Thermometers are used to monitor controls and verify that controls have taken place in accordance with expectations. There are a variety of different types of thermometer. However, it is the probe thermometer, fridge thermometers, display thermometers and infra-red thermometers that are most commonly used in catering establishments. In a minority of cases data loggers and automated alarm systems are used as an alternative to manual monitoring by staff. Glass thermometers are not permitted.
The probe thermometer is an important tool as it can be used to monitor and verify hot (for example, when cooking or reheating) and cold temperatures. It must be checked for accuracy once a week. Disinfectant probe wipes are a useful way of disinfecting probe thermometers. Excess food debris should be rinsed off the probe using hot water and detergent. Disinfectant wipes can then be used before and after each application to disinfect probes.
Infra-red thermometers provide a useful quick way of checking the surface temperature of food. They may be used on daily storage checks and deliveries to provide an estimation of temperature.
Where critical limits are exceeded a probe thermometer should be used to check food temperatures or carry out between-pack monitoring. They must not be relied upon for accuracy or be used for checking core temperatures as they will only give an indication of surface temperature. When cooking foods like poultry or meat products like burgers a probe thermometer will be more appropriate.
Refrigerator and freezer thermometers may be used to monitor fridge and freezer temperatures. In-built refrigeration displays on chilled units may be used as an alternative for checking storage temperatures. Weekly checks on fridge thermometers must be made to ensure that they remain accurate.