How to Calibrate Infrared Thermometers

How Do Infrared Thermometers Work?

Infrared thermometers detect the infrared radiation coming from an object and then convert it into a temperature reading. Objects radiate infrared radiation proportionally to their temperature. This is what the IR thermometer measures to give a temperature value.

The working procedure:

1. Infrared Detection: The surface of the object emits radiation, which is detected by the sensor on the thermometer;
2. Conversion: A detector in the infrared thermometer converts radiation into an electric signal;
3. Temperature Calculation: The processor in the thermometer converts the electric signal into a reading according to the amount of energy detected.

Importance of Infrared Thermometer Calibration

Calibration is vital because the results produced by the infrared thermometer need to be highly accurate and reliable. However, the thermometer can show wrong temperature readings due to dust and debris on the lens, changes in atmospheric conditions, or the wearing out of internal parts.

Reasons for performing calibration

• Accuracy Assurance: Well-calibrated infrared thermometers give accurate readings, thus reducing any chances of error.
• Compliance with Standards: Industries related to food safety, healthcare, and manufacturing have quality and safety standards that need to be met and hence require periodic calibrations.
• Downtime Prevention: Routine calibration helps detect and identify potential risks that could alter the performance of the thermometer.

How to Calibrate Infrared Thermometers

There are several ways to calibrate infrared thermometers. These methods may vary depending on the type of tool used and the amount of accuracy being sought. The following are the most common methods used in the calibration of thermometers:

Ice Water Method

This method uses ice water as a reference for checking whether your infrared thermometer properly returns readings at 32° F (0° C).

1. Fill a container with ice;
2. Add water until all the ice is covered;
3. Leave it to settle for some time;
4. Stir up the mixture to ensure a uniform temperature has been reached;
5. Make sure your infrared thermometer is set to an emissivity setting of 0.98;
6. Aim the infrared thermometer at the surface of the ice water apparatus without letting the thermometer touch the water; 
7. Take a reading.

If properly performed, the reading should be 32°F (0°C). If not, the calibration of the thermometer needs to be corrected.

Boiling Water Method

Similar to the ice water technique, this method uses the boiling point of water as a reference at 212°F (100°C).

1. Heat some water in a container until it hits its full boiling point.
2. Aim the infrared thermometer at the surface of the boiling water while avoiding steam interfacing the head from the thermometer.
3. The thermometer should read 212°F or 100°C; otherwise, calibration should be done.

These procedures are based on a few assumptions. The assumptions are normal atmospheric pressure and sea level due to changes in boiling points that are a result of changes in altitude.

Blackbody Calibration

A more accurate calibration could be performed with the use of a blackbody calibrator. Using a blackbody calibrator is a standard practice in laboratories, manufacturing, and research settings to ensure the accuracy and reliability of infrared thermometers. It emits infrared radiation at known temperatures, thus offering an established reference on which to base the calibration.

1. Set the blackbody calibrator to an established temperature setting, such as 50°C and 100°C.
2. Aim the infrared thermometer at the calibrator and take a reading.
3.  Refer back to the temperature you set on the calibrator. Compare this temperature with the reading of the thermometer. Adjust the settings on the infrared thermometer accordingly to provide the correct reading.

This technique is very accurate; thus, it finds its application in highly sensitive industries that require critical control of temperatures, such as laboratories and manufacturing.

Surface Probe Method

Another technique is utilizing a calibrated surface probe and taking the reading parallel to the infrared thermometer.

1. Heat or cool a surface to a known, constant temperature.
2. Point at the same surface where the exact temperature of that surface is measured by a surface probe, and simultaneously compare its reading with the infrared thermometer.
3. In case there is a different reading, make adjustments to the infrared thermometer.

Troubleshooting Common Calibration Problems

There are other causes of calibration issues. Some general issues and troubleshooting methods include the following:

Variable Readings: The reading is changing while you try to calibrate it. To fix this, clean the lenses of your thermometer of fingerprints and dust. Filthy lenses will give false readings. Additionally, variable readings could be brought on by temperature changes in the surroundings brought about by drafts, heat sources, or cold air. Calibration is best carried out in a controlled environment.

Incorrect Distance: During the time of calibration, you should not be too close or too far away from the object, as this prevents the thermometer from picking the correct infrared radiation. Check guidelines concerning the distance-to-spot ratio as issued by the manufacturer.

How can you ensure that your infrared thermometer is always right? The following are some things to do to keep your infrared thermometer accurate.

• Cleaning: Remove dust and fingerprints that may block the path of the sensor by wiping with a soft dry cloth regularly.
• Controlled Environments: Keep your thermometer away from extreme temperatures, humidity, and shock, as they may impact the thermometer’s accuracy over time.
• Recalibration Schedule: The thermometer should be recalibrated based on the recommendation of the manufacturer. This is often done annually.

ThermoPro TP450 Dual Laser Infrared Thermometer for Cooking

ThermoPro TP450 Dual-Laser Infrared Thermometer for Cooking is a must-have kitchen tool for any culinary enthusiast or professional chef. This advanced infrared thermometer combines precision and convenience, allowing you to measure surface temperatures quickly and accurately without direct contact. Featuring dual-laser technology, the TP450 provides a clearer visual of the measurement area, ensuring you target exactly what you intend to measure.

With a temperature range of -58°F to 1112°F (-50°C to 600°C), the TP450 is versatile enough to handle various cooking tasks, from grilling and frying to baking and candy making. Its ergonomic design and easy-to-read LCD display make it user-friendly, while the adjustable emissivity setting allows for greater accuracy across different surfaces. Plus, with features like a backlit screen and automatic shut-off, the TP450 enhances both safety and usability in the kitchen.