When it comes to commercial walk-in coolers, thermometers are your first line of defense in making sure your Walk-In is functioning properly and holding its proper temperature. You can help to avoid food spoilage and excessive food waste by making sure your thermometer is calibrated correctly. Proper temperature also helps decrease the chances of food borne illnesses.
When thermometers are shipped out to their respective buyers they are often already calibrated to be within one degree of accuracy. Unfortunately, the hustle and bustle of being transported to their destination can cause calibration problems. It is best to check all new thermometers for accuracy once you receive them by using the guide below. In addition, if a thermometer is ever dropped it is wise to calibrate it again to ensure it is reading temperatures correctly. There is no strict regulation on how often you should calibrate your thermometer but we recommend setting a regular calibration schedule depending on how often your thermometer experiences large temperature changes. These changes may happen when your cooler gets an extensive cleaning or after a repair to your cooler is complete. If your cooler stores food items it is best to calibrate your thermometer quarterly, especially before any type of health inspections. Using the guide below will help you easily calibrate your thermometer so that it can continue to give you accurate readings.
USDA Guide To Calibrating Dial Thermometers:
1. FILL A LARGE GLASS WITH FINELY CRUSHED ICE.
2. ADD CLEAN TAP WATER TO THE TOP OF THE ICE AND STIR WELL.
3. IMMERSE THE PROBE OF YOUR THERMOMETER A MINIMUM OF 2 INCHES INTO THE MIXTURE, TOUCHING NEITHER THE SIDES NOR THE BOTTOM OF THE GLASS.
4. WAIT A MINIMUM OF 30 SECONDS BEFORE ADJUSTING.
5. WITHOUT REMOVING THE PROBE FROM THE ICE, HOLD THE ADJUSTING NUT UNDER THE HEAD OF THE THERMOMETER WITH A SUITABLE TOOL AND TURN THE HEAD SO THE POINTER READS 32 °F.
You can calibrate digital thermometers in a similar fashion to the steps above.
Some digital thermometers have a reset button or screw and this is what you will adjust in order to get a 32 °F reading when your thermometer is in ice water. Some people use a hot water method in order to calibrate their thermometer. This method can lead to inaccuracies when it comes to thermometers used in walk-in coolers because boiling point changes depending on altitude and because walk-in cooler thermometers are made to measure cold temperatures in the air. Using the boiling water temperature method of calibration inherently causes your thermometer to experience a large temperature change, which can lead to calibration problems. Because of this, it is best to use the ice water calibration method above.