TE Wire & Cable Thermocouple Solutions Blog

Recently, I received a number of questions regarding junctions. Most of the questions are related to the effect of twisted vs. parallel junctions on measurement and performance long term.  To answer this question, I approached my friend and colleague at CCPI, Trevor Ford.

Below are some of the questions he answered in his reply. I hope they help you on your next project or simply answer some of the basic questions you might have while working with thermocouples.

Trevor, using your vast thermocouple sensing expertise, would you be able to provide some pros and cons of twisted (weld/no weld)/parallel welded exposed junctions?

As you approach higher and higher temperatures for your applications, it’s hard not to think of fiberglass insulated products. S-Glass and E-Glass, we refer to as Q-Glass and G-Glass respectively.  These braided products, come in many different variations depending on the use, not to mention there are also different saturants, grades of thermocouple, shields, and armors that can be applied over/to your wire or cable.

Whether you’re using thermocouple wire in the aerospace, industrial or metallurgy markets, I have little doubt that the better you understand the ‘devil is in the details’ when it comes to making the right wire design selection for your applications, the better your chances of success. 

Understanding Noise Levels and Installation Considerations

In part one, we discussed the four types of noise frequently found in instrumentation circuits (i.e., Common Mode, Cross Talk, Static and Magnetic) as well as the methods used to correct the problems they cause.

Next, we discuss the types of noise levels found in various environments and some installation considerations that will help you mitigate or completely eliminate the noise problems.

4 Common Sources of Noise that Affect Instrumentation Circuits

It can be a real challenge to select the right thermocouple wire. You not only have to determine the type of thermocouple elements to use, but also the temperature range, calibration accuracy and insulation type  for your application. With thousands of different configurations, it’s still far less complicated than thermocouple and instrumentation cable circuits. Regardless, it is important to know how to control noise in instrumentation circuits.

Thermocouple (TC) wires are used in a wide range of industries. I have personally worked on some unique projects and it always amazes me how innovative people get especially in the niche applications. For example, one well known aerospace company is designing cryogenic temperature monitoring system utilizing thermocouple wire in space satellites. Cool stuff. Literally.

Tomorrow marks my eighth year of selling thermocouple wire and cable. Like many people, I started in this industry very early and as in any niche industry most of what I learn was by seeing, listening and reading. If you are reading this, you are probably interested in a quick refresher course on thermocouple wire theory and, more importantly, the chemistry of various types of thermo elements.