An infrared thermometer is a temperature measurement device that works without coming into contact with the object or surface that is having its temperature recorded. Infrared thermometers detect the infrared, or heat, radiation given off by all materials. By knowing the amount of infrared energy emitted by the object and its emissivity, the object's temperature can be determined and shown as a digital reading.
Infrared thermometers are also called non-contact thermometers because of their ability to measure temperature from a distance. If they use a laser beam for help aiming then they may be referred to as laser thermometers. Many varieties of infrared temperature sensing devices are available, including configurations designed for flexible and portable handheld use, and others designed for mounting in a fixed position to serve a dedicated purpose for long periods.
An infrared thermometer is useful in situations where an ordinary thermometer, or a thermocouple or other probe type sensor, can't be used or doesn't give accurate data. Typical circumstances are where the object to be measured is moving; where the object is surrounded by an electromagnetic field, as in induction heating; where the object is contained in a vacuum or other controlled atmosphere; or in applications where a fast response is needed.
Specific tasks to which infrared thermometers are routinely applied include: