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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.

A 4-20 mA analog output is a universally recognized industry standard for relaying electrical signals (as currents) over long distances. For example, many sensing instruments such as pressure transmitters and transducers use a 4-20 mA output as a simple and reliable method to convey information from the field to a system control room. If you want to learn more about this type of output, and the benefits of the 2-wire connection option vs. a 3-wire option, you've come to the right place. I have been a product leader at Ashcroft for almost two decades and have extensive experience in pressure and temperature measurement. During that time, I've been asked a lot of questions about how things work and the benefits of selecting one measurement device over another. We created our Understanding the Basics series to give those who are new to the industry a framework of information to use as a valuable point of reference when needed. In this article, you will learn about 4-20 mA analog outputs, including where they are used, how they work, and the advantages and challenges of using the 2-wire vs. a 3-wire in your application. When you're finished, you'll know if this type of output is right for you.

If you work in any industry that involves potable water systems, you understand the importance of ensuring the water is safe for consumption. That’s why the Environmental Protection Agency (EPA) requires a third-party guarantee that any components in contact with the water in these systems will not contaminate public water supplies. The National Sanitation Foundation's NSF/ANSI/CAN 61 certification (moving forward referred to as NSF 61) of these types of components satisfies this EPA requirement, so you can be confident when selecting them for your water systems. As part of our Understanding the Basics series, Ashcroft – a leading manufacturer of pressure and temperature instrumentation used in water/wastewater applications – created this article to address the questions we receive from our customers about NSF-61 and the products we offer that meet this certification. Read on to learn more about NSF 61, the benefits of using NSF 61 certified components and the Ashcroft instruments that bear the NSF 61 stamp of approval. Once you have finished reading, you will be well-versed on the topic and confident about choosing NSF 61-approved products for your water applications.

Ashcroft has written other articles on selecting the best pressure gauges or pressure transducers for ammonia applications (see links at the bottom of this piece). However, we noticed we were still getting questions from people about the ammonia element itself. So, for the industry novice, this article will take a step back to address those specific questions. Ashcroft pressure and temperature instruments are used in virtually every type of industrial application, including ammonia, so it is our job to know how they will perform in every situation. Here we will review a couple of ammonia applications, and what to look for when selecting the best pressure gauge for your specific needs. At the end of the article, you will find additional resources that may interest you.

If you work in any industry where you need pressure instrument assemblies mounted on diaphragm seals, fluctuations in ambient temperature can affect the accuracy of your pressure instrumentation, especially in low-pressure systems. To help minimize temperature fluctuations and improve the accuracy of your instrument readings, we recommend keeping the fill fluid volume as low as possible using a low-volume tee fitting in your diaphragm seal assembly. As an industry leader in pressure and temperature instrumentation since 1852, Ashcroft developed a series of Understanding the Basics articles that cover common process industry topics and terms. If you are new to manufacturing or process applications or just want a refresher, this is a great place to start. Read this article to learn the basics of low-volume t-fittings, including what they are, how they work and the benefits of using them as part of your assembly for these types of applications.