A thermocouple is a temperature-measuring device consisting of two dissimilar conductors that contact each other at one or more spots, where a temperature differential is experienced by the different conductors (or semiconductors). It produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit.
Thermocouples or thermocouple sensors are a widely used type of temperature sensor for measurement and control, and can also convert a temperature gradient into electricity. Commercial thermocouples are inexpensive, interchangeable, are supplied with standard connectors, and can measure a wide range of temperatures. Thermocouples are classified by calibration type because they have varying electromotive force (EMF) versus temperature curves. Some generate considerably more voltage at lower temperatures, while others do not begin to develop a significant voltage until subjected to high temperatures.
Also, calibration types are designed to deliver as close to a straight line voltage curve inside their temperature application range as possible. This makes it easier for an instrument or temperature controller to correctly correlate the received voltage to a particular temperature. Hi-Watt Inc. carries Watlow Thermocouples, Tempco Thermocouples, Pyromation Explosion-Proof Thermocouples and more.
General Thermocouple Applications
Thermocouples are suitable for measuring over a large temperature range, up to 2300 °C. Applications include temperature measurement for kilns, gas turbine exhaust, diesel engines, other industrial processes and fog machines. They are less suitable for applications where smaller temperature differences need to be measured with high accuracy, for example the range 0–100 °C with 0.1 °C accuracy. For such applications thermistors, silicon band gap temperature sensors and resistance thermometers are more suitable.
Fiberglass and Teflon insulated leads for industrial and commercial equipment. Lead lengths 6 to 360 in. (152 to 9,144 mm) and standard sheath lengths up to 12 inches. Available in J, K, T and E calibrations available.
Watlow is a world class supplier of temperature measurement products, with more than 90 years of manufacturing, research and design expertise. Companies engaged in critical process control of food and metals rely on Watlow thermocouples. Watlow designs and manufactures sensors to meet customers’ industrial and commercial equipment needs.
Tempco Industrial Thermocouple Assemblies
Tempco manufactures many styles of industrial thermocouple assemblies for a wide range of industries, from petro-chemical to textile applications, where one or more protection tubes may be necessary to protect the thermocouple.
Pyromation Thermocouples: Explosion-Proof
Explosion-Proof Thermocouple Assemblies with Thermowells are made for use in U.S. and Canadian hazardous areas. They are designed to extinguish flames inside the device, eliminating the potential for ignition of flammable mixtures in the surrounding atmosphere. FM and CSA approved assemblies, dependent on connection head type, meet XP Class I, Division 1, Group A, B, C, and D; DIP Class II, Division I, Groups E, F, G and Class III, Division 1. The required thermowell is available in standard, heavy-duty, and flanged constructions.