How Do Thermocouples Work

Thermocouples are integral to our complete solutions in burner management and combustion controls at Profire. Our Type K thermocouples provide accurate readings of extremely high temperatures, signaling the functionality of your production heaters. This includes signaling your system to startup or shutoff as needed based on the internal temperatures of your application. This key element of our power-driven solutions increases on-site safety and efficiency. When working with applications that can range in temperatures from –148℉ to +2462℉ / -100℃ to 1350℃, trust in the durability of our products is crucial.

How do Thermocouples Work

A thermocouple is best described as a device built with two different types of metal wires that work together to measure temperature. The wires are welded together at one end to create a junction point. This is called the ‘hot junction point’ and is essentially how the temperature of the heated substance is determined. When the junction is exposed to heat, it creates a reaction in the electrons within each of the wires. Thermocouples work based on the Seebeck Effect, which is the electromotive force created across two points of dissimilar electrical conducting material. Each of the wires react differently to the heat based on their content, making one the positive, or ‘hot’ wire, while the other is the negative, or ‘cold’ wire. Each wire is composed of various configurations of metal wiring including Iron, Chromium, Nickel, Platinum, Nisil, Constantan, or Copper. The open ends are connected to an instrument that reads temperatures through millivoltage. When there is a temperature difference between the wires it creates a voltage difference. This differential provides accuracy within +/- 35.6℉/2℃ in our Type K thermocouples.

What are Thermocouples Used for

Due to their low-cost and relative accuracy, thermocouples are used in many industrial applications including:

  • Oil and Gas
  • Power Generation
  • Mining
  • BioTech
  • Petrochemical and Refining
  • Renewables
  • Landfill
  • Agriculture
  • Municipal
  • Food and Beverage
  • Construction and Infrastructure
  • Pulp and Paper

They are also used in more common environments such as home appliances including furnaces and stoves. There are many different types of thermocouples that can be used depending on the required accuracy and temperature ranges dictated by the substance being measured. Each type is comprised of different materials and has specific uses.

Type K Thermocouples

Our solutions are utilized with Type K thermocouples. This type is composed of Chromel (+) and Alumel (-). Its tolerance class is +/- 35.6℉/2℃ between –148℉ to +2462℉ / -100℃ to 1350℃. They come in single, dual, triple, and quad formats to accompany all burner management and combustion control systems offered through Profire. We partnered with ThermX and Wika brands to offer 1/4″ and 3/8” OD, 316 SS sheath material, with dual ungrounded isolated junctions. Our thermocouples can be used for many applications in addition to System Accuracy Tests.  A test is completed when two thermocouples are placed in the same environment in proximity. Simultaneous readings are taken from both devices to determine accuracy. Depending on the desired use of the thermocouple, it can be paired with mechanisms to provide additional on-site safety. This could include the ability to activate gas shutoff devices when dangerous situations arise where gas is under pressure at high temperatures, or it will signal to shutdown the heating processes once a desired temperature has been reached. With complete Profire solutions, a thermocouple is essential in providing accurate temperatures for processing and transporting heated materials.

Options for Type K Industrial Thermocouples

At Profire we offer variations of our Type K Thermocouple to better accommodate the many industrial processes of heating appliances we service. We offer a process thermocouple with a direct mount local junction box that comes with a thermowell assembly. The other variation available is a probe format with a preinstalled lead.

Industrial Thermocouples

Profire provides durable and reliable Type K thermocouples for use in the upstream, midstream, and downstream sectors of the oil and gas industry, as well as utility and transmission; biogas; petrochemical and refining; metals and mining; power generation; renewables; landfill; agriculture; municipal; food and beverage; construction and infrastructure; and pulp and paper industries. When our purpose-built control equipment is paired with the proper instrumentation, you will see an increase in on-site safety, reduced emissions, and support for your ESG goals.



For more information on thermocouples and how Profire’s complete solutions can benefit your heated appliances, please contact us.