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A thermocouple is a type of electrical temperature sensor that is used to measure and monitor temperature changes in process applications. Similar to resistance temperature detectors (RTDs), these sensors are designed to ensure accurate temperature readings in applications where precise temperature control is essential for safety and efficiency. As part of Ashcroft's Understanding the Basics series, this article will provide you with a high-level review of these instruments, including their origin, how they work for different applications and more. You will also gain insights about when to use (or not to use) this type of sensor and be directed to additional resources that can help you deepen your knowledge on the topic of temperature sensors. This information comes from 40 years of industry experience with temperature and pressure measurement, design, engineering, and product management, which includes 17 years working with Ashcroft - a leader in temperature and pressure instrumentation.

Resistance Temperature Detectors (RTDs) are electrical temperature sensors used to measure and monitor temperature changes in process applications. These sensors are important for ensuring accurate temperature readings in industries such as manufacturing, aerospace and healthcare, where precise temperature control is essential for safety and efficiency. As part of Ashcroft's Understanding the Basics series, this article will provide you with a high-level review of these instruments, including how they work, how they are constructed, accuracy classes and more. You will also gain insights about when to use (or not to use) this type of sensor and be directed to additional resources that can help you deepen your knowledge on the topic of temperature sensors. This information comes from 40 years of industry experience with temperature and pressure measurement, design, engineering, and product management, which includes 17 years working with Ashcroft - a leader in temperature and pressure instrumentation.

This article was originally published on October 30, 2023, by Rick Zarafin and was updated by Dave Dlugos. In the article “Why and When is RTD Calibration Necessary?”, we explored how Resistance Temperature Detectors (RTDs), such as our S81 and S50 models, offer superior performance over thermocouples for temperature process measurements due to their high accuracy and repeatability. RTDs are particularly suitable for critical applications, including chemical and refining processes, where precise temperature measurements are essential. To fully grasp the importance of RTD calibration, it is crucial to understand the fundamental working principles of an RTD. As a leader in temperature and pressure instrument solutions, Ashcroft creates articles to address common questions from our customers. Our goal is to provide you with the information and tools you need to make informed decisions about your temperature measurement solutions. In this article, you'll learn how RTDs work, gain knowledge about the different levels of accuracy achievable with RTDs, and see how to maintain and calibrate these devices to meet your specific needs. You will also receive links to additional resources to help deepen your understanding of these temperature measurement instruments.

This article was originally published on October 23, 2023, by Rick Zarafin and updated on August 19, 2024 by Dave Dlugos. As an industrial instrument designer, you are faced with a multitude of temperature measurement options to choose from. In addition to the commonly used infrared, bi-metal, gas-actuated thermometers and thermistors, to name a few. Each of these options stands out as a reliable choice for industrial automation and process applications. However, the instruments predominantly selected for industrial automation and process applications are thermocouples and Resistance Temperature Detectors (RTDs) 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 about the advantages of RTDs and the significance of RTD calibration in ensuring precise and consistent readings for an extended lifespan. You will also be directed to additional resources to help deepen your knowledge about these instruments and their applications.

This article was originally published on August 23, 2023, by Rick Zerafin and was updated on June 26, 2024, by Dave Dlugos. Consistently accurate temperature measurements are vital to several industrial processes in numerous industries from construction to energy to manufacturing. Although many instruments can measure the temperature of gas and liquid in these processes, thermocouples are among the most popular thanks to their simple design and versatility. Over time, however, the thermocouple’s performance may tail off for any number of reasons. Two of the most common are drift and elevated temperature. As a leading authority in temperature measurement instrumentation, we help customers understand the factors to consider when selecting instruments and the steps needed to keep systems running efficiently. If your process includes temperature measurement with a thermocouple, this article will explain why it is important to calibrate your instrument and how to do it. You will also get access to helpful resources that can help you gain deeper knowledge on the subject of temperature sensors.

This article was originally published on July 24, 2023, by Rick Zerafin and was updated on April 29, 2024, by Dave Dlugos. Maintenance, reliability, process and Health Safety Environment (HSE) teams rely on accurate and stable temperature measurements to meet their goals. Thermocouples, new out of the box, are a critical tool for these measurements that help plant personnel maintain safe and efficient operations. Today, instrument designers use a wide array of thermocouple types, such as Type K, Type E and Type T to measure temperatures in applications ranging from cryogenic temperatures of -196 °C to the extremes of 1700 °C. This article will discuss how thermocouple calibration offers added benefits that promote process improvements and support compliance requirements. When you are done reading, you will also find additional related resources that can help you gain more insight into these important instruments.