- March 09, 2018
- Emerson Automation Solutions
By Ingemar Serneby, Emerson Automation Solutions
In recent years, industrial automation companies have made enormous advancements by incorporating processors into control devices, instrumentation and networking components. But an instrumentation engineer may feel perplexed when looking at all the options for something as basic as a differential pressure transmitter.
By Ingemar Serneby, Rosemount Level Strategic Product Manager, Emerson Automation Solutions
In recent years, industrial automation companies have made enormous advancements by incorporating processors into control devices, instrumentation and networking components. Improvements in CPUs, wireless platforms and memory have helped industrial devices, just as they have advanced smartphones and other consumer electronics. But just as individuals now have a dizzying range of options for a smartphone or tablet, an instrumentation engineer may feel just as perplexed when looking at all the options for something as basic as a differential pressure transmitter.
At the same time, all these changes are not simply technical. The expectations of how users interact with such devices are also evolving as younger people move into the workforce. A typical millennial has significantly different concepts of technology than baby boomers or Gen-X engineers. As a result, electronic devices, whatever their purpose, must be intuitive and easy to use. If something isn’t plug-and-play and easily configurable via an app, many users won’t consider it.
This discussion of millennials and consumer electronics is nothing new. Many people have been discussing the evolving picture, and several articles have been written on the topic, but how does this trend affect industrial automation product design? To gain some insight, let’s look at an actual instrumentation development situation from both sides: technical features and human interface elements.
The products in question are radar level transmitters (Figure 1). These designs represent the fifth generation of frequency-modulated continuous wave (FMCW) technology (see sidebar), originally developed more than 40 years ago by Saab Marine Electronics which has been part of Emerson’s Rosemount level group since 2001.
Figure 1: Emerson’s Rosemount 5408 non-contact radar level transmitter is available in both conventional and SIL 2 safety configurations.
The implementation of FMCW has improved greatly over the decades. Early-generation transmitters were physically huge, heavy and enormously power hungry (Figure 2). Installing and configuring such a unit required inputting more than 100 settings. Nonetheless, the technology was very effective, and for many critical applications, users were willing to make the effort.
Figure 2: Today’s radar transmitters are much smaller than their predecessors of 40 years ago.
The capabilities of transmitter electronics now make it possible to include an enormous range of features, resulting in products that can “do everything but make coffee for the operators.” But, are new features added because customers really want them, or simply because they can be added at little or no additional cost?
Smartphones are a prime example. Gimmicky things are added to each new model, and these feature-laden products are bought by individuals who insist on having the latest of everything. Technicians and operators in the real world usually know a gimmick when they see one, and having extraneous features often means there are more functions to configure or turn off, making it preferable to avoid them in the first place.
On the other hand, some improvements prove to be highly beneficial, even though customers did not ask for them specifically. Technology providers sometimes find creative ways to help customers deal with the real pain points they face every day. Adding a new feature should reflect those needs, but every user doesn’t necessarily want the same thing.
One radar level transmitter might be purchased for a refinery alkylation unit, while another might be used for a tomato sauce tank in a food processing plant. The circumstances of those users are vastly different, but the same transmitter must work well in both applications.
Modern radar level transmitters reflect use cases and improvement requests gathered over the last 40+ years. With each new design generation, these capabilities improve:
- Power consumption—Earlier units were very power-hungry, but today’s radar level transmitters are two-wire designs operating on as little as 12 V.
- Low dielectric products—The lower the dielectric constant (DK) of the product, the lower the reflected signal; but FMCW technology operates reliably even in applications where conventional pulse-signal units struggle.
- Difficult solids—Modern radar level transmitters can handle solids that form irregular surfaces, are dusty and have a low DK, such as lime. A special calculation algorithm designed for solids helps overcome inaccuracies caused by piling problems.
- Aggressive products—Abrasive and corrosive products are tough on instruments. Even if metallic parts use appropriate alloys, seals and O-rings can wear away, allowing leaks and containment loss. Some radar level transmitters eliminate O-rings entirely, with all wetted parts from stainless steel (or a more specialized alloy if needed) and PTFE.
These are just a few of the technical capabilities built into newer radar level transmitters, with most of these improvements based on user requests and field observations of actual installations. The ultimate objective is to provide features to solve real-world application problems.
Who Reads the Manual?
It’s easy enough to rent a car and drive it for days without a single glance at its user manual. Advanced features may require some effort for implementation, but basic operation does not. Is it possible to design industrial automation instrumentation in the same manner?
The human element remains a major aspect of device design. People must interact with virtually every piece of hardware at some point, and the nature of the interaction matters. In day-to-day production, operators in a plant or control room need to look at various operational situations and take action in a variety of ways. Unfortunately, studies show poor decision-making by operators accounts for about 25 percent of plant incidents, so it is a serious consideration.
It’s difficult to characterize every user in the same way, but regardless of the motivation, everyone seems to want products requiring simple interaction. There is no benefit to confusing set-up processes. On the other hand, some difficult applications require advanced configuration options to handle specific requirements. These should be easily accessible, but tucked away where they don’t need to be used in every situation.
Most users, particularly younger ones, have little patience for devices with long or complex set-up routines. Many technicians open the box and simply start assembling and installing a device based on how they assume it goes together, and can’t be bothered with documentation and manuals. So how should a product be designed to work optimally for every type of user and application?
Observing Users in Their Natural Habitat
One way to improve the user experience is to see how people interact with a product. During the evaluation phase of Emerson’s Rosemount radar level transmitter, we worked with SÖDRA, one of Sweden’s forest product companies, at its pulp mill in Värö (Figure 3) where dozens of level-measuring applications are applied to all sorts of situations. There, we met with Per-Anders Fast and Andreas Berntsson, both experienced instrumentation technicians in the plant. The objective was to allow them to handle the test units, just like they would in an everyday situation, and watch the interaction. We looked over their shoulders, took pictures and notes, and did our best to get natural reactions. What we found provided further insights into how technicians interact with current product manuals.
Figure 3: SÖDRA’s Värö pulp mill is undergoing a major expansion and modernization program, which will make it the world’s largest kraft pulp production facility. Production in 2018 is expected to reach 700,000 tons per year. Photo courtesy Södra Skogsägarna
So how do things work in the real world? After receiving a new transmitter and opening the package, the actual device comes out first. The manual generally stays in the box. Some keep it, while others put it in the recycling bin. The technicians look the instrument assembly over, install it in a way that seems appropriate, and power it up. If there is a problem and it doesn’t behave as expected, the manual may be rescued from the bin. If the manual is not immediately useful, it gets tossed back.
Every product can’t be 100 percent intuitive, allowing users to guess correctly for every operation every time. In most cases, a user can benefit from some documentation. Another great Swedish institution, IKEA, has set an example for minimalist instructions capable of conveying a great deal of information. Along those lines, we created a basic quick-start instruction folder (Figure 4), and attached it to the transmitter using the connection filler plug as the nut. While this seemed like a good idea, we found our technicians gave it a quick look but did not give it the study we’d hoped. Clearly, while attaching it to the transmitter was effective, the presentation was still too long.
Figure 4: An IKEA-inspired quick reference guide provides a lot of useful information, but users don’t always take the time to read it.
Any information presented this way must be very brief, oriented around pictures and diagrams, and must use color to call attention to critical information. This is not easy, but it can be done, and it might cause the technician to dig a little deeper into the documentation. We changed the design to a quick-start card and attached it to the transmitter, also using the filler plug. This approach did draw some engagement and a quick read, although it obviously wasn’t able to transmit all the information of interest.
If the technician does resort to the manual, it should be straightforward, brief and very clear. A given manual must concentrate on the individual product. If a manual tries to cover a variety of related products, leaving the reader to determine which parts apply to what, it will kill engagement. Nobody wants to try and figure out which sections apply to the individual product in question.
Software, quick and simple
Configuring a radar level transmitter, like any complex instrument, is done via a computer working in conjunction with the transmitter itself. Like written instructions, it is important to reduce the amount of required screen reading to an absolute minimum. If the product is designed well, it should require a very short list of configuration points to perform well in most applications.
Emerson created Radar Master Plus (Figure 5) as the main configuration software application, and designed it to emulate the specific application as much as possible. Using images to illustrate the specific application, it is easy to establish setpoints and alarm values while verifying basic readings. Our users at SÖDRA took to it and verified its effectiveness.
Figure 5: Radar Master Plus software is designed to make basic configuration simple, while providing for the advanced selections necessary with complex applications.
Creating an instrumentation product package capable of offering the right mix of performance, features and reliability not happen by chance. It requires a high degree of intentionality, combined with a knowledge of what users need to solve the problems they face every day.
About the Author
Ingemar Serneby works as Senior Application Specialist in the strategic product management team for Rosemount Process radars at Emerson’s Center of Excellence for Level in Sweden. Ingemar has a degree in electrical and electronics engineering from Chalmers University of Technology. He joined Emerson in 1990 and has experience with advanced radar applications throughout the world.Learn More
Did you enjoy this great article?
Check out our free e-newsletters to read more great articles..Subscribe