Infrared (Laser) Thermometers

Infrared thermometers use infrared technology to produce accurate temperature readings of food and equipment surfaces. They are quick and easy to use. Infrared thermometers are noncontact thermometers that, when used properly, can reduce the risk of cross-contamination and damage to food products.

To gain the most accurate thermometer reading, remove any barriers between the thermometer and the product being measured and hold and hold the thermometer as close as possible to the product without touching it.

When using infrared thermometers, remember the following:

Infrared thermometers should not be used to measure air temperature or the internal temperature of food. They are designed to measure surface temperature.

Do not take temperature measurements through glass or shiny or polished-metal surfaces, such as stainless steel or aluminum.

Always follow the manufacturer’s guidelines for tips on obtaining the most accurate temperature reading with the infrared thermometer you are using.

Time-Temperature Indicators (TTI) and Other Time-Temperature Recording Devices

Some instruments are designed to monitor both time and product temperature. The time-temperature indicator (TTI) is one example. Some suppliers attach these self-adhesive tags or sticks to a food shipment to determine if the product’s temperature has exceeded safe limits during shipment or later storage. If the product’s temperature has exceeded these limits, the TTI provides an irreversible record of the incident. A change in color inside the TTI indicators or windows notifies the receiver that the product has undergone time-temperature abuse.

More suppliers are using recording devices in their delivery trucks that continuously monitor temperatures. When delivered products appear to have suffered time-temperature abuse, the recording device can be checked to see if the temperature in the delivery truck changed at any time during transit.

General Thermometer Guidelines

Employees should know what different thermometers are used for and how to care for each type. They should follow a few simple rules with all thermometers.

Keep thermometers and their storage cases clean. Thermometers should be washed, rinsed, sanitized, and air dried before and after each use to prevent cross-contamination. Use an approved food-contact surface sanitizing solution to sanitize them. Have an adequate supply of clean and sanitized thermometers on hand.

Calibrate thermometers regularly to ensure accuracy. This should be done before each shift or before each day’s deliveries. Thermometers should also be recalibrated any time they suffer a severe shock (for example, after being dropped or after an extreme change in temperature). Thermometers that hang or sit in refrigerators or freezers can be damaged easily.

To make sure these thermometers are accurate, place a calibrated stemmed thermometer in a cup of water, place the cup next to the hanging thermometer, and check the temperature. Hanging thermometers usually cannot be recalibrated and must be replaced if they are not accurate.

Never use glass thermometers filled with mercury or spirits to monitor the temperature of food. They can break and pose a serious danger to employees and consumers.

Measure internal temperatures of food by inserting the thermometer stem or probe into the thickest part of the product (usually the center). It is good practice to take at least two readings, which should be in different locations because product temperatures may vary across the food portion.

Wait for the thermometer reading to steady before recording the temperature of a food item. Wait at least fifteen seconds from the time the thermometer stem or probe is inserted into the food.

How to Calibrate Thermometers

Calibration is the process of ensuring that a thermometer gives accurate recordings by adjusting it to a known standard. Most thermometers can be easily calibrated. Two accepted methods of calibration are the ice-point method and the boiling-point method. To calibrate your thermometers properly, follow one of these methods.