Which statement is true regarding calibration of metal stem thermometers? metal stem thermometers do not require maintenance calibration. calibration is achieved by complete submersion in boiling water for at least 15 minutes. thermometer should register 32°f when using the ice point method of calibration. thermometers must be returned to the manufacturer for routine calibration.

Thermometer should register 32°F when using the ice point method of calibration.

Explanation: Thermometers used in the kitchen should be calibrated on regular basis, therefore option 1 is incorrect. If thermometers are sent to the company, then the people would need more thermometers in spare, which is not economical. Also, the method of calibration is easy and can be conducted anywhere. Thus, option 4 is also incorrect. Boiling water is also used for calibration, but it is more time consuming and handling hot water can be dangerous. So, best method is ice point method.

layer 3 is younger than layer 6.