Temperature is representing the degree of cold person objects. In modern life, the temperature is in People's Daily life often requires a quantity of measurement and control. Especially in some high-end scientific research, medical field, very strict to the requirement of temperature measurement and control.
With the development of modern science and technology, sensor technology application is more and more widely. The temperature sensor is the earliest development, the most widely used type of sensor. Galileo thermometer from the 17th century, people started using temperature measurement. True temperature into electrical signal of the sensor is in 1821 by the German physicist bei invention, this is the subsequent thermocouple sensor. Fifty years later, another German Siemens invented the platinum resistance thermometer. With the support of semiconductor technology, this century have developed hot accidentally sensors, semiconductor PN junction temperature sensor and integrated temperature sensor.
Temperature sensors thermal resistance temperature measurement is based on the metal conductor resistance value increases with the increase of the temperature of the properties for temperature measurement. Thermal resistance temperature sensor mostly made of pure metal materials, the application at present most is platinum and copper, in addition, now has started using survey, nickel, manganese and rhodium materials such as thermal resistance temperature sensors.
Thermal resistance is a commonly used temperature sensor industrial heat resistance temperature components from the temperature sensor of thermal resistance temperature measurement principle, the measured the change in temperature is directly measured by the change of the temperature sensor is proposed.theoretical, therefore, the wires of a thermal resistance temperature sensor and so on all kinds of wire resistance change will affect temperature measurement. Three commonly used to eliminate the influence of the lead resistance wire or four wire system. Armored thermal resistor temperature sensor is the thermal resistance element (resistance), wire, insulation materials, stainless steel casing combination solid body, its diameter is generally from 2 to 8 mm, minimum of phi mm. End face temperature sensor resistance end face temperature sensor resistance heat element resistance wire winding by special processing, close to the face in the thermometer. It is compared with general axial thermal resistance temperature sensor, can more accurately and quickly to reflect the actual temperature of end face, is suitable for measuring temperature bearing and other parts of the face. Thermoelectric block type detonation temperature sensor resistance through the special structure of the junction box, put the shell internal explosive mixed gas by affected by sparks or electric arc explosion limit within the junction box, that wouldn't make production field explosion. Flameproof thermal resistance temperature sensor can be used in the Bla ~ B3c zone with explosion danger place temperature measurement.
According to the laws of the interaction between wave and material have been developed acoustic temperature sensors, infrared sensor and microwave sensor. Intelligent temperature sensor is appeared in the mid - 1990 - s. It is the crystallization of microelectronics technology, computer technology and automatic testing. At present, the world has been open out a variety of intelligent temperature sensor series products. Intelligent temperature sensor internal contains temperature sensor, A/D sensor, signal processors, memory, and interface circuit. Some products with multi-channel selector, central controller, random access device and read-only access. Intelligent temperature sensor can output the temperature control of the temperature data and relevant quantity, adapter various microcontroller, can be realized by software and the test function, its intelligent depends on the development level of the software.
As the future development of science and technology, the temperature sensor will be toward a more intelligent and more powerful in the direction of development. The application range of the temperature sensor will be more broad.
