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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.

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.

Industrial pressure switches have many functions. They are used to regulate water pressure in homes and buildings, maintain water levels in reservoirs and tanks, monitor and control pressure in HVAC systems and pumps, to name a few. However, at Ashcroft, a majority of our customers use pressure switches as a safety mechanism to set off an alarm or trigger a system shutdown when high- or low-pressure limits are reached. Ashcroft is an industry leader in pressure measurement instrumentation. We created this article for new customers like you who want to know how pressure switches can function as an alarm or to shut down their systems. Read on to learn about the different types of pressure switches commonly used in these applications and the additional approvals these switches may need to be used in this capacity. When you’re done reading, you will also find additional resources about switches that may interest you. .

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 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.