Thermistors
A thermistor is an electronic device that changes its resistance in response to changes in temperature. It is a type of temperature sensor that is widely used in many applications, from temperature control in HVAC systems to thermal management in electronic devices. In this article, we will explore what a thermistor is, how it works, and its applications.
What Is A Thermistor?
A thermistor is a type of temperature sensor that uses the resistance of a material to changes in temperature. The name thermistor is derived from “thermal resistor” and is often used interchangeably with the term temperature sensor. Thermistors are commonly made of metal oxides, such as manganese, cobalt, or nickel, and are classified as either positive temperature coefficient (PTC) or negative temperature coefficient (NTC) thermistors.
How Does A Thermistor Work?
A thermistor works by changing its resistance in response to changes in temperature. The resistance of a thermistor decreases as the temperature increases (NTC thermistor), or increases as the temperature increases (PTC thermistor). This change in resistance can be measured and used to determine the temperature of the thermistor.
The resistance-temperature relationship of a thermistor is nonlinear and can be modeled using the Steinhart-Hart equation, which relates the resistance of the thermistor to the temperature in Kelvin. This equation is commonly used to calibrate thermistors and obtain accurate temperature readings.
Applications Of Thermistors
Thermistors are widely used in many applications, including:
Temperature Control: Thermistors are commonly used in HVAC systems to monitor and control the temperature of a room or building.
Thermal Management: Thermistors are used in electronic devices, such as computers, to monitor the temperature of the components and control the cooling system.
Medical Devices: Thermistors are used in medical devices, such as thermometers and incubators, to measure and control temperature.
Automotive Industry: Thermistors are used in the automotive industry to monitor the temperature of the engine, transmission, and other components.
Food Industry: Thermistors are used in the food industry to monitor the temperature of food during processing, storage, and transport.
Conclusion
Thermistors are a type of temperature sensor that is widely used in many applications. They work by changing their resistance in response to changes in temperature and can be modeled using the Steinhart-Hart equation. Thermistors are commonly used in temperature control, thermal management, medical devices, the automotive industry, and the food industry. Understanding how thermistors work and their applications is important for anyone working in temperature sensing and control.