{"id":2692,"date":"2019-07-01T07:00:58","date_gmt":"2019-07-01T05:00:58","guid":{"rendered":"https:\/\/staging.blogs.yokogawa.de\/chemical-pharma\/uncategorized\/how-noa-can-add-value-for-process-analytics\/"},"modified":"2022-07-04T06:58:24","modified_gmt":"2022-07-04T04:58:24","slug":"how-noa-can-add-value-for-process-analytics","status":"publish","type":"post","link":"https:\/\/www.yokogawa.com\/eu\/blog\/chemical-pharma\/en\/how-noa-can-add-value-for-process-analytics\/","title":{"rendered":"How NOA can add value for process analytics"},"content":{"rendered":"

When it comes to NOA, the discussion often centers on the departure from the classic automation pyramid with all of the ensuing consequences, especially with regard to (data) security. There\u2019s no question of security being compromised. A lot of initiatives have been launched here. I\u2019d like to show you why all of these efforts are worth it. I\u2019ll be using the PAT demonstrator unveiled at the NAMUR<\/a> Annual General Meeting 2018 as an example.<\/p>\n

PAT demonstrator: All it wants to do is communicate<\/strong><\/h3>\n

Various NOA demonstrators were featured in a workshop at the NAMUR Annual General Meeting 2018. Only one of them was concerned with process analytical technology. It was presented by Professor Leon Urbas (Professor of Process Control Systems at TU Dresden) and developed in cooperation with the University\u2019s Process Systems Engineering Group, Yokogawa Germany and the owners of the IGR interest group\u2019s NOA demonstrator at Industriepark Hoechst.<\/p>\n

The analytical heart is an analog pH sensor. A combination electrode just like tens of thousands of others in our brownfield plants. The sensor is installed in a retractable assembly which allows it to be removed from the process at regular intervals and treated with cleaning solution. The measured values and any alarms or warnings are processed in the control system, which also controls the cleaning device.<\/p>\n

The value of the measuring equipment \u2026<\/strong><\/h3>\n

The value of the analytical measuring equipment is clear: the pH generally serves to monitor the process or to navigate through it as it runs \u2013 a kind of GPS guide to the process! If you\u2019ve ever lost your way \u2013 whether driving your car or navigating through an industrial process \u2013 you\u2019ll know exactly what I mean.<\/p>\n

\u2026 and the buried treasure adds even more value<\/strong><\/h3>\n

The sensor carries on measuring during the cleaning phase. The values it measures are not without interest. If a cleaning solution with a defined pH is used, then we have a setpoint. If the sensor reaches this setpoint, this is a sign that it\u2019s working correctly. If the setpoint isn\u2019t reached, the sensor is probably drifting (calibrate it!); it could also be dirty or even about to give up the ghost completely. There\u2019s another interesting phase when the sensor is exposed to the medium again. The sensor indicates a transient curve to the measured value. If it takes longer to settle, that\u2019s also a clue to fouling, for instance on the reference electrode. Even without a cleaning device, signals can still be evaluated, such as the impedance of the reference electrode.<\/p>\n

All of this is highly relevant information about the sensor\u2019s state (of health). And best of all, this information is already there. Without you having to actively collect it \u2013 it simply appears during the cleaning phase. Like a free, more or less continuous medical checkup. And the operator isn\u2019t even aware! The only pointer during the cleaning phase is that the sensor is on hold<\/em>.<\/p>\n

<\/strong><\/h3>\n

Potential treasure-diggers<\/strong><\/h3>\n

Interesting diagnostic data is supplied in this way at short intervals. Yet the sensor doesn\u2019t have much of a brain. It\u2019s purely analog. If it wants to share any knowledge with you, it does it the easy way in HART. There are some signals where every single bit of information literally has to be wormed out of it.<\/p>\n

So who should it share that information with? The control system? The control system would have to record data while the sensor was on hold<\/em>. It would need to compare values with a setpoint at the end of the cleaning phase in order to determine the settling time. And create a history for both values. But the control system\u2019s far too busy for that! And, in any case, it hasn\u2019t even got the capacity.<\/p>\n

Well, what about the maintenance technician? He only notices when he carries out routine maintenance, in other words at very long intervals. That medical checkup will end up being more like a PAThological examination.<\/p>\n

In fact, it\u2019s actually all there already. The only thing that\u2019s actually missing is someone who\u2019ll listen to what the sensor has to say. The PAT demonstrator has a listener \u2013 let\u2019s call him App.<\/p>\n

App \u2013<\/strong>\u00a0the sensor\u2019s audience<\/strong><\/h3>\n

We\u2019ll eavesdrop for a minute on what they\u2019re saying and thinking.<\/p>\n

App: Aha, a cleaning phase. In that case, I\u2019ll take a look at the signals. That dude\u2019s reached the setpoint \u2013 like a shot! I\u2019ll see what the reference impedance is doing next \u2013 that\u2019s OK as well. That dude\u2019s in perfect health. Let\u2019s get all of that entered in the patient\u2019s record.<\/p>\n

x cleaning cycles later<\/em><\/p>\n

App: Watch out, here comes another cleaning phase. Aha, he didn\u2019t quite reach the setpoint this time but he\u2019s still within the tolerance \u2013 not quite as fast but fast enough. The reference impedance is getting close to the limit but it\u2019s still alright. I\u2019d better make a note of that \u2013 the \u201cPAT doctor\u201d could find it useful later on.<\/p>\n

x cleaning cycles later<\/em><\/p>\n

App: Cleaning phase, data analysis \u2026 oh dear, he didn\u2019t reach the setpoint. The whole thing\u2019s too slow and the reference impedance is too high. He\u2019s in a poor state. Do you know what I\u2019m going to do? I\u2019m going to make an appointment for you with your doctor. The PAT doctor can pore over all of my diagnostic data later. Hello, is that the operator? My baby\u2019s in a poor state. I\u2019d urgently recommend<\/em> (NOA recommendation for action!) sending a maintenance technician round to have a look at my sensor.<\/p>\n

\"\"How NOA adds value for the PAT<\/strong><\/h3>\n