(1) Long-stem indicating thermometers which are accurate within 0.5° F., plus or minus, for the applicable temperature range, must be provided for checking the temperature of pasteurization and cooling of products in vats and checking the accuracy of recording thermometers. Short-stem indicating thermometers, which are accurate within 0.5° F., plus or minus, for the applicable temperature range, must be installed in the proper stationary position in all HTST and dome-type pasteurizers. Storage tanks where temperature readings are required must have thermometers which are accurate within 2.0° F., plus or minus. Air space indicating thermometers, where applicable, which are accurate within 1.0° F., plus or minus, for the proper temperature range must also be installed above the surface of the products pasteurized in vats, to make certain that the temperature of the foam and/or air above the products pasteurized also received the required minimum temperature treatment.

(2) HTST recording thermometers that are accurate within 1° F., plus or minus, for the applicable temperature range, must be used on each heat treating, pasteurizing or sterilizing unit to record the heating process. Additional use of recording thermometers accurate within 2° F., plus or minus, may be required where a record of temperature or time of cooling and holding is of significant importance.