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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.

What do race cars, off-highway vehicles (OHV) and any other high-performance machine or system have in common? They are only as good as the instruments you find under the hood. In fact, something as small as the pressure sensing device can have a big impact on the success or failure of meeting your equipment’s operational expectations. As an equipment builder, you expect your OEM pressure measurement instruments to be accurate. That’s a given. But even if it’s not top of mind immediately, what you want even more than accuracy is long-term repeatability. Ashcroft has been manufacturing pressure measurement instrumentation since 1852. So, we understand how challenging it can be to find high-quality, accurate and cost-effective instruments that go the distance to deliver consistent performance over the long term. This is especially relevant for sensors used in tough conditions involving exposure to wide temperature ranges, high cycle life expectations and vibration. Each of these could affect the accuracy and repeatability of critical pressure measurements. This article will explain the elements of an OEM pressure sensor, clarify the difference between repeatability and accuracy, and show you what makes a sensor accurate and repeatable over time. When you are done reading, you will know the key factors to look for when purchasing a high-performance pressure sensor for demanding cycle life conditions which can be common to many applications.

Heating, ventilation and air conditioning (HVAC) systems are a critical part of a building’s operation. They ensure that an indoor environment is comfortable for occupants by controlling humidity, temperature and air quality. However, the cost of running these systems can be a concern for building owners as inefficiencies in an HVAC system could increase building management costs, especially if the pressure sensors used to monitor and control the system are not accurate.

There’s a wide range of accessories for your pressure instruments that can help make your process safer, more efficient and precise. Snubbers, dampeners, capillaries, pressure limiting valves, siphons and other accessories are common additions to the most challenging applications. One question I’ve heard often during my time in this industry is: do these accessories impact the accuracy of pressure measuring instruments?