STANDARD OPERATING PROCEDURE
SUBJECT: Calibration of Thermometers /DOCUMENT:
REVISION NUMBER: New /DATE: November 28, 2007
/WRITTEN BY:
/ APPROVED BY:PURPOSE: To calibrate thermometers by ice water and boiling water methods.
RESPONSIBILITY: HACCP Coordinator and/or alternative
EQUIPMENT: Reference Thermometer, containers, wrench or pliers, deep sauce pen or stock pot, potholders
FORM: Thermometer Calibration Log
FREQUENCY: Weekly
PROCEDURE:
Ice Water Method (Refer To Fig.):
1. Fill container with crushed ice.
2. Add cold water to within 1 inch of top of container.
3. Stir mixture well and then let it sit for one minute.
4. Place reference thermometer(HACCP) in container so that the sensing area of stem or probe is completely submerged.
5. Do Not let the thermometer stem/probe touch sides or bottom of container.
6. Let the thermometer stay in the ice water for 30 seconds or until the dial stops moving.
7. Place the thermometer to be calibrated and if it does not read 0˚C. (32˚F.) then adjust nut and rotate until the thermometer dial reads 0˚C. (32˚F.) while in ice water.
8. Repeat process with each thermometer
Corrective action:
Corrective action will be taken if there is a deviation of ± 1˚C
Boiling Water Method (Refer To Fig):
1. Fill the saucepan or stockpot with water and bring water to a rolling boil.
2. Place reference thermometer (HACCP) in container so that the sensing area of stem or probe is completely submerged.
3. Do Not let the thermometer stem/probe touch sides or bottom of container.
4. Let thermometer stay in the boiling water for 30 seconds or until the dial stops moving.
Note: Take safety precautions by properly using pot holders with boiling water and being careful not to let steam come in contact with body.
5. Place the thermometer to be calibrated and if it does not read 100˚C. (212˚F.) then adjust nut and rotate until the thermometer dial reads100˚C. (212˚F.) while in boiling water.
6. Repeat the process with each thermometer.
Corrective action:
Corrective action will be taken if there is a deviation of ± 1˚C
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