A temperature sensor is a device that detects temperature and converts it into a usable output signal. It is a crucial component of temperature measuring instruments and comes in a wide variety. They can be categorized into two main types based on the measurement method: contact and non-contact. According to the sensor material and electronic component characteristics, they are divided into two types: resistance thermometers and thermocouples. Contact temperature sensors require thermal contact with the medium being measured, whereas non-contact temperature sensors do not need to touch the medium and instead use the medium's thermal radiation or convection to reach the temperature sensor for measurement purposes. Common temperature sensors include thermocouples, thermistors, and platinum resistance, each with its own features and application ranges, widely used in industrial production, scientific research, and other fields.
Thermocouples are commonly used temperature sensors made up of two different metals. When the two junctions are at different temperatures, a thermoelectric potential is generated between them, allowing for temperature measurement. Thermistors, on the other hand, measure temperature by utilizing their resistance value, which changes with temperature. Platinum resistance temperature sensors, using the property of platinum's resistance changing with temperature, offer high precision and stability, suitable for measuring temperatures in the medium to low temperature range. Infrared temperature sensors measure temperature by detecting the infrared radiation emitted by an object, boasting fast response times and non-interference with the target.
Additionally, temperature sensors have wide applications, such as in air conditioners, refrigerators, and other household appliances for temperature detection and control, ensuring the normal operation and energy saving of the equipment. In industrial production, temperature sensors are used to monitor and control the temperature during the production process, ensuring product quality and production safety.