Contactless temperature measurement advantages: measurement limit is not restricted by thermal components heat resistance level, and therefore there is no limit of maximum temperature measurement in principle. For high temperature above 1800 ℃, mainly adopts non-contact temperature measuring method. With the development of infrared technology, infrared radiation temperature measurement by visible light gradually spreading, below 700 ℃ and normal temperature has been adopted, and the resolution is very high.

Advantages and defects: thermocouple sensor sensitivity is lower, it easily affected by environmental interference signal, also easily affected by preamplifier temperature drift, therefore not suitable for measuring the temperature of the small change. As a result of the thermocouple temperature sensor sensitivity has nothing to do with the thickness of material, use very fine material also can make the temperature sensor. Also due to the production of thermocouple metal materials have good ductility, the slight temperature measuring element has high response speed, can measure the process of rapid change.