What is the material constant of the thermostor

What is the definition and significance of the material constant of the thermistor? For the material constant, what it can achieve is to ensure that the sensitivity of the entire electronic component is guaranteed.

The material constant of the thermistor, that is, the thermistor chip (a type of semiconducting ceramic), is sintered at a high temperature to form a material having a certain resistivity. There is only one B value for each formulation and sintering temperature, so it is a 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 temperature coefficient of resistance, which means that the larger the B value, the greater the temperature coefficient of resistance.

The temperature coefficient refers to the rate of change of the resistance value for every 1 degree increase in temperature. The B value can be converted into the temperature coefficient of resistance by the following formula: temperature coefficient of resistance = B value / T^2 (T is the point temperature value to be converted). The B value of the NTC thermistor is generally between 2000K and 6000K. It cannot be said simply that the larger the B value, the better or the smaller, the better. It depends on where it is used. In general, as a product for temperature measurement, temperature compensation, and suppression of surge resistance, the B value is better under the same conditions. Because the product with a large B value changes its resistance value more with the change of temperature, that is to say, it is more sensitive.

The thermistor is a semiconductor device fabricated using the sensitivity of the semiconductor material to the sensitivity of temperature. The thermistor time constant τ is a parameter describing the thermal inertia of the thermistor. It is defined as the time required for the thermostor to reach the time required to start the thermostor with the ambient temperature of 63%. Very big.

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