What is the material constant of a thermistor

I believe everyone has a good understanding of the function of thermistors. Do you know the definition and significance of the material constant of thermistors? For material constants, what they can achieve is to ensure that the sensitivity of the entire electronic component is guaranteed. Let's learn more together with the editor!

The material constant of a thermistor refers to the material formed by the chip (a semiconductor ceramic) of the thermistor after high-temperature sintering, which has a certain resistivity. There is only one B value for each formula and sintering temperature, so it is called the material constant. The B value can be calculated by measuring the resistance values at 25 degrees Celsius and 50 degrees Celsius (or 85 degrees Celsius). The B value is positively correlated with the product's resistance temperature coefficient, which means that the larger the B value, the greater its resistance temperature coefficient.

The temperature coefficient refers to the rate of change in resistance value for every 1 degree increase in temperature. The following formula can be used to convert the B value into the resistance temperature coefficient: resistance temperature coefficient=B value/T ^ 2 (T is the point temperature value to be converted). The B value of NTC thermistors is generally between 2000K and 6000K. It cannot be simply stated that a larger or smaller B value is better, but it depends on where it is used. Generally speaking, products used for temperature measurement, temperature compensation, and surge resistance suppression should have a higher B value under the same conditions. Because with the change of temperature, products with a higher B value have a greater change in resistance, which means they are more sensitive.

Thermistor is a semiconductor device manufactured using the temperature sensitive dependence of the resistivity of semiconductor materials. Time constant of thermistor τ It is a parameter that describes the thermal inertness of a thermistor. Its definition is the time it takes for the temperature change of the thermistor to reach 63% of the temperature difference between the starting thermistor and the surrounding environment. The time constants of various thermistors vary greatly.