Temperature controls are devices that monitor and measure the temperature of a gas or liquid for safety applications. In systems that use a heat source, they adjust the passageway of heat energy into or out of the space in order to achieve a desired or safe temperature. They accept inputs from temperature sensors or thermometers, determine the temperature and send a control signal to alter the temperature until it is at the correct level.
Related Categories

Temperature controls 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 temperature controls, 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 thermocouples 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 typically 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 also designed to act as the heat sensors in temperature control systems, and 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 temperature controls 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 temperature controls are equipped with either a digital front panel, which is fast and simple, or a analog components like knobs, switches or meters.