Heat Sensors

Heat Sensors

Heat sensors are safety devices that prevent gas leaks, explosions, fires and overheating, all of which can cause serious damage and health hazards. Gas water heaters, diesel fuel engines, heating systems and furnaces for residential, industrial and commercial buildings all employ heat sensors, specifically thermocouples, to monitor, measure and control temperature levels in these systems. The oil and gas, petrochemical, water heating, pharmaceutical, food, brewing, power generation and metal fabrication (mainly iron and steel) industries all use thermocouple instruments that are attached to a temperature reading device as temperature control systems. They are simple in composition, long lasting, reliable and require little maintenance. Thermocouples are made of two wires of dissimilar metal alloys that are joined together by welding at one end, which acts as the sensor, and attached to a measuring device at the other end. For insulation and protection, these wires are enclosed in a metal casing, often made of copper.

Thermocouples are a popular form of heat sensors in temperature control systems because they are accurate, fast and use electrical voltage to determine the temperature of a liquid or gas. Their welded wire tip that acts as the sensor is placed directly in the area to be measured. The heat generates an electric current, which is carried by the wires to the measuring device on the other end. The voltage power change is directly proportional to the temperature of the liquid or gas. The temperature difference from the opposite ends of the wires is then deduced from a measurement of the difference in thermoelectric potentials developed along the wires. Other heat sensors include simple thermometers, resistance temperature detectors and thermistors. The latter two use the principles of different metals’ electric resistance, which also varies with temperature. These are equally as accurate, but have a limited temperature measurement capability. All heat sensors are equipped with either a digital front panel, which is fast and simple, or a analog components like knobs, switches or meters.