Principle of temperature measurement of thermal resistance
发表日期：2016-01-09
Thermal resistance temperature measurement principle and thermocouple temperature measurement principle is different, the thermal resistance is based on the resistance of thermal effect of temperature measurement, the resistance value of the resistor body changes with the temperature and the changes in the characteristics. Therefore, as long as the measurement of resistance changes a sense of warm resistance, it can measure the temperature. There are mainly metal thermal resistance and thermal resistance of two kinds of semiconductor.
The resistance of the metal thermal resistance value and temperature generally following the approximate relationship between said, that is type Rt=Rt0[1+ alpha (t-t0)], RT resistance temperature T; Rt0 temperature t0 (usually t0=0 DEG C) when the corresponding resistance value; alpha coefficient of temperature. Semiconductor thermistor resistance and temperature relationship for RT Rt=AeB/t temperature T resistance; a and B determined constants on the structure of the semiconductor material.
Phase comparison, the thermistor temperature coefficient is larger, the room temperature resistance values high (usually over thousands of Europe), but a bad interchangeability, serious nonlinear, temperature range only -50~300 DEG C and a lot for cars, appliances and temperature detection and control. The metal thermal resistance is generally suitable for the temperature measurement in the range of -200~500, which is characterized by accurate measurement, good stability and reliable performance.
Industrial metals commonly used thermal resistance from resistance with temperature changes, most of the metal conductor have this property, but not can be used as a resistance temperature detector, a thermal resistance of metal materials general requirements: as large as possible and stable temperature coefficient, electrical resistivity to (under the same sensitivity reducing the sensor size), in the temperature range with stable physical and chemical properties, the material of good copy, resistance varies with temperature to a value function (preferably in the form of a linear relationship).
The resistance of the metal thermal resistance value and temperature generally following the approximate relationship between said, that is type Rt=Rt0[1+ alpha (t-t0)], RT resistance temperature T; Rt0 temperature t0 (usually t0=0 DEG C) when the corresponding resistance value; alpha coefficient of temperature. Semiconductor thermistor resistance and temperature relationship for RT Rt=AeB/t temperature T resistance; a and B determined constants on the structure of the semiconductor material.
Phase comparison, the thermistor temperature coefficient is larger, the room temperature resistance values high (usually over thousands of Europe), but a bad interchangeability, serious nonlinear, temperature range only -50~300 DEG C and a lot for cars, appliances and temperature detection and control. The metal thermal resistance is generally suitable for the temperature measurement in the range of -200~500, which is characterized by accurate measurement, good stability and reliable performance.
Industrial metals commonly used thermal resistance from resistance with temperature changes, most of the metal conductor have this property, but not can be used as a resistance temperature detector, a thermal resistance of metal materials general requirements: as large as possible and stable temperature coefficient, electrical resistivity to (under the same sensitivity reducing the sensor size), in the temperature range with stable physical and chemical properties, the material of good copy, resistance varies with temperature to a value function (preferably in the form of a linear relationship).
