Food Standards Code, 3.2.2 Division 6 (22) Temperature Measuring Devices, A food business must, at food premises where potentially hazardous food is handled, have a temperature measuring device that can accurately measure the temperature of potentially hazardous food to +/- 1°C.
State food regulators expect that if the retail store sells hot and cold foods, then their hand held thermometers, surface temperature and probe device, are reference checked to a cold (below 5°C) AND a hot (above 60°C) temperature. Stores that do not sell hot food may reference check to only one cold temperature.
Thermometer kits such as the ECE Fast kit come with at least one 3°C test piece for easy weekly reference checking. If you sell hot food your kit must also contain a 63°C test piece.
Best practice has indicated weekly calibration to be most effective due to the increased level of use of the equipment in a supermarket environment and the importance of ensuring foods are kept within the acceptable temperature range. Storing/displaying food outside of the accepted limits cannot be defended if your temperature devices are inaccurate/damaged.
16.0 - Calibration Program
18.16 - Scales & Thermometer Calibration Checksheet