Temperature is one of the basic parameters used and measured in all process industries, to control the machines / equipment and also to monitor the quality of their product.
- Thermocouple consist of two wires or strips that are made of different metals. These wires are joined at one end. As the temperature changes at the juncture, the thermocouple induces a change in Electromotive Force (EMF) between the ends. The EMF of the thermocouple increases with temperature rise.
- Resistance Temperature Devices (RTD): As the name suggests, the resistance temperature devices rely on the change in resistance change of a metal. The resistance rises more or less linearly with temperature. Two key types of the RTDs are the metallic devices, and thermistors. Thermistors rely on the change of resistance in a ceramic semiconductor. As the temperature rises, there is a non-linear drop in the resistance.
- Infrared Temperature Measurement Devices: The infrared temperature measurement devices are non-contacting. They measure temperature from the thermal radiation emitted by a material. The infrared device consists of a lens that focuses the infrared (IR) energy onto a detector. The energy is then converted into an electrical signal by the detector. This signal is then displayed in units of temperature after it is compensated for ambient temperature changes.
- Ultrasound measure temperature: Ultrasonic thermometry is based on the thermal dependence of the speed of sound in materials.? Sound recorded through a process inherently contains information about the temperatures within that process. sensors can acquire temperature and thermal conditions without disrupting flow, altering thermal transport or compromising component integrity.? All of this while allowing the sensor to be isolated from harsh or chemically reactive environments.
