Temperature Sensors
Temperature sensors identify the temperature of a material or substance and supply this information to the control device of the temperature control system. Temperature sensors are usually electrical or mechanical, typically using either contact or non-contact methods for temperature measurement are contact and non-contact. Temperature sensors are used in measurement systems that can be found in various scientific and engineering applications.
The most common types of temperature sensors include resistance thermometers, thermistors, thermocouples, and silicon bandgap temperature sensors. Resistance thermometers, which display changes in resistance with changes in temperature, are usually made of alloys such as nickel, copper, nickel-iron, or platinum. Thermistors are resistors whose resistance changes with temperature, while thermocouples are temperature measuring devices that consist of two dissimilar metals connected at two points. Silicon bandgap temperature sensors, on the other hand, are used in electronic equipment and can be used in a silicon integrated circuit at very low cost. There are also several different types of displays that can be used with temperature sensors including digital readouts, analog meters, and video display terminals.
While the temperature coefficient, sensor material, nominal resistance, and wiring configuration of RTD sensors are generally decided by the manufacturer, temperature range and accuracy depend on the specific application. When determining the temperature range, the temperature limits of the materials being used and the temperatures they will be exposed to must be considered. The accuracy of the sensor refers to how closely the sensor is able to measure the actual temperature.