Type K Thermocouples

What Is A Type K Thermocouple?

Type K Thermocouple is a Base metal thermocouple made from conductors containing Nickel – Chromium, and Nickel – Aluminium alloys and is suited for measuring temperatures up to +1200°C. We are K-type thermocouple manufacturers and can produce K-type thermocouple sensors based on your specifications or as replacements for existing sensors. We have manufactured thermocouples for over 25 years and are solely focused on designing and manufacturing temperature sensors. Please call or email us to discuss your requirements.

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If you are unsure exactly what you need, get in touch and we can help identify your requirements.

How Do Type K Thermocouples Work?

Type K thermocouples operate based on the Seebeck effect, which generates a voltage when there is a temperature difference between the two junctions of dissimilar metals. This voltage is proportional to the temperature difference and can be measured to determine the temperature at the sensing junction accurately. The relationship between temperature and voltage is well-characterised and can be represented by specific calibration tables or equations.

Type K Thermocouple Designs

K type thermocouples can come in a variety of designs suited to different applications. View the details of each type of design we offer for the type K thermocouples range.

K Type Thermocouple Specifications

K type thermocouple sensors are by far the most common thermocouple type in use. It is quite an inexpensive sensor and we can manufacture many different designs of this thermocouple type. Its range is common for many industrial processes and is the main base metal thermocouple before switching to a rare metal thermocouple. The high nickel content of Type K means it is a very stable sensor. Thermocouple type K is unsuitable for reducing atmospheres unless it is protected by a sheath. It’s sensitivity is around 41 µV/°C.

Type K Thermocouple Temperature Range


0 to +1100 °C

Short Term:

-180 to +1300 °C

Type K Thermocouples Material

Chromel (90%Ni, 10%Cr)

Alumel (95%NI, 2%Mg, 2%Al, 1%Si)

Type K Thermocouple Tolerance Details

Tolerance Class 1

-40 to +375 ± 1.5 °C

375 to 1000 ± 0.004*[t]°C

Tolerance Class 2

-40 to +333 ± 2.5 °C

333 to 1200 ± 0.0075*[t]°C

Type K Thermocouple Colour Codes

IEC Colour Code

Type K IEC Cable Colour Coding

BS Colour Code

Type K BS Cable Colour Coding

ANSI Colour Code

Type K ANSI Cable Colour Coding

How To Test A Type K Thermocouple?

Testing a Type K thermocouple involves verifying its output voltage or temperature readings against a known reference source or calibrated instrument. This can be done using specialised thermocouple simulators, temperature baths, or other temperature measurement devices. Additionally, visual inspection for physical damage or signs of wear can also indicate the need for replacement or recalibration.

How To Calibrate A Type K Thermocouple?

Calibrating a Type K thermocouple involves comparing its output against known temperature standards over a range of temperatures. This process ensures that the thermocouple provides accurate temperature measurements within the specified tolerance limits. Calibration can be performed using certified temperature references and calibrated instruments following established procedures and standards.

How To Check A Type K Thermocouple With A Multimeter?

To check a Type K thermocouple with a multimeter, you can follow these steps:

  1. Set the multimeter to measure voltage (mV).
  2. Disconnect the Type K thermocouple from any circuitry.
  3. Connect the multimeter leads to the two ends of the Type K thermocouple.
  4. Read the voltage displayed on the multimeter.
  5. Compare the measured voltage with the expected voltage at a known temperature using Type K thermocouple reference tables or conversion formulas.

Which Wire Is Positive On A Type K Thermocouple?

In a Type K thermocouple, the positive wire is typically made of chromel (Nickel-Chromium), while the negative wire is made of alumel (Nickel-Aluminum).

Contact us

We’ve made Type K Thermocouples for over 25 years and today we are considered the best choice for custom built temperature sensors in the UK. We continue to apply our expertise and invest in the latest technology to provide our customers with the highest quality temperature sensors available.

Contact us with your requirements if you have an existing sensor design or are unsure what you need we’ll be able to find you get the right sensor for your process.

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