A temperature sensor is a device that measures and regulates the temperature of an object or environment. There are many different types of temperature sensors, each with their own unique set of features and benefits. Some of the most common types of temperature sensors include thermocouples, RTDs, Thermistors, and Infrared (IR) sensors.
Thermocouples are one of the most popular types of temperature sensors due to their accuracy and wide range of measurement capabilities. Thermocouples consist of two wires made from different metals that are joined at one end. When the junction between the two metals is heated or cooled, a small voltage is generated that can be used to determine the temperature. Thermocouples are available in a variety of configurations, each designed for specific applications. For example, there are thermocouples that can measure temperatures up to 3000°C (5400°F), while others are designed for use in cryogenic environments (-270°C/-454°F).
RTDs (Resistance Temperature Detectors) are another type of popular temperature sensor. RTDs work by measuring the resistance of a material as it changes with temperature. The most common type of RTD is made from platinum, but other materials such as copper and nickel can also be used. RTDs are generally more accurate than thermocouples and can be used to measure a wider range of temperatures; however, they are also more expensive.
Thermistors are another type of commonly used temperature sensor. Thermistors differ from other types of sensors in that they exhibit a non-linear relationship between resistance and temperature; meaning that their resistance changes drastically with only small changes in temperature. This makes them ideal for sensing very small changes in temperature; however, it also makes them less accurate over larger ranges. Thermistors come in two main varieties: Negative Temperature Coefficient (NTC) which decrease in resistance as temperatures increase; and Positive Temperature Coefficient (PTC) which increase in resistance as temperatures increase.
Infrared (IR) sensors operate by detecting infrared radiation emitted by objects within their field-of-view