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This article was originally published on April 4, 2022, and updated on June 4, 2025. When installing temperature instruments like bimetal thermometers, RTDs, or thermocouples, a small oversight—such as an improperly fitted thermowell—can lead to costly damage, safety risks or inaccurate readings. Thermowells are essential to protecting your thermometer or temperature sensor and ensuring accurate measurements in high-pressure and high-temperature applications, no matter how extreme the conditions. However, if they are too long or two short for the instrument they need to protect, you will not get an accurate temperature measurement and your instrument can be damaged. At Ashcroft, a leading authority in pressure and temperature instrumentation since 1852, we are often asked how to properly fit thermowells into various temperature instruments. Because there are so many factors to consider, such as making sure you have the correct measurements, knowing if a u-dimension is needed, remembering to subtract the tip thickness from the overall thermowell length and more, it can be easy to get the wrong size if you aren’t paying attention. Read this article to learn about thermowells and the different ways to measure your thermometer or RTD/thermocouple for proper installation. When you are done reading, you will understand what each measurement represents and be more proficient in fitting your temperature instrument with a thermowell. You will also see links to additional articles and resources that are available should you need to broaden your understanding of these instruments further.

If you are just starting a career in oil and gas, chemical processing or any industry that involves flammable materials, dust and other potentially ignitable substances, you need to understand the dangers associated with hazardous locations. This includes knowing what to look for when purchasing instruments for challenging and potentially explosive applications. As a product technical leader at Ashcroft - a recognized authority in pressure and temperature measurement instrumentation - I understand these challenges well. In this article, you will find valuable insights to help you navigate the complexities of monitoring temperature in hazardous location applications. This includes a definition of a hazardous location, the agency standards and approvals required for equipment used in these areas and why temperature instruments, in particular, to be fully certified to ensure the safety and compliance of your operation. When you are done reading, you will have a foundation of information and be more confident about your instrument choices for these challenging applications. You will also have access to additional resources that will deepen your knowledge of RTDs and thermocouples.

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.

In a previous Understanding the Basics blog, I provided an overview of temperature sensors, including RTDs and thermocouples. That article explained how they are used to measure the temperature of original equipment manufacturing (OEM) systems, light industrial processes or other complex applications. Since that piece was published, we have received more questions about RTDs and Thermocouples and the lag options you have when ordering these instruments.

This article was originally published on December 4, 2023, by Rick Zerafin and updated on September 26, 2024. If your work involves critical applications with harsh conditions, extreme weather and high-vibration environments, thermocouples are essential instruments that can keep your system operating efficiently. They are often used in equipment like turbine systems, gas compressors, pumps and other equipment 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. Selecting the correct junction type is critical to ensure optimal temperature sensor performance. With 40 years of measurement instrument experience, I am often asked about the differences and benefits of each junction option. 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.

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.