A thermocouple is a type of thermal sensor that’s used to measure temperature changes in solids, liquids, and gasses. At Hi-Watt, we’re proud to sell a wide range of high-quality thermocouple sensors from brands like Watlow®, Tempco, and Pyromation®. Keep reading to learn more about our products.

Types of Thermocouples

Hi-Watt carries several different types of thermocouple sensors: type J, type K, type T, and type E.

Type J

Our Type J thermocouples are useful for applications operating between 95 and 760 degrees Celsius (200 and 1400 degrees Fahrenheit.) 

Type K

Compared to Type J, Type K is better suited for high-temperature atmospheres, as it has exceptional corrosion resistance. It can withstand temperatures between 95 and 1260 degrees Celsius (200 and 2300 degrees Fahrenheit). 

Type T

Our Type T thermocouple sensors are primarily used for cryogenic applications. They can accurately read temperatures between -200 and 350 degrees Celsius (-330 and 660 degrees Fahrenheit). 

Type E

Type E is well-suited for high-temperature applications as it can read temperatures between 95 and 900 degrees Celsius (200 and 1650 degrees Fahrenheit). Type E thermocouples can also be used in vacuum and inert atmospheres.

High-Temperature Applications

Lastly, Hi-Watt carries mineral-insulated thermocouples from Watlow®. Several of the above types are also available as mineral-insulated as well. These are manufactured with XACTPAK®, a metal sheath and mineral-insulated material that helps to protect the thermocouple. This thermocouple also allows for rapid measurements of temperatures up to 1200 degrees Celsius (2200 degrees Fahrenheit). 

To learn more about our Watlow® thermocouples, as well as how to select the best option for your application, please view our blog post.

Thermocouple Accessories

Committed to providing exceptional customer support, Hi-Watt regularly stocks many thermocouple accessories, including thermocouple wire, protection tubes, thermowells, and extension wires. 

All thermocouple wires are identified by the type of thermocouple they are for and are color-coded according to ANSI MC 96.1-1982. 

Hi-Watt’s Trusted Brands

At Hi-Watt, we understand that not all thermocouple sensors are created equal. That’s why we only carry items designed by brands we know and trust. Some of the brands we sell include:

  • Watlow®: Originally founded in 1922, Watlow® has earned a reputation as one of the leading global manufacturers of heating elements and thermal sensors. Watlow® also holds over 450 patents for heaters, controllers, temperature sensors, software, and more.
  • Tempco: Tempco has been a trusted heating solution provider since 1972. Their temperature sensors, cabling, and various accessories are ISO-certified and customized for clients in many industries, including aerospace, automotive, food processing, medical, plastics processing, and transportation.  Special precautions are also taken to help ensure that the temperature sensors won’t become contaminated or otherwise compromised after coming into contact with materials.
  • Pyromation®: Founded over 50 years ago, Pyromation is known for its high-quality, ISO-certified thermocouples, RTDs, and thermowells. Their custom products are perfect for clients in the food and beverage, heat treating, water and wastewater, mining, and plastics processing industries.


Our thermocouples range in design, diameter, and sheath material, and can be customized for a wide range of industry applications, including:

  • Measuring Molten Metal
  • Determining Furnace Temperature
  • Accurate Reading of Low Temperatures
  • Accurate Temperature Reading in High-Pressure Environments

Thermocouple Temperature Sensor for Processing

Our leading lines of thermocouple temperature sensors come with broad temperature range capabilities. Thermocouple devices are widely deployed for process and industry applications due to their measurement ranges and durable construction. Their specifications include various calibrations, with J-type thermocouples and K-type thermocouples commonly used. High-temperature calibrations, such as R and S, are also available.

Factors to review in selecting a thermocouple include temperature range, chemical resistance, system compatibility, and installation requirements. Specific calibrations coordinate with specific temperature ranges. Maximum temperatures are dictated by wire diameter. Call Hi-Watt in Detroit, Michigan to determine the unique advantages our sensors will bring to your company.

NTC Thermistor vs Thermocouple

Similar to an NTC thermistor, a thermocouple is an accurate way to measure resistance and temperature. Thermocouples use two dissimilar metals that are conductive and connected at a single point. This forms two electrical junctions: measuring and reference, also known as hot and cold.

K-type thermocouples use these junction points to maintain two different temperatures and produce low DC voltage that is temperature-dependent. This thermo-electric voltage allows the sensor to measure the resistance, which is used to measure the temperature.

As an all-purpose sensor, thermocouples are capable of extreme temperatures ranging from -200 degrees Celsius to 1,250 degrees Celsius. Despite the larger temperature range, these sensors aren’t always as accurate due to calibration drift.

Compared to an NTC thermistor, thermocouples have a shorter and less predictable lifespan. Expect to replace a thermocouple more often, which results in higher costs.

Learn More About These Dynamic Sensors

At Hi-Watt, we carry the latest Watlow thermistors and reliable thermocouple options. Find out how we can assist you in choosing the best sensor option for your PCB and upgrade your temperature sensors to keep accurate information on hand for your technicians. Contact us today to learn more about the benefits of thermistors and thermocouples and compare leading options to choose the ideal sensor at a great price.