6 Main Causes For Thermocouple Temperature Measurement Errors

Thermocouple Temperature Measurement Errors
Dec 12, 2023
6 Main Causes For Thermocouple Temperature Measurement Errors

Thermocouples are one of the most popular temperature measurement devices used in a wide range of industrial applications. Its versatility and ease of use make it a worthwhile investment. This measuring arrangement is robust and accurate for scientific applications as well.

In this device, two wires that are made of different metals are combined at the tip. Choosing the right Thermocouple manufacturers in India is crucial to ensure the quality of the product. L.D. Bhattar & Co. is the leading manufacturer of High temperature electrical cables. In this blog, we will take a dig into the main reasons for thermocouple temperature measurement errors. Let’s explore more below.

Main Reasons For Thermocouple Temperature Measurement Errors

1. Not Choosing The Right Type

Choosing the incorrect type of thermocouple measurement device can get you into trouble. This is the most common error that is experienced quite often. There are different types of Thermocouples such as B, K, E, R, J, N, T, and S. Each of them has a different range, electrical output, and accuracy. You can avoid this error by confirming the thermocouple jacket’s color as all of them are color-coded.

2. Inherent Variations in Alloys

You cannot expect two batches of wires to be exactly the same. Some errors in the accuracy of this measuring arrangement can happen because of small variations in the alloy percentages at every step of manufacturing. Standard thermocouples can get around 1% of the actual temperature at the measuring junction. This can be accurate for the majority of applications. We suggest ordering thermocouples with special-limit wires to enhance accuracy.

3. Issues with Thermocouple Extension Wire

Reversing the polarity of thermocouple lead wires will lead to inaccurate measurement. This is because of the difference in temperature between the two ends. This can happen accidentally or intentionally, as some thermocouple wires have a red color for the negative wire, which is contrary to the usual convention for electrical wires. We recommend cross-checking the connection and if required, you can also swap the thermocouple lead wires.

4. Environmental Errors

Environmental factors can affect the thermocouple or the device. Environmental factors, such as humidity, pressure, radiation, vibration, or electromagnetic interference, can alter the output or the performance of the thermocouple or the device, leading to errors. For example, if the thermocouple is exposed to moisture or corrosion, it may change its resistance or output, affecting the temperature reading.

5. Age

Thermocouples are undoubtedly reliable temperature measurement devices. However, they can also drift with time. Maximum exposure temperature, frequency of the cycles, and cyclic measurements can impact the metallurgy with a consequent drift, known as ward. This is why you should consider replacing the thermocouple measuring arrangement occasionally.

6. Thermocouple Grounded At More Than One Location

A thermocouple needs to be grounded at one location only. Grounding it at more than one location can result in electromagnetic field generation. This can cause radio-frequency-interference-related problems which affect the accuracy of the device. We suggest either grounding the transmitter or the controller but not both. You can also select transmitters with internal isolation to eliminate a ground loop.

Get The Best Quality High Temperature Cables From Us

L.D. Bhattar & Co. is the leading thermocouple manufacturer in India. Whether you need high-temperature electrical cables or thermocouple measuring arrangements, you can count on us. Check our website or call us today to discuss your requirements. We are here to help you.