Calculating AC Current Density with Triton Coupons: Virtual Brew 12/05/2024

In this episode of Virtual Brew, our free monthly webinar, Remote Monitoring Specialist Michael Plaster walks you through the best practices for managing critical AC current density calculations and ensuring accurate compliance measurements. Plus, learn how to use the Triton Triple Coupon Test Station to streamline your process and improve results.

Resources from this episode: Download the PDF guide for a walkthrough of the content covered in this episode.

Transcript

Introduction

Michael Plaster
As he said, my name is Michael Plaster — I’m the remote monitor specialist. To get started, I hope everybody had a good holiday, and let you know: my family told me no more dad jokes over the holiday. Well, I can’t stop cold turkey — so they’ll get better from here.

All right — our agenda today: why does AC matter? AC coupon sizes. We’re going to talk about getting your current density off your Bullhorn RM4210 or RM4250, and then manually calculating the AC current density with your Triton and Triton coupon.
Why AC Matters

So, why should we care about AC? Well, prolonged AC interference will rapidly accelerate corrosion on your pipeline. Exposure to unmitigated AC currents can cause damage to coatings and metal loss, and high induced AC voltage presents a shock hazard to pipeline personnel.

If that’s not enough, there are regulations on it — PHMSA 192.473 has been modified to reference AC interference, as well as the Mega Rule. So, for the regulations, each operator needs to have a plan that will effectively minimize the stray current on your pipeline, and also correct any instances where it’s greater than 100 amps per square meter. But then the kicker is, they also say it applies if it impedes safety operations on the pipeline, or adversely affects the environment or the public — so that leaves it a little wide open there.

AC Monitors and Triton Coupons

So we’re going to go ahead and get started by talking about our remote monitors a little bit here. Our RM4210 is our satellite version of the AC monitor, and our RM4250 is the cell version of the AC monitor. These will monitor your native coupon, your reference cells — you’ll get your AC current density, you’ll be able to get your pipe-to-soil, and you can also use our Triton test station, or our Triton coupon. One of the advantages of using them all together is the ease of installation — it’s all color-coded, easy to get installed, pretty much plug and play.

Now, the most common question we get in support on our AC monitors is, how do I install my remote monitor? No — that’s not it. It’s, how do I manually read AC current density? Because we made it pretty easy to do the install of the AC monitors — the question that comes afterward is, how do I verify the readings I’m getting on the Bullhorn unit? And that’s what we’re here to talk about today.

Coupon Size

So, first thing you need to know is your AC coupon size that you have out in the field. We commonly sell a 1 cm², a 10 cm², and a 1.4-inch-squared coupon. So which size should you use? Well, the standards don’t specifically tell us, but we suggest the 1 cm². The reason for that is you want to use a smaller coupon to take that AC current density, because as you get into larger coupons, such as 100 cm², there’s a spreading resistance, and over time that makes your manual reading a little bit inaccurate. So you want to use those smaller coupons, and you need to know the size of that coupon.

I’m going to stress that several times throughout this presentation, because we get a lot of questions on how to calculate the AC current density, and when we ask what your coupon size is, and the answer is “I don’t know” — well, we can’t do that, that’s part of the calculation. So we have to know that coupon size.

For testing your current density, the first thing you need to do is have something to compare it against, and that’s your Bullhorn reading. So when you go out to the field, you’re going to swipe it with a magnet to open up the Bluetooth on it, and then you can open up Bullhorn Tools. Bullhorn Tools will take a reading on it, and you can get your Triton AC current density. The reason you want to do this before you take your manual reading is, if you go off a reading you had on Bullhorn Web from a month ago, a week ago, even yesterday, it’s not going to compare to the reading you take today. Your current density can change hour by hour, and sometimes minute by minute, depending on the current you have on the pipeline. So you need to compare apples to apples — take the Bullhorn reading with Bullhorn Tools first.

Taking a Manual Reading

All right, now, in this scenario, we’re going to show you how to take a reading manually. The first thing you’re going to do is disconnect the RMU — this will take out any of the impedance combined between the voltmeter and the RMU. Then you’re going to hook up your DVM to the AC coupon on the structure. Once you’ve got that hooked up, you’re going to flip the switch to open — the reason you want to do this is to avoid interference from the DC coupon, if you’re hooked up to it. You’ll see your reading change when you flip it from closed to open. The reading you get when it’s open is the reading you want to use for your calculation — once again, it needs to be open. And, as I said, I’m going to keep stressing this: know your coupon size.

Calculation Scenarios

All right, now we’re going to go through several scenarios here. Our first scenario is manually calculating the AC current density using a 1 cm² coupon. Our manual reading, we’re going to keep consistent through all these scenarios — 27 milliamps, and a coupon size of 1 cm². We’ve got our formula written out for you, and if you don’t want to write it down now, we’ll provide the presentation for you later, so you can get that formula, as we plug in our information there.

We’re going to start with our manual reading over the coupon size, and get down to step four — it’s going to be your 27 times 10, which equals 270 amps per square meter. You’re really cooking on your pipeline right there — but we’re going to come back to this reading in a few more slides, and move on to our next scenario.

But before we do that, I want to tell you about the knock-knock joke. The guy who invented the knock-knock joke should get a Nobel Prize. All right — and I said they would get better.

All right, we’re going to move on. Our next scenario is 10 centimeters squared. We’re going to change it up a little bit — our 27 milliamps, we’re going to convert that to amps, so it makes the formula flow a little better — you could leave it in milliamps if you want. Once you get down to step four, it’s going to be .0027 times 10,000, which gives you 27 amps per square meter. So, big difference — same reading, between two coupon sizes.

Ryan Simpson
Is the AC coupon normally connected to the structure with a Triton configuration during — when we take a reading?

Michael Plaster
It’s — that’s when we connect it up. Other than that, it’s disconnected up until the time we take our reading.

All right, in our third scenario, we’re going to use a 1.4-inch-squared coupon, and this one’s a little more involved, because we have to convert the inches to centimeters squared — and I’ve got that here in our formula, already calculated out for you, so you don’t have to do that in the future. So we’d put our 27 milliamps over the 9.032 cm², and when we calculate that out, what we’ll end up with is 2.989 times 10, which gives us 29.89 amps per meter squared.

So, three different scenarios — and I want to simplify all this for you, so you don’t have to always run through all of these calculations. It’s pretty easy to do: if you’ve got a 1 cm² coupon and take a milliamp reading, you multiply it by 10, and that’ll give you your current density. If you’ve got a 10 cm² coupon, you just take your milliamp reading — it’s one to one. So if you’re taking a microamp or amp reading, just convert it to milliamps, and it’s a one-to-one scenario. For your 1.4-inch-square coupon, it’s a little more involved, but not too much — you take your milliamp reading, divide it by that 9.032, times 10, and that’ll give you your amps per square meter.

But if you look at these three coupons, we got three different readings for the same milliamp reading to start out with — so that’s why coupon size is very important. If you don’t know your coupon size, or you guess at it, you could have a reading that’s way off. If you think it’s a 1-centimeter and it’s actually a 10-centimeter, that could drastically change what you do as far as mitigation going down the line. So you need to know that coupon size.

Conclusion

All right, in conclusion — you want to start by checking your reading with Bullhorn Tools off your Bullhorn RMU, whether it’s a 4210 or a 4250 — you need to take that reading while you’re in the field. Don’t take that reading off Bullhorn Web from yesterday, last month, or last week — you need to have something to compare it to that’s apples to apples. And directly taking that reading off the Triton coupon will help eliminate your IR errors — that’s a lot of the questions we get about readings that are taken above ground and not using our Triton coupon.

And you need to make sure you flip that switch open to eliminate your DC interference — as I said, when you’re taking that reading out there, you’ll see a lot of times the difference between the closed setting and the open setting. And then you definitely need to know that coupon size — if you don’t know that coupon size, it’s going to change your reading.

Now, if you’ve got a Bullhorn RMU connected up to it and you don’t know that size, you can look on Bullhorn Web and see what it was originally configured with. But if it was something that was buried years ago by another technician, unfortunately, you’re going to have to find that paperwork on that coupon before you can calculate your AC current density.

Q&A

Michael Plaster
All right — any questions?

[Moderator]
Yeah, we have a few minutes left, so if anybody wants to unmute themselves or just post a question in the chat, we’ll be able to answer that for you.

Brad
I’ll jump in here — first of all, I’d like to tell you that your jokes are terrible, which makes them awesome. The question I have is: is there any way, or do you have plans to further automate the technology, so that — let’s say within the database — you’ll be able to populate the coupon size, and then, when you take the manual reading, it would automatically do the processing and calculation in the field, and give you your amps per square meter as an output?

Michael Plaster
That’s something we’re going to have to check with our product managers on — to see, because we are looking at doing some changes in the future, but I’m not sure if that’s going to be one of them. But that’s definitely something we can consider. We definitely have the coupon size on the website, so it’s something we can get to if we need to — and also, with Bullhorn Tools, as you dig into your channel settings, you can see that as well. But to add a script to manually calculate that reading — that’s something we can look at, because that could definitely see use in the future.

Brad, the other side is — if you guys are using — so, in PCS 2.1, we added all of the specific AC-calculated fields for field data collection, when you’re out on site. So the question would be, have those been activated on your device as well? Because that’s also where you’re going to see your coupon size, and it does do some calculation work — but it’s something we can take offline with you, just to make sure you have things activated, because sometimes that’s been missed. In the past, people had to use UDFs — user-defined fields — in order to build out some of these advanced calculations, which we did resolve back in, what, 2020? So maybe it’s something we can take offline and see if there’s a solution for you.

Brad
Okay — I’m a consultant, so I have different clients, so I don’t know what they have.

Michael Plaster
Yeah, I know that they’ve got certain things in their database system that they download into the field computers before they head out — but I don’t know what. So, a lot of times, that’s something you can call in and ask us, and then we can work with your end user to let them know what fields to physically activate for that inspection — which means you’ll see those populating on your data collection device when you’re out in the field as well. So anything we can do to help be a middle man, to get you the best fields in the data collection stuff, we’re happy to help.

Brad
Okay, thank you.

Michael Plaster
Right — any other questions, anything we can help answer? I think I see a couple of questions in the chat here — one from Ryan Simpson. Let me — no, Jerry actually was the first one who asked a question. He said it seems nothing changes when he flips the switch when hooked up to measure AC current density. And David Monroe also said he has the same issue as Jerry — when he toggles the switch, nothing happens. Is the AC coupon not connected to the switch? Do we need to swap the wires at this point on that one?

I’m going to have to check on what’s causing that — I know on low current it doesn’t really affect it, but I’d need to check and see what might be causing that on higher currents out there. And David, we’ll do a follow-up on any questions in this and send that to the group — we do that as a follow-up on anything inside this chat.

I also see — Nick, PCS 2.5, our new release, with some key more automation-based functions, is going to be releasing to the public on December 16th. So we do have the release notes, and we can send that out to this group as well — I’ll send it directly to you next, so I’ll take care of that on my side.

Looks like that’s all the questions we had in the chat — any additional questions, now’s the time to ask.

Jerry Whismer
I guess I’ll jump in — this is Jerry Whismer, I asked that question about nothing happening — and then Ryan Simpson, if you wanted to go off mute — is that you put — the AC coupon is not connected to the switch? So, if that’s true, that would explain why flipping the switch doesn’t change my readings. But does that mean flipping the switch is just what Mike was saying about reducing any DC interference that might be in the read? I just don’t feel like I’m getting good reads.

[Moderator]
Oh, go ahead, go ahead, Mike.

Cole
Hi, Jerry — I’m Cole, I’m product manager for Triton and Bullhorn and everything — I’m just hopping in here. Yeah, Mike — what Ryan said is correct, because when you flip the switch, you’re removing any DC interference on the AC coupon. So that’s why the AC coupon isn’t directly attached to that switch — that’s just removing any DC interference from the test coupon that we have on the Triton. So, since you have the native, the test, and the AC coupon, it’ll be removing interference from the test DC coupon.

Jerry Whismer
Thank you — that explains a lot.

[Speaker unclear — Michael Plaster or Cole]
Of course — Jerry, we can follow up with you to help with any type of thing. If you’re feeling like the reads aren’t reliable, we definitely have a lot of best practices there, and we can jump on a support call — but we’ll follow up with you directly after this as well, just to make sure we’re going to support you.

Jerry Whismer
Sounds good — that’s the main reason I joined this, was to figure out why isn’t anything changing when I flip the switch. So that explains a lot. Then I will call — I have put together a sketch of how I understand everything, all the way from when you order a Triton coupon test station, what it looks like when you get it, versus how you’re supposed to hook everything up with the RMU. And that little black cover that’s on the Phoenix cap, over the wiring harness — there’s a little black pin device that shorts wires one and three. I didn’t know, until playing around with things and figuring it out, that you have to remove that to season the coupons, and then put it back on if you’re not going to use an RMU. Does that make sense — do you know what I’m talking about?

[Speaker unclear — Michael Plaster or Cole]
Yeah, that definitely makes sense there — we’ve had a lot of questions on that in the past, and I can also send you the write-up we have on it as well.

Jerry Whismer
Beautiful, thank you.

Closing

[Speaker unclear — Michael Plaster or Cole]
All right, well, we’ll go ahead and start to close things down. Obviously, happy to answer questions — again, any questions you have, any need for support, always have your account manager, or [email protected] — we’ll be able to turn things around as quickly as we can to help answer, and always want to be a resource for you. So I hope you guys have a really great end of the year — we really appreciate all the effort and partnership throughout 2024, and are really excited for a really strong and great ’25. Thank you again, and hope you guys have a great end of the year and holiday season.

[Moderator]
Yes — and a couple of reminders before everybody jumps off: stay tuned for some more details on the 2025 Virtual Brew topics, we’ll be releasing those soon. We’re moving to a new platform, probably in January, but you’ll get some reminders on when that happens. We’ll send a follow-up after this — usually it’s on Monday, we send an email with resources, and we’ll send a copy of this presentation, so feel free to reply if you have any additional questions then as well. Thank you so much, guys — we’ll see you at the next one.