Completing CIS Surveys with MicroMax Current Interrupters & FDC – Virtual Brew 4/17/25

This Virtual Brew webinar we covered how to effectively set up and utilize the MicroMax line of current interrupters for your interrupted surveys. We explore the practical steps for setting up your MicroMax interrupter and waveform verification.

Transcript

Introduction

Lon
Welcome to this month’s Virtual Brew. We’re going to talk about the Micromax interrupter, and then go into the different CIS survey modes. So, we’re going to look at some of the hardware of the Micromax — mainly the Micromax 360, but the 300 is included in this as well — Micromax settings, as far as universal settings for getting your interruption set up for your surveys. And then we’ll look at close interval survey methods — there are three survey methods you use with interruption.

Micromax Hardware

So the first thing I’ll talk about is our Micromax interruptors. We currently have the Micromax GPS 300 — this does not have a relay attached, it’s used to drive an external relay, which could be solid state or mercury, either one. The Micromax GPS 360 has a battery built into it, and this can provide up to 60 hours of interruption. It also has an attached solid-state relay that can interrupt up to 100 amps, and it can be used with an external relay as well — we’ll talk a bit more about that in a bit.

So, the first thing you’re going to need to do is get your GPS — this comes with a GPS antenna, it’s magnetic, so you should be able to set that on top of the rectifier. The GPS is where we get our pulse-per-second, and that pulse-per-second is read by every other interrupter out there — it’s also read by the field data collector, in the DVM, so that everything can line up and you’re synced when you’re ready to do your interrupted survey.

Powering the Interrupter

So, hooking up either the 300 or the 360, you’ll have a pigtail with two alligator clamps on it. These can be hooked up to the AC taps on the rectifier — as long as you can find, between any two of the taps, 8 to 42 volts AC, you can hook that up, and that will power either one of the Micromax interruptors. If you have a DC source — coming off a battery, say — you can do the same thing, but there we’re looking for 10 to 60 volts DC.

At the end of that pigtail, which also has the input for power, there’s an output you can use to run an external relay — solid state or mercury, either way — that output is 10 to 14 volts DC, to drive the relay open and closed.

Now, if you’re going to power an external relay with the GPS 360, you’ll need to make sure it’s powered up — connected to the taps, or connected to a DC source. If you’re running it strictly off the battery, you cannot power an external relay.

Relays

The two different relays we supply — these are the main relays that are out there — you have a mercury relay, we have a 68 or a 100 amp. This is a mechanical relay — of course, it has to be installed vertically, or it will not work. There’s mercury inside, and a little electromagnet that opens and closes those contacts. Now, if you’re using a mercury relay, these are not recommended for cycles shorter than three seconds on, one second off — over time, that mercury relay can degrade, and you can get some chatter, some noise in there.

Our current solid-state relay is the 2510 — this can interrupt even low-voltage rectifiers, and it supports a fast cycle, so you can do subsecond — you can do a .08, .2, .3 cycle on there, you can do a one, one-and-a-half for your on/off as well.

Antenna and Satellite Status

Now, when you first power up the Micromax, on the screen you’re going to see some data, some info for you. The first thing is the antenna status — this is going to be open, short, or okay. If you don’t have an antenna hooked up, it’s going to be open. If there’s a kink in that wire — maybe a cow’s chewed through the coax — you could have a shorted antenna. And then you have an antenna status of okay, which means everything’s good.

You also have the satellite status — if it says ACQ SAT, that means it’s waiting to acquire satellites. Once you have satellites, it’ll show as 3D fix, and you’ll see the number of satellites it’s currently seeing. You also have a unit status, down at the bottom — you could have “check antenna” if it’s open or shorted, and it’ll give you your UTC setting — that’s your time zone — if it’s waiting for that 3D fix, that’s when it’ll show that, and it can also show whether it’s waiting for its leap second to get updated.

Output Parameters (Universal Settings)

Some of the things on the output parameters — these are universal parameters. This is the first thing you’re going to set, and once you set these, you can just leave them — they’re independent, they cover all of the interruption cycles.

So, if we go to Options and Output Parameters, you can set your switch — in this case, normally closed. If you use the wrench to change that, it just toggles between normally open and normally closed — most of them should be normally closed. Your cycle begins with — in this case, it’s on/off; if your cycle begins with off, you just change that, and it’ll toggle over to off/on. You have your UTC offset, which is where you’ll set what time zone you’re in — that’s pretty simple. We also have zero crossing, which helps prevent some of the breakdown that can be caused by transients, by induction — we’ll talk about that on the next slide. And then, number eight is Factory Default, which sets everything back to the factory default.

Zero Crossing

Zero crossing just means that when the AC crosses over the zero line, that’s when it’s going to either open or close the relay. What this does is help dissipate the power quite a bit when it’s at that zero crossing, so you don’t have all that inductance in there when it does its switching.

Now, I will say this could cause a delay of about plus or minus 4 milliseconds — if it’s somewhere in there, it’s going to wait till it gets to that zero crossing, which is about 4 milliseconds, if you’re looking at a total cycle of about 16 milliseconds for the full cycle at 60 hertz. This helps protect the relay and components.

Some of the icons up at the top will let you know if the power is connected, if you have a 3D fix, the number of satellites, and — if you have the GPS 360 — it’ll give you a battery status as well.

Programming an Interruption

So, for programming, we’re going to select one on the programming for interrupt — we’ll select which program we want, here, in this case, maybe select three. Three is defaulted to three-on, one-off. Four is defaulted to four-on, one-off. Now, these can be changed — all you have to do is change them, and you can set whatever you want for that on/off cycle.

You also have options here — you can do continuous, or you can do stop/start. In this case, we have stop/start — it’s going to start at 6:00 a.m. on March 2nd, and stop at 6:00 p.m. on March 10th. So every day, it’s going to do that in between those two dates, and then it’ll shut off, and your CP system will just be constantly on.

Verifying Interruption in the Field Data Collector

So, verifying interruption in the field data collector — of course, we’ll go to the DVM. I’m sure you’ve seen this slide multiple times, but this is extremely important — when you’re going to start your interrupted survey, this is the first place you want to go. Make sure you’re starting here, and getting everything in sync, all your settings correct, so you’re getting accurate on and off readings.

So, looking at the waveform inside the DVM — the gray area is the on portion of the cycle, the white area is the off portion of the cycle. Up at the top and bottom, there are tick marks — each one is 1 second. In this case, we’re looking at a total of eight seconds, and we’re doing a one, two, three on, and one off. What I like to do — if I’m doing, say, three on, one off — is set that to eight, so I see two full cycles on my screen as it goes by.

And, of course, we’re going to set up our on setup, which, in this case, is 100 milliseconds before the on-to-off transition. And we’re setting our off delay to 125 milliseconds after that on-to-off transition — that’s where we’re going to record our instant-off reading. And then, our cycle begins with the little shark fin at the bottom — in this case, our cycle begins with on, because it’s starting in the on portion of the cycle.

CIS Survey Methods: GPS Sync

Now, the first method we’ll look at is on/off GPS sync. GPS sync is what the majority of surveys are run as — this will sync up with the satellite, so the satellite timing, the Micromax, and the field data collector’s DVM are all synced up on that same time.
So, you’re going to set up all your interruption, get ready to go — your cycle begins with, and everything should be synced up. In GPS sync, if you look at your readings as you’re taking them, this is what you’re going to see: you’ll see an on reading in the first column, and an off reading in the next column.

And to note on this — if I’m doing a three-in-one cycle, I’ll get a new on/off pair every four seconds, because it’s going to get an on/off pair, and then wait again for the next cycle to get another on/off pair. So, you’ll notice here we have a change in our off reading, and then a change in our on reading — these are going to be the same for, in this case, four seconds. If you’re doing a four-in-one, of course, it’s going to be five seconds. If you’re doing a .08.2, it’s going to be every second — you’re going to get a new reading.

CIS Survey Methods: GPS Real Time

Next thing to look at is GPS real time — the settings are slightly different, and we have an extra GPS real-time setup time on here. This is used for longer cycles — three-in-one, four-in-one. If you’re doing an eight-second-on, two-second-off — for any type of reason — you’re not going to get a new on/off pair except every 10 seconds. So, every 10 seconds, you’ll get that new on/off pair.

So, to look at this — what we’re doing here is we have our real-time on delay. What that is, is after the off-to-on transition, that’s where we’re going to set one of the sides of our window. We also have a real-time off delay — so, in this case, 100 milliseconds into that off portion of the cycle is where I’m setting one half of my window.

Now, we also have a real-time setup — this is, each time before both of the transitions, how many milliseconds before those transitions am I going to set the other side of my window. What I’m doing here is creating a window that has the transitions — from on to off, and off to on — inside it. And if a reading is triggered inside that window, it knows it’s in transition, and it’s not going to record that reading — it’s going to record the last known good reading. So, if a reading comes in during this transition from on to off, it’s going to record the last good reading. Same here — if a reading comes in during the transition from off to on, it’s going to record that reading. As readings are triggered anytime outside this window, it’s just going to give you that reading — so it’ll give me my on, then it’s going to give me offs, and then it’s going to give me ons.

And this is how it’ll look when you’re running that survey — you’ll see I have an on reading, I have off, on, on, off — and each of these readings are different. These are not matched on/off pairs — these are live readings, as they’re triggered. So I’m triggering it in the on portion of the cycle, and I’m triggering it in the off portion of the cycle.

Q&A

[Moderator]
Hey, Lon, we have a couple of questions.

Lon
Yes.

[Moderator]
Cole mentioned — hey, how many people today are using the Micromax interrupter? So if you are, I’d suggest dropping a “yes” in the chat. And then we had a question from Casey: is that to keep us from recording spikes? And we have one more question after that as well.

Lon
So, as far as the GPS real time — what that’s keeping you from doing is recording anything that’s in a transition. So if I record a reading right in the middle of the transition, I know that reading is incorrect, because it’s in the middle of a transition — in this case, it could be around, you know, one volt, if I record it right there, and that’s not a good on or off — that’s not a true on or off. This is just keeping you from recording anything inside of that transition.

Now, as far as the spikes you’re talking about — you’re talking about anodic spikes, I’m sure. Let me back up here — this is where, in GPS sync, you are going to record. If I had an anodic spike here, I’m just going to move this off delay out until I’m past that anodic spike, and then I’ll get my true instant-off reading — my true polarized potential.

Is there another question?

[Moderator]
The other question was from Charles, and he asked: what are the delays for the previous GPS mode?

Lon
The previous GPS mode — GPS sync? Is that what you’re talking about, Charles?

[Moderator, relaying Charles’s confirmation]
Yes — yeah, he said.

Lon
So, the on setup — if you think of setup, setup is anything before something happens. So, in this case, I’m 100 milliseconds before that on-to-off transition. And then, any type of delay — that’s 125 milliseconds after the on/off transition. So that’s where that delay comes from. As far as GPS real time — both your on and off delays, and your real-time setup, is a setup, so it’s before that transition. I hope that helps.

High/Low Mode

Another thing to talk about is high/low. So there’s also a method called high/low — this is used if you don’t have GPS, or if you’ve lost GPS, so you can’t get a synced reading. What it does is it takes the total — it looks at all of the samples of your total cycle. So, in this case, if I’m doing four-in-one, I have 300 readings, because I’m reading at 60 hertz, which is 60 times per second. It takes those 300 readings and sorts them from positive to negative.

Then I have my delay set up for so many milliseconds — what that’s going to do is remove so many readings. So, for every 100 milliseconds, it’s going to remove six readings.

This is a good way to remove the spikes if I don’t have GPS sync, because I can eliminate all of the more positive readings on that anodic spike.

Now, something to be aware of here is that, in high/low, it’s going to assume your more negative readings are your on readings. So if you have an inversion, it’s going to mask that — this can also mask any type of interference, because it’s just going to take all of those readings and sort them out; it doesn’t know about any type of interference.

So, when we’re looking at high/low, we just look at the delays — and this is how that works. I have an on portion, an off portion, and an on portion. If I set, say, my off delay to 500 milliseconds, that’s going to eliminate 30% of the more electropositive readings, and that’s going to record my off reading at this point—