Radar level measurement technology has gone through many changes over the years. Keith Riley, product marketing manager for level and pressure technologies at Endress+Hauser, recently spoke with Control editor-in-chief Len Vermillion about those changes and specifically 80 GHz radar level measurement technology. You can hear more of this discussion from the Control Amplified podcast series at controlglobal.com/podcasts.
Q: How has 80 GHz radar level measurement technology changed? siemens inverters
A: First, 80 GHz technology continues to evolve. The most recent change is a stronger signal. It was a good signal to begin with, but we’ve been able to strengthen it. Users can also reduce the speed of response of that signal. It's faster and does more evaluation, which accomplishes two things. The stronger signal means users can get an even greater distance than a 26 GHz unit. Also, the speed of response makes it even more reliable and more responsive.
Q: What does that evolution mean in terms of level measurement overall?
A: Historically, there were two different types of free space radar: 6 GHz and 26 GHz. Both were reliable and had spots where they worked well, and still do today. However, with the advent of 80 GHz, a lot of the challenges that were in place have been eliminated. For example, if you go into a normal vessel, maybe it has agitator blades or heating coils. The 26 GHz would work well, but a certain amount of filtering would be needed. We call that mapping, to make sure the instrument would ignore those obstructions.
The 80 GHz, with its higher frequency and naturally narrow beam angle, makes it much more user-friendly to go into those environments and work without nearly as many adjustments. It's changed the landscape about what's needed for free space radars. Users can utilize them where they weren’t available before. Keep in mind that 80 GHz, while an extremely useful tool, is not an end-all solution. Users still need a fit-for-purpose approach, and sometimes there are still places where the 6 GHz or 26 GHz makes more sense. That’s why it’s important to consult with industry experts before making a decision.
Q: Safety is always a big focus, of course. What influence do 80 GHz devices have on safety?
A: Part of risk reduction comes from the basic setup of the device. If users don't have to work so hard to map out things to have a more reliable signal, it inherently increases the safety of their system. This helps prevent human error and minimizes potential mistakes and risks. 80 GHz technology naturally enhances that process.
I think a lot of safety goes together with the HMI that's developed along with 80 GHz technology. Anyone in the chemical industry realizes that probably only 35% of their failures in a safety instrumented system (SIS) are attributable to random failures. Then, 65% of errors are systematic failures, which in most cases can be attributed to human error.
When you look at the newer 80 GHz radar, in addition to enhanced HMI, it has things like a safety integirty level (SIL) wizard, which by itself means you're manually reviewing in a read-only format. It's easy for somebody to either look at a sheet, jump a line when looking at values, or be interrupted when commissioning the instrument for the SIL system. Users can also get interrupted while entering the values for an SIL system and forget to hit “save.” These potential errors can be caught by using the SIL wizard.
This are some ways that 80 GHz radar units with enhanced HMI can improve their processes. The same can be said for proof-testing. If you have something like a proof-test wizard that walks you through the process, and lets users answer questions right on the instrument review, it makes it much less likely there will be human error.
Q: How do instruments such as Micropilot from Endress+Hauser contribute to ease of use?
A: We've addressed the primary ones: narrower beam angle, less mapping and less work to install the unit. That's ease of use from the inherently narrower beam angle. We also can go back to the HMI question, which is what we call a commissioning wizard. This is built into all our new 80 GHz units. It's our way of saying “instrument-led commissioning.” Why is it critical? We see a lot of reduction in experience in the technician and maintenance workforce because of attrition. New technicians—who are intelligent coming in—may still be less experienced with these instruments.
Every smart instrument has its menu structure. Some use slightly different technology for the same setting or function, and it can be difficult for a new technician to become fully acquainted with 15, 20 or 25 different smart instrument manufacturers and their menu structures. The commissioning wizard asks questions, and by filling in those answers, users can successfully commission the device, eliminating human error, and speeding everything up.
Q: What criteria should plant operators consider when assessing if they should utilize 80 GHz free space radar measurement?
A: They should look at the application first. 80 GHz is becoming more universal, so it's a good place to start, but there are a couple of things to consider as well. 80 GHz is good at avoiding obstructions, but if there’s an obstruction in the way of the nozzle, it may not see around it, so there's a simple evaluation. Is there a relatively clear path? What is the process fluid in question? 80 GHz at a higher frequency may have more of an issue with certain vapor spaces, which are at frequencies that tend to attenuate the signal and cause issues. Users must look at what's in the vessel. Ammonia and free space radar don't play well together because it attenuates the signal.
Users should look at the three questions. Thee first focuses on simplicity. Is this device the easiest to set up, maintain and operate safely? Also, what kind of risk reduction is needed, whether for personnel, the process or both? Productivity is also important. Can more products be made, and more revenue created, by using it in the process as it is now? But again, it’s critical to consult with an industry expert or leader. They’ll be able to answer your questions and help you make a more informed decision.
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