0°C, it’s properly calibrated. If it doesn’t, adjust or recheck the setup. Why the other temperatures don’t fit: -10°C would require a colder medium than an ice-water mix can provide; it’s not a fixed reference point available with ordinary ice and water. 100°C is the boiling point of water at standard pressure, not the temperature of an ice-water bath. 25°C is room temperature and does not represent a fixed point for calibration.

The target temperature for an ice-water calibration is 0°C (32°F). This is the freezing point of water at standard atmospheric pressure, and when you have a mixture of ice and water, the temperature stabilizes right at this point. That stable 0°C serves as a reliable fixed reference to check whether the thermometer reads accurately.

To do it correctly, use crushed ice and clean water to make a slushy ice-water bath, stir to ensure uniform temperature, and insert the thermometer so the sensing end is fully immersed without touching the sides or bottom of the container. Wait for the reading to stabilize; if the thermometer shows 0°C, it’s properly calibrated. If it doesn’t, adjust or recheck the setup.

Why the other temperatures don’t fit: -10°C would require a colder medium than an ice-water mix can provide; it’s not a fixed reference point available with ordinary ice and water. 100°C is the boiling point of water at standard pressure, not the temperature of an ice-water bath. 25°C is room temperature and does not represent a fixed point for calibration.