Infrared thermometers are incredibly convenient for quickly measuring temperatures without contact. From checking the temperature of your baby’s bathwater to ensuring your grill is hot enough, these devices have become commonplace. But how do you know if you can really trust the numbers they display? How Do I Know If My Infrared Thermometer Is Accurate is a common question, and understanding the factors that affect accuracy and how to test your device is crucial for reliable readings. This article provides practical methods to determine the accuracy of your infrared thermometer and ensure you’re getting dependable results.
Simple Tests to Verify Infrared Thermometer Accuracy
One of the easiest ways to check your infrared thermometer’s accuracy is by comparing it to a known, reliable temperature source. Ideally, you’ll want a stable object with a known temperature that you can easily measure. A cup of water, properly prepared, makes a great start. Here’s what to do:
- Ice Water Test: Prepare an ice bath with plenty of ice and a small amount of water. Stir the mixture well and let it sit for a few minutes to stabilize. Then, measure the temperature of the ice water with your infrared thermometer. It should read close to 32°F (0°C).
- Boiling Water Test: Bring a pot of water to a rolling boil. Carefully measure the temperature of the boiling water with your infrared thermometer. Remember that the boiling point of water changes with altitude. So you have to consider the factor of altitude.
Altitude (feet) Approximate Boiling Point (°F) 0 212 1000 210 5000 203
If your readings deviate significantly from these known temperatures, it could indicate that your thermometer needs calibration or may not be accurate. Checking against known standards is the best way to start accessing the validity of your temperature reader.
Another test involves using a standard, contact thermometer as a control. Measure the temperature of an object with both your infrared thermometer and a traditional thermometer. For example, measure the surface temperature of a wall and the air temperature in the room with a traditional thermometer. Compare the readings. If the infrared thermometer consistently differs from the standard thermometer, even after adjusting for any known differences (like surface vs. air temperature), it is likely inaccurate. Always check that both thermometers are properly calibrated before beginning such tests.
Repeatability is key when assessing the accuracy of an infrared thermometer. Consistently inaccurate readings are still useful, because you know exactly by how much they are off. Take multiple readings of the same target from the same distance and angle. The closer the readings are to each other, the more repeatable your thermometer is. However, repeatability does not guarantee accuracy; the thermometer could be consistently wrong. Consider these points:
- Ensure the target surface is clean and free of dust or debris.
- Maintain the correct distance-to-spot ratio as specified by the manufacturer.
- Check and adjust for the emissivity of the target material.
Want to learn more about emissivity and how it affects infrared thermometer accuracy? The manufacturer of your infrared thermometer likely has detailed instructions and information about calibration and best practices on their website or in the product manual. Check there first!