Thermocouples

A thermocouple, or thermocouple sensor, is a small device used for measuring temperature. Due to their versatility and ability to accurately identify a range of temperatures, thermocouples are used across multiple industries but often feature frequently in engineering and electrical environments.

There are many different thermocouple types, manufactured for specific applications and environmental conditions. The exact type you need will depend on where and when the thermocouple will be used.

Whatever your application or industry, we have a range of thermocouple thermometers from leading manufacturers. If you know the exact product you're looking for, you can search using our advanced filtering options to narrow down your selection.

Alternatively, if you need some help choosing the right type of thermocouple, get in touch with our expert team who will offer advice on our range.

How do thermocouples work?

Thermocouple temperature sensors feature two or more wires that create a circuit and two electrical junctions. The junctions are then connected to two separate points, one being the site where the temperature is to be measured and the other being the reference point.

The temperature change, or difference, results in a change in voltage within the circuit. The thermocouple can then use the level of current to give an accurate temperature reading via a voltmeter. This is also known in physics as the 'Seebeck effect'.

What are the different thermocouple types?

There are nine different types of thermocouple, with each one featuring slightly different materials and temperature range suitability. The most common ones include:

• J-type thermocouples: Used in many applications due to their versatility and affordability, type-J thermocouple wires are a combination of iron and copper-nickel. They're ideal for multiple instances where a temperature reading is required, but they're not suited to extremely high temperatures or areas that are susceptible to moisture.
• K-type thermocouples: The main advantage of a K-type thermocouple is the extensive temperature range it offers, usually from -328 to 2300°F (-200 to 1260°C). Reliable for a range of applications, K-type thermocouple wires are made from nickel and therefore offer good resistance to corrosion.
• T-type thermocouples: These types of thermocouples are suitable for extremely low temperatures as there's no danger of corrosion in environments where there's likely to be moisture present.
• N-type thermocouples: Providing similar functions to the K-type thermocouple, the N-type features improved stability and is less likely to oxidize. For these reasons, the N-type thermocouple is more costly than its counterpart.

Typical thermocouple applications

Temperature thermocouples are required in a variety of environments, with the type of domestic or industrial thermocouple used dependent on the specific application. Some common applications include:

Automotive industry

Digital thermocouples are used in diagnostics and monitoring to check the temperatures, safety, and performance of components. Temperature monitoring is often required in the manufacture of brake systems and monitoring exhaust gas heat levels.

Food industry

Food monitoring requires the use of thermocouple temperature sensors for accurate temperature measuring. Specific thermocouples are used in this industry for health and safety.

As well as food processing and manufacturing, thermocouples are used in catering equipment such as refrigeration units.

Pharmaceutical and medical industries

Medical-grade thermocouples are frequently utilized as probes in surgical procedures, in the manufacturing of equipment, and as sensors to check and monitor patients' temperatures.

In the pharmaceutical industry, the research and development of drugs, along with many other applications, relies heavily on accurate temperature control and monitoring.

Domestic applications

Thermocouples are not just seen in industrial settings. Equipment found in the home, such as ovens, boilers, and fridges, feature thermocouple temperature sensors to enable functionality, performance, and safety.

Thermocouples for every application at RS

Choose North America's leading distributor of electrical supplies and you'll find thermocouples for every application. Whether you're looking for a specific type of industrial thermocouple or domestic temperature sensors, we have an extensive range of products for all your needs. Our manufacturers include Gefran, Omron Automation, Dwyer Instruments, and RS PRO.

We have solutions for a wide range of operating temperatures in a variety of sizes for your requirements. Simply select your products and order today for quick delivery. For help or advice, our team is on hand to help and it's easy to get in touch.

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