Technical parameters and characteristics of thermistor

Thermistorvalue RC: generally refers to the actual resistance value of the thermistor when the ambient temperature is 25 ° C. Actual thermistor value RT: resistance value measured at a certain ambient temperature. Material constant: It is a parameter describing the physical properties of the thermistor material, and it is also a thermal index. The higher the value of B, the higher the sensitivity of the thermistor. It should be noted that in actual operation, the value of B is not such a constant, but slightly increases with the increase of ambient temperature< Br/>

The four temperature coefficients of resistance: it represents the change rate of resistance value when the temperature changes by 1 ° C,. Time is a constant: the thermistor has thermal inertia, and time is constant, which is a parameter describing the thermal inertia of the thermistor. It is defined as the time required for the temperature of the thermistor to change 63.2% of the two specific temperature differences when the ambient temperature suddenly changes from one specific temperature to another specific temperature without power consumption. The smaller the impact of thermal inertia through the thermistor is

Rated power PM: under the specified technical conditions, the allowable power consumption of thermistor under long-term continuous load. The rated output power shall not be exceeded in actual use. When the ambient temperature of the thermistor exceeds 25 ℃, the load of the thermistor shall be reduced accordingly. Nominal working current IM: the specified nominal current value of thethermistorunder working condition. Power measurement: under the specified ambient temperature, the change of heating resistance value of the thermistor body under the test current shall not exceed 0.1% of the power consumption

Working voltage: For NTC resistor, it refers to the large DC system voltage that can be continuously applied to prevent thermal runaway caused by thermistor under the specified ambient temperature. For PTC thermistors, under the specified ambient temperature and static air, in order to ensure the normal operation of the thermistor in the PTC characteristic section, it is allowed to continuously apply large DC voltage to thethermistor. Working temperature TMAX: The high temperature at which the thermistor can work continuously for a long time under the specified technical conditions

Switch temperature TB: the temperature at which the PTC resistance value starts to jump. Dissipative structure coefficient H: the power dissipated by the thermistor when the temperature rises by 1 ℃. The main characteristics of thermistor are: high sensitivity, resistance temperature coefficient is 10~100 times higher than that of metal, and temperature change of 10~6 ℃ can be detected< Br/>

The working environment temperature changes in a wide range. The normal temperature device can be applied to - 55 ℃~315 ℃, the high temperature protection device is mainly applied to above 315 ℃, and the low temperature control device is designed to be applied to - 273 ℃~- 55 ℃; It is small and can measure the temperature of air space, cavity and biological blood vessels that cannot be measured by other thermometers; Easy to use