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Thermocouples are essential instruments designed to monitor temperature in critical applications involving harsh conditions, extreme weather and high-vibration environments. They are often used in automation, power, pharmaceuticals, life sciences, clean-in-place, refining, and chemical system installations. When configured to meet the demands of equipment like turbine systems, gas compressors, pumps and other equipment, the main function of the thermocouple is to provide clear and reliable signals to communicate whether a system is working properly, or not. In doing so, these instruments help reduce downtime, lower maintenance costs and increase productivity. A key part of the configuration process is selection of the correct junction type for optimal sensor performance. My knowledge in this area is based on 20 years of experience working as an engineer specializing in temperature measurement instruments. In this article, you will learn about the different thermocouple components, including two of the most common types of junctions: grounded and ungrounded. You will also learn the advantages of each junction type, and which is preferable for different applications. When you are done reading, you will have a clear understanding of the best junction to select for your specific needs.

If you read my article, “Why and When is RTD Calibration Necessary?” you learned how Resistance Temperature Detectors (RTDs) such as our S81 and S50 are a better choice than thermocouples for temperature process measurement because of their repeatable, high-accuracy measurement capabilities. More specifically, RTDs are ideal for demanding applications like chemical and refining processes that depend on precise temperature measurements. But to really understand RTD calibration, you also need to know how an RTD works. When I joined Ashcroft — a leader of temperature and pressure instrument solutions across the globe— I brought more than 20 years of temperature application experience with me, and I am happy to share my knowledge with you. In the following article, you learn more about how RTDs work, the different levels of accuracy in RTD calibration and the national and international standards that they are measured against. You will also be directed to additional resources and contact information in case you are ready to take the next step in your decision to select the best temperature measurement solution for your specific application.

If you are an industrial instrument designer, you have several temperature measurement options available to you. These include Infrared, Bi-Metal, Gas-actuated thermometers, Thermistors, Thermocouples and RTDs. Industrial automation and process applications predominantly use thermocouples and Resistance Temperature Detectors (RTDs) instrumentation such as our S81 and S50 because of their proven ability to provide accurate and reliable readings. Each of these sensors has unique advantages and can be configured to match the application needs for optimum service life and performance. Based on my experience working with instrumentation and reliability teams, I’ve seen and compared the benefits of both options. Thermocouples, for example, are often chosen for a robust signal, cost-effective price and ability to withstand most process plant specifications, including harsh vibration and high-temperature range up to 2300° C. RTDs, on the other hand, are the top choice for applications demanding higher accuracy levels and minimal drift. In this article, you will learn more about the benefits of RTDs and why RTD calibration is important to maintain highly accurate and repeatable readings for a longer life span.

Consistently accurate measurements of temperature are vital to several industrial processes in fields from construction to energy to manufacturing. And while there are many ways to measure temperature of gas and liquid, thermocouples are among the most popular thanks to their simple design and versatility. But over time, a thermocouple’s performance may tail off for any number of reasons. Two of the most common are drift and elevated temperature.