Transmitters pt 2

Sean continues the conversation with Tony about pressure transmitters. Does accuracy really matter to end users these days? with IOT developments, is it true that miniaturization is on the cards? Listen to this episode to find out 

Transcript

 [00:15] - Sean 
This is a Yokogawa Australia and New Zealand podcast. Welcome back to Yokogawa Debunks, conversations with industry experts to demystify misconceptions we hear in process instrumentation and industrial automation. I'm your host, Sean Cahill, and thank you for joining us. Now with us again today is Tony Farah, product manager for transmitters at Yokogawa Australia and New Zealand. In our last episode, we delved into what is currently happening with communications protocols in transmitters, and we were wondering whether there's any truth to the 4 to 20 mA HART might be superseded by Ethernet. 

 [00:51] - Sean 
We also posed a question to Tony about transducers versus transmitters, and today we continue our chat with him. So, Tony, welcome back. 

 [01:01] - Tony 
Thanks Sean. Good to be back with you on the podcast this morning. 

 [01:05] - Sean 
Now, Tony, just starting off today: of all the choices out there from different manufacturers that make pressure transmitters, it seems to be that sensitivity becomes a competitive feature and that everyone's sensors are getting more and more accurate. In your experience. Do you think it's true that sensitivity and accuracy really matter to end users? 

 [01:26] - Tony 
Absolutely, Sean. And most technologies have evolved with higher accuracy. And that's one of those specifications that quite often is used to try and lockout different technologies. When you look at the trend in the world in general, there's probably only around two to three percent of the measurements that really require a very, very accurate measurement that would be across a broad spectrum of industries ranging from chemical, petrochemical, mining and all the other industries. When we look at oil and gas in particular, as an example, one of those applications with this extremely high accuracy is required would be balances over plant of the raw product in and the final product out. 

[02:14] - Tony 
However, that is really a very small segment of the process in the general processing. In other areas, repeatability is rather more critical and a constant requirement within the processing. So if you looked at a level in particular, whether the level is being controlled at 52 or 55 per cent, it doesn't really matter as long as it remains within a small bandwidth of three or four per cent in many instances. So the extreme high accuracy would not be of such a critical aspect for that type of application. 

[02:50] - Tony 
Does that answer the question for you, Sean? 

 
[02:53] - Sean 
OK, thanks, Tony. It certainly does, and thank you for that concise response there. I look, I've got another question for you here, Tony, which which is with regards to Iot developments and it seems that pressure transmitters will eventually be downsized and miniaturised. If you believe what you hear. In your experience, you think this will happen. And is it something that you envisage will change transmitters as we know them? 

[03:17] - Tony 
Sean, yeah, I absolutely think that there is if evolution in the transmitter technologies, but it's going to take some time before we going to get to having a miniaturisation version of a very robust industrial type pressure sensor that is acceptable to all industries. One of the limitations within the miniaturisation that presents challenges to the users is the inflexibility within these devices. Quite often with what you order is what you get. The transmitter comes with a fixed range and very little diagnostics. 

[03:50] - Tony 
One of the other challenges is communications with these devices that may require certain types of peripheral devices for interfacing to extract some of the data from these devices, which in turn presents another requirement for different skill sets within an operation. This is another challenge for the user of these type of devices. So I feel that diagnostics within the current robust industrial type sensor as a pressure transmitter is one of the more acceptable pressure sensors in some of the more critical applications. The OEMs like Yokogawa really formulate the manufacturing and designs of the devices to meet global requirements. 

[04:36] - Sean 
Thanks a lot, Tony. that's a good response about how technology sometimes need to evolve before it's implemented. So it's also brought up a thought to me about a previous question, which was around accuracy. Now, something also seems to be a bit of a specification battle between vendors. Is the long-term stability of a pressure sensor, in your opinion? What would cause a pressure transmitter to lose its repeatability? And and what kind of things can you do to prevent that from happening? 

[05:08] - Tony 
So I guess we need to firstly look at what the causes are for this type of an occurrence. And often this is as a result of some hiccups in the processes that would result in other specifications, events that occur. In particular, one of the worst events that occur is over pressuring of pressure transmitters. Now, in another pressure scenario, the transmitter that's measuring the pressure, the design of the transmitter very much determines what the accuracy would be of the transmitter. 

 
[05:37] - Tony 
So if we take a technology like capacitance technology effectively, which I would relate to in a very simple analogy, analogy of a flexible sheet of metal, let's say we take this sheet of metal and we hand it to Peter. And with along with that piece of metal, I give Peter a hammer. I ask Peter to give that sheet of metal to smack it will deform the sheet of metal. We that very same sheet of metal that's now deformed and give it to Jack with the same hammer. 

 
[06:07] - Tony 
I request Jack to give that sheet of metal a blow on the opposite side to try and reshape that sheet of metal back to what it was before Jack had given it the first blow. I can guarantee you that that sheet of metal will never return to its original state. So in essence, the capacitance technology being a floating cell has the effect that when another pressure event occurs, the shape on the capacitance sensor will then deform, which will then give it an offset which we call shift or drift. 

[06:40] - Tony 
So effectively the stability on the device would be guaranteed under very limited conditions. However, when you look at some of the more advanced technologies like Yokogawa’s DpHARP technology, with the overpressure, design and stability within that device, the stability of the transmitter is guaranteed up to maximum working pressure. This kind of changes the dynamics of the operation with a transmitter that has that kind of stability, so very, very different to have a technology where stability is guaranteed right to the maximum working pressure. 

 
[07:14] - Tony 
And this is something that the user would have to determine which technology is best suited for the application. 

 
[07:21] - Sean 
Thank you, Tony. Look, I think certainly within some of the other continuous industries, you know, that type of stability is is going to be critical, but it's even more so now as we move into other industries where productivity is being measured to the nth degree. So that's that's fantastic responses on there Tony. One other myth that we've got amongst you and yours is, is that pressure transmitters is that they're actually very simple devices that have very limited diagnostic capabilities. 

[07:51] - Sean 
What would you say to those who say that transmitters are not really smart enough? 

 
[07:56] - Tony 
Pretty interesting question there, Sean. In the days of transmitter technologies where the majority of transmitters have a significant amount of diagnostics in-built into the designs, I have had to take the example of a Yokogawa pressure transmitter going back to the late 80s. The diagnostics was very limited. And in fact, the diagnostic display on the transmitter would be in some form of a code as an error code. In today's technology, the transmitter actually gives you a descriptor which will guide and steer the operator into the direction of possibly where the root cause of the problem might be. 

[08:33] - Tony 
However, embedded in this technology is higher diagnostics that is recorded in the microprocessor. This, however, is only accessible by the OEM that can then be utilized to assist the operator with diagnosing what the potential error could have been caused by and effectively then with operations, work towards a solution to try and negate the effects or cause of that event. And that would then hopefully assist them in circumnavigating some of the technical problems and challenges which very often the operator or the maintenance crew would not have any idea of. 

[09:15] - Sean 
Thanks, Tony. We've actually covered quite a few very important topics of the previous podcast and on this one as well as we move towards the end of today's podcast, is there anything else that you'd like to add to this episode or any other comments or experiences you'd like to share? 

[09:33] - Tony 
Well, yeah, I've had a few interesting ones where we've gone around and looked at some of the challenging applications in some of the mining situations, and we do a little bit of training with the boys and give them a bit of insight into what the technologies can do and what it's all about. And quite often you have some interesting questions that come from the floor. One of them being why is Yokogawa transmitters green? So for this young man, I looked at it and I said, you know, if you look at it, green is a very soft colour. 

[10:06] - Tony 
It blends in with nature. So in the background, the Yokogawa with the R&D looked at the subtle green color and identified with it very much like the military, almost like a camouflage. And the dynamics of it was that it's very soft on the eye. So that's one of the key reasons why Yokogawa transmitters are green. Well, the events that occurred after that was this man ran off to his engineer and said, that's it. I found out why Yokogawa is green. 

[10:36] - Tony 
They’re soft on the eye. And you can you can think what the engineer's response to that was. So we had a good laugh afterwards. And I informed the young guy that it was just one of my little quirks on the covered selection of Yokogawa transmitters. Nothing to do with that, but it's just our unique, dynamic colouring of our devices. 

[11:00] - Sean 
Thanks, Tony. Thanks very much for your insight. Look, it's been really good to hear you debunk these these misconceptions and actually share some of your experiences for that for the many years that you've you've you've had in the industry. And we do expect to have you for future episodes of Yokogawa Debunks as well. So thank you very much for your contributions, Tony. 

[11:22] - Tony 
Thank you, Sean. I appreciate the the opportunity to share some of my experiences and hopefully that can be used by some of our users out in the field. Have a good day. 

[11:34] - Sean 
Thank you, everybody, for joiniung. That brings to end this episode. And yet again, we look forward to seeing you next time. Thank you very much.