There are many applications that require accurate surface temperature measurement but don’t permit the use of a surface probe because it’s not possible to make direct contact with the object whose temperature is being measured. Infrared sensing technology is ideal for use in these cases.
Using infrared radiation for temperature measurement
Infrared radiation is a form of radiant energy invisible to human eyes. We can feel it as heat. On the electromagnetic spectrum, the infrared band sits just outside of the range of visible light.
All objects with a temperature higher than absolute zero emit infrared radiation. The hotter the object is, the higher the frequency of that radiation. Infrared temperature sensing devices detect the infrared radiation’s frequency.
Two types of infrared temperature measurement devices are widely available today. Both work according to the same basic principle, by sensing the frequency of the infrared radiation an object is emitting and translating that into a temperature reading. But they’re otherwise dissimilar.
Infrared thermometers
Infrared thermometers are sometimes referred to as IR guns. These thermometers rely on sensors called thermofiles, which turn incoming infrared radiation into heat using tiny thermocouples. The thermocouples convert that heat into an electrical signal, which is then measured. The result is displayed on a screen in the form of a temperature reading.
While an infrared thermometer can provide a reliable and cost-effective means of obtaining a non-contact temperature reading, it can only measure the temperature of a single point. If you need measurements of multiple points within a larger area, you’ll need to take multiple temperature readings.
Thermal imaging cameras
Thermal imaging cameras are also known as thermal imagers. They work by using a focal plane array sensor. The focal plane array sensor in the TI-128 Digital Thermal Imaging Camera, for example, has pixel dimensions of 640 by 480. Each pixel acts as an independent temperature sensing element, providing over 300,000 individual temperature points in each thermal image or video.
Not only does this technology create a highly detailed thermal image using radiation from the infrared spectrum, but it also allows for temperature data storage. Thermal imaging camera data can also be processed for use in many applications. Analysis tools can be applied to highlight specific elements or display certain values. Each thermal image or video can be saved with a timestamp to report how temperatures change over time.
In addition, because of their advanced optics, thermal imaging cameras can detect temperatures accurately over much greater distances than infrared thermometers can.
How to choose between infrared thermometers and thermal imaging cameras
If your application is simple—you just need to do some non-contact temperature spot checking—and your budget is limited, an infrared thermometer is a good bet.
But if need more information or a deeper temperature profile, then a thermal imager will offer far more robust sensing, imaging, and recording capabilities.
If you have any questions about how to choose the best temperature sensor for your application, contact us today. A member of our team will be happy to help.
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