Pyrometer is used for measuring relatively high temperatures, such as are encountered in hot furnaces. Most pyrometers work by measuring radiation from the body whose temperature is to be measured. Radiation devices have the advantage of not having to touch the material being measured. This type of thermometer can measure the temperature of the object without any contact with the object. Also, it has a fast response time, and good stability while measuring the temperature of the object. Pyrometer is also known as infrared thermometer, or radiation thermometer, or non-contact thermometer.