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.

Industries involving liquids such as chemical/petrochemical, oil and gas, and water/wastewater, are constantly challenged by corrosion. Understanding the different types of corrosion and how they occur is the first step in protecting your process instruments from its damaging effects. As a leading authority in pressure and temperature instrumentation, Ashcroft® offers valuable insights into corrosion and its impact on businesses. This article explores the different types of corrosion, the factors influencing corrosive environments, and the significance of selecting compatible materials for process instrumentation. Additionally, discover key considerations for choosing pressure instrumentation capable of withstanding harsh corrosive conditions.

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.