How to measure the surface temperature of the metal?

Surface temperature measurement is a major aspect of temperature measurement. In machinery, metallurgy, energy and defense departments, measurement of the temperature of metal surface are very common. For example: heat treatment of castings, forgings, gas pipes, steam pipes, wall, etc. Various kinds of metal surface temperature measurement of the furnace, the temperature is from dozens of degrees, a few baidu, for such a temperature, the most commonly used method is to use direct contact measurement method. Surface thermometer is contact method was used to measure various states ( Static, dynamic, or take some objects, etc. ) Solid surface temperature instrument. Surface thermometer has two kinds of magnet and spring thermometer thermometer, it also belongs to the bimetallic thermometer category. It is to use direct contact with the metal surface to be tested, then the pointer to directly show the metal surface temperature. It is to rely on the principle of the double metal induction principle of heat bilges cold shrink to work, by contact spring or magnet at the bottom of the thermometer to measure the metal surface and reading. This type of double metal surface thermometer can range from - 40 c to 500 c, the precision can be & plusmn; 3%. For some of the requirements for accuracy is not high occasions, the use of thermometer of cheap is a money and beauty.