Application principle of thermal resistance of temperature sensor

The thermal resistance of the temperature sensor is the most commonly used temperature detector in the middle and low temperature zone. Its main characteristics are high measurement accuracy and stable performance. Platinum thermal resistance is the most accurate measurement, which is not only widely used in industrial temperature measurement, but also made into a standard reference instrument. 1. The temperature measurement principle of the thermal resistance of the temperature sensor and the temperature measurement of the material temperature sensor are based on the fact that the resistance of the metal conductor increases with the increase of the temperature. The thermal resistors of temperature sensors are mostly made of pure metal materials. Platinum and copper are the most commonly used materials. In addition, the thermal resistors of temperature sensors are now made of materials such as dian, Nickel, manganese and rhodium. 2. Structure of thermal resistance of temperature sensor. (1) The structure and characteristics of the thermal resistance sensing element (resistance body) of the familiar temperature sensor in the thermal resistance industry. From the principle of temperature measurement of the thermal resistance of the temperature sensor, it can be seen that the change of the measured temperature is directly measured by the change of the resistance value of the thermal resistance of the temperature sensor. Therefore, the change of the conductor resistance of the thermal resistance body of the temperature sensor, such as the outgoing wire, will affect the temperature measurement. In order to eliminate the influence of lead resistance, three-wire system or four-wire system is generally adopted. (2) Armored temperature sensor Thermal resistance Armored temperature sensor Thermal resistance is a solid body composed of temperature-sensing element (resistance body), lead, insulation material and stainless steel sleeve, as shown in Figure 2-1-7, its outer diameter is generally 2~ 8mm, and the minimum is up to mm. Compared with the ordinary type temperature sensor thermal resistance, it has the following advantages: (1) small volume, no internal air gap, thermal inertia, small measurement hysteresis; (2) Good mechanical properties, vibration resistance, impact resistance; Can bend, easy to install long service life. (3) End face temperature sensor Thermistor End face temperature sensor thermistor temperature sensor is made of specially treated resistance wire and is attached to the end face of the thermometer. Its structure is shown in Figure 2-1-8. Compared with the general axial temperature sensor thermal resistance, it can reflect the actual temperature of the measured end face more accurately and quickly, and is suitable for measuring the end face temperature of bearing bush and other parts. (4) Through the junction box with special structure, the thermal resistance of the flameproof temperature sensor confines the explosion of the explosive mixture gas inside its shell caused by the influence of spark or arc in the junction box, and the production site will not lead to overshoot and explosion. The thermal resistance of flameproof temperature sensor can be used for temperature measurement in Bla~B3c area with explosion hazard. 3. Composition of temperature sensor thermal resistance temperature measuring system Temperature sensor thermal resistance measuring system is generally composed of temperature sensor thermal resistance, connection wire and display instrument. Attention must be paid to the following two points: (1) The temperature sensor thermal resistance and the indicator must be the same (2) In order to eliminate the influence of the change in the resistance of the connection wire, the three-wire connection method must be adopted. (2) Armored temperature sensor Thermal resistance Armored temperature sensor Thermal resistance is a solid body composed of temperature-sensing element (resistance body), lead, insulation material and stainless steel sleeve, as shown in Figure 2-1-7, its outer diameter is generally 2~ 8mm, and the minimum is up to mm. Compared with the ordinary type temperature sensor thermal resistance, it has the following advantages: (1) small volume, no internal air gap, thermal inertia, small measurement hysteresis; (2) good mechanical properties, vibration resistance, impact resistance, can bend, easy to install long service life. (3) End face temperature sensor Thermistor End face temperature sensor Thermistor temperature sensor is made of specially treated resistance wire and is attached to the end face of the thermometer. Compared with the general axial temperature sensor thermal resistance, it can reflect the actual temperature of the measured end face more accurately and quickly, and is suitable for measuring the end face temperature of bearing bush and other parts. (4) the flameproof thermal resistance temperature sensor flameproof thermal resistance temperature sensor through the special structure of the junction box, its shell internal explosive mixed gas by a spark or arc shadow resistance circuit repair are bound to change the length of the wire resistance and impact resistance, resistance to replace the new body is good, if the repair welding, after welding to be calibrated to use along with the development of The Times, scientific research, agriculture, hvac, textile, machine room, aerospace, power and other industrial sector, increasingly need to adopt the humidity sensor, the requirements of the industry, the higher the quality of product, The control of environmental temperature and humidity as well as the monitoring and analysis of the moisture content of industrial materials have become one of the common technical conditions. Humidity sensor products and humidity measurements belong to the emerging industry in the 1990s. How to use a good humidity sensor, how to judge the performance of the humidity sensor, this is still a relatively complex technical problem for the general user.