Infrared thermometer

An infrared thermometer is a <a href="/facts/Thermometer/almVTBxI">thermometer</a> which infers temperature from a portion of the <a href="/facts/Thermal_radiation/1PD9jtCv">thermal radiation</a> sometimes called <a href="/facts/Black-body_radiation/K4YKPKXL">black-body radiation</a> emitted by the object being measured. They are sometimes called laser thermometers as a <a href="/facts/Laser/jk6PTvvT">laser</a> is used to help aim the thermometer, or non-contact thermometers or temperature guns, to describe the device's ability to measure temperature from a distance. By knowing the amount of <a href="/facts/Infrared/44XdJNcc">infrared</a> energy emitted by the object and its <a href="/facts/Emissivity/LUxfMRRI">emissivity</a>, the object's temperature can often be determined within a certain range of its actual temperature. Infrared thermometers are a subset of devices known as "thermal radiation thermometers".
Sometimes, especially near ambient temperatures, readings may be subject to error due to the reflection of radiation from a hotter body—even the person holding the instrument — rather than radiated by the object being measured, and to an incorrectly assumed emissivity.
The design essentially consists of a lens to focus the infrared <a href="/facts/Thermal_radiation/1PD9jtCv">thermal radiation</a> on to a <a href="/facts/Detector/RN8SXbjs">detector</a>, which converts the radiant power to an <a href="/facts/Electrical/hNC8D65W">electrical</a> signal that can be displayed in units of temperature after being compensated for ambient temperature. This permits temperature measurement from a distance without contact with the object to be measured. A non-contact infrared thermometer is useful for measuring temperature under circumstances where <a href="/facts/Thermocouples/FW9cYU5D">thermocouples</a> or other probe-type sensors cannot be used or do not produce accurate data for a variety of reasons.

Infrared thermometer open-in-new

Infrared thermometer