Basic concept of thermistor

Thermistors are a class of sensitive elements whose resistance value varies with temperature. Depending on the temperature coefficient, thermistors can be divided into two types: positive temperature coefficient thermistors (PTC) and negative temperature coefficient thermistors (NTC).

Positive temperature coefficient thermistors (PTC) increase in resistance when the temperature increases. This is because the resistance of the PTC material is positively correlated with temperature, and when the temperature increases, the concentration of carriers in the PTC material decreases, resulting in an increase in the resistance value.

Negative temperature coefficient thermistor (NTC) On the contrary, the resistance value decreases when the temperature increases. This is because the resistance of the NTC material is negatively correlated with temperature, and when the temperature increases, the concentration of carriers in the NTC material increases, resulting in a decrease in resistance value.

These thermistors are usually made of semiconductor materials and are characterized by exhibiting different resistance values at different temperatures, making them useful in a wide range of applications such as temperature measurement and temperature compensation.

The main features of thermistors include:

1. High sensitivity: The resistance temperature coefficient of thermistors is usually 10 to 100 times higher than that of metals, which can produce a sensitive response to small temperature changes and can detect very small differences in temperature with high sensitivity.

2. Wide operating temperature range: Thermistors are suitable for a wide range of operating temperatures. Normal temperature devices are usually applicable to the temperature range from -55°C to 315°C, high temperature devices are applicable to high temperature environments over 315°C, and low temperature devices are applicable to low temperature environments from -273°C to -55°C.

3. Small size: Thermistors have a small size and can be used to measure other temperature sensors The temperature of blood vessels in tight spaces, cavities or organisms that cannot be measured by other temperature sensors. Its small size makes it more flexible and convenient for various applications.

4. Ease of use: The resistance value of the thermistor can be selected at will from 0.1 to 100 kΩ, which can be adjusted and matched to specific needs. This allows the thermistor to be flexible and customizable for a variety of applications.

5. Easy processing and mass production: Thermistor materials are easy to process into complex shapes, which can meet the requirements of different applications. At the same time, the production process of thermistors has been relatively mature, allowing for mass production with high production efficiency and reliability.

6. Stability and overload capacity: thermistors have good stability and strong overload capacity, can work stably under various environmental conditions and can withstand a certain degree of overload current or overload power, with high reliability and durability.