remote leak detection system

Hello everyone,

I'm doing a prototype for my Bachelor End Project about a remote leak detection system applied to a water supply infrastructure.

The main idea is to have a bunch of Arduinos reading moisture sensors and sending teh data to a server if there's a leak showing where's the leak.

I've never done a project involving data transmitting before and i find it very difficult to know which way i should go due to the massive amount of information there's on the internet. :confused:

I'm thinking about getting Arduino UNO + Ethernet shield with POE and try to build like a token ring with some hubs. (Let me know if i'm wrong please)

As i said it's a prototype, i'm going to use just 2 or 3 Arduinos just to check the data transmitting works properly.

I find Ethernet a good idea because the pipes are buried so a wireless connection wouldn't work.

I also go with PoE because i won't have to use any other cable to supply power.Easier and cheaper. That's an important fact when i extrapolate the results to a entire city infrastructure, for example.

I would like to ask you if you could give me some advice in which is the best way to go and how can i make it work, at least my 2-3 arduinos prototype.

Thanks for your time.

Regards, Alex

I'm thinking about getting Arduino UNO + Ethernet shield with POE and try to build like a token ring with some hubs. (Let me know if i'm wrong please)

Why does a "token ring with some hubs" seem like a good idea? Next time you are in a classroom, look around at all the computers. Do you see a "token ring with some hubs" anywhere?

I find Ethernet a good idea because the pipes are buried so a wireless connection wouldn't work.

Are you planning to dig the pipes up, to bury the Arduinos with Ethernet shields?

I would like to ask you if you could give me some advice in which is the best way to go and how can i make it work, at least my 2-3 arduinos prototype.

If I recall correctly, this is YOUR degree program's proof that you learned something. Having us do any of the work for you simply proves that you didn't.

If you have SPECIFIC questions, it is perfectly OK to ask for help/clarification/etc. It is NOT OK to ask us to do the project for you.

PaulS: Why does a "token ring with some hubs" seem like a good idea? Next time you are in a classroom, look around at all the computers. Do you see a "token ring with some hubs" anywhere? Are you planning to dig the pipes up, to bury the Arduinos with Ethernet shields? If I recall correctly, this is YOUR degree program's proof that you learned something. Having us do any of the work for you simply proves that you didn't.

If you have SPECIFIC questions, it is perfectly OK to ask for help/clarification/etc. It is NOT OK to ask us to do the project for you.

I'm studying Industrial Engineering and I've never seen anything related with telecommunications. This is not a proof, just a project and i'm trying to go further adding the monitorization part.

I've been trying to find a way to solve this for 3 weeks (Looking for similar projects, asking friends, visiting different pages) and every new page I visit I find something new.

I'm not asking you to do my project, obviously not. Just a guidance because it's impossible to have specific questions when i'm finding out new stuff everyday.

Keywords (Like the name of a protocol or... whatever) would be completely fine to me. I just need for someone with experience to give me a way as there're too much info on the internet.

However, thanks for your comments about the hubs and the token ring. I could read between the lines it's not a good option.

I find Ethernet a good idea because the pipes are buried so a wireless connection wouldn't work.

The pipes may be buried, but that doesn't mean all your electronics has to be. How are you going to power it?

What range do you need? Metres ? miles?

Ethernet is a very fast comms medium - the amount of data you need to send is very small.

Keep thinking!

Allan

You talk about 1-2 Arduinos, with moisture sensors, to detect leaks. That should be very specific and predetermined locations, and sounds very much like monitoring a place and alarming when there are leaks, rather than searching for leaks along a pipe. Otherwise the person digging up the pipe could check for the leaks himself, no need to use an Arduino for that.
How big are those pipes?
How big do you expect the leaks to be?
How are you going to be sure that a good rainstorm is not mistaken for a leak?

Big leaks in big pipes (water mains: half a meter or more in diameter, many kilometres long) are searched for in a very different way: acoustic. Basically they take a probe, shove it in the pipe at one end, let it go with the flow and listen for leaks (leaks tend to make sounds in the water, especially bigger leaks). Then at the other end it’s recovered, and the time when the leaks are heard give a good indication on where exactly the leak is. After that it’s a matter of driving to that location and bringing out the diggers.

Much more efficient than digging up the whole pipe and placing sensors every half metre (you maybe can get away with a bit fewer but it’s still a lot of work).

Much more efficient than digging up the whole pipe and placing sensors every half metre (you maybe can get away with a bit fewer but it's still a lot of work).

You need to keep in mind that the pipes are usually buried in gravel, and that storm water runoff also finds its way into that gravel, so the fact that there is water outside the pipe does NOT mean that the water came from inside the pipe.

allanhurst: The pipes may be buried, but that doesn't mean all your electronics has to be. How are you going to power it?

What range do you need? Metres ? miles?

Ethernet is a very fast comms medium - the amount of data you need to send is very small.

Keep thinking!

Allan

Hey Allan,

You're right! i'm working with 12 meter long premade pipes.

I integrated a sensor in every segment of pipe so i have a reading every 12 meters. Every sensor goes to a pin of the Arduino. So, I need an arduino every 100 meters more or less.

My first thought was to integrate the arduino too and try to build like a "plug and play system". The only part that would lay on the surface would be a solar panel to power the Arduino. But I found the PoE option and I was wondering if it would be useful. It'd make it even easier to assemble.

I appreciate your help!

wvmarle: You talk about 1-2 Arduinos, with moisture sensors, to detect leaks. That should be very specific and predetermined locations, and sounds very much like monitoring a place and alarming when there are leaks, rather than searching for leaks along a pipe. Otherwise the person digging up the pipe could check for the leaks himself, no need to use an Arduino for that. How big are those pipes? How big do you expect the leaks to be? How are you going to be sure that a good rainstorm is not mistaken for a leak?

Big leaks in big pipes (water mains: half a meter or more in diameter, many kilometres long) are searched for in a very different way: acoustic. Basically they take a probe, shove it in the pipe at one end, let it go with the flow and listen for leaks (leaks tend to make sounds in the water, especially bigger leaks). Then at the other end it's recovered, and the time when the leaks are heard give a good indication on where exactly the leak is. After that it's a matter of driving to that location and bringing out the diggers.

Much more efficient than digging up the whole pipe and placing sensors every half metre (you maybe can get away with a bit fewer but it's still a lot of work).

I'm using 2-3 Arduinos on the prototype. Just to prove it works and it's possible to know where's the leak. i should be able to extrapolate that to a whole city infrastructure for example.

I'm talking about premade pipes of 12 meters long and a diameter of 0,5 meters. This system will be integrated in the pipes and it won't be applied on the actual infrastructure. So there's not need to think about digging up pipes.

The idea is to be able to detect really big leaks. I mean, after doing some research, about the 20% of the water is leaked. My are not subtle leaks. And it doesn't matter if it rains, I ignore the readings for a couple of days until the soil dries again. Extreme accuracy and fast reactions are not necessary this time.

And yes, i know the acoustic way but it's not useful here as i work with wastewater and this method works fine with high flow or pressure pipes.

Thanks a lot for your interest!!

PaulS:
You need to keep in mind that the pipes are usually buried in gravel, and that storm water runoff also finds its way into that gravel, so the fact that there is water outside the pipe does NOT mean that the water came from inside the pipe.

It really doesn’t matter. I’m not aiming for high accuracy and fast reactions. I just want to be able to detect big leaks that last so many time

Thanks!

20% leakage only? Not too bad. It being low pressure of course helps to lessen leaks.

I'm really at a loss on how to detect leaks using moisture sensors. Maybe some form of conductivity sensors, but soil will never dry out unless you're in the desert.

If placed under the pipe (where the leaking water goes) you may even make use of the rain: leaks are where the readings don't change (as it's saturated already).

If most of the leaks are at the joints (i.e. every 12 meters) you'd need a device there, not in between. To collect the data, you could send a probe down the pipe on a weekly basis or so, when in range of a monitoring station it wirelessly takes the reading (you should be able to make it work through a concrete pipe), then at the end of the pipe recover it and read out the data.

Then you have the problem of power supply: batteries run out, and you'll want to have it work "forever" I suppose. That would probably mean installing power cables. If so, your communication problems are also solved: just add another few wires, and talk to your stations over RS485 or so.

You'll also want to make it all really really robust as replacing a failing unit is so expensive!

wvmarle: 20% leakage only? Not too bad. It being low pressure of course helps to lessen leaks.

I'm really at a loss on how to detect leaks using moisture sensors. Maybe some form of conductivity sensors, but soil will never dry out unless you're in the desert.

If placed under the pipe (where the leaking water goes) you may even make use of the rain: leaks are where the readings don't change (as it's saturated already).

If most of the leaks are at the joints (i.e. every 12 meters) you'd need a device there, not in between. To collect the data, you could send a probe down the pipe on a weekly basis or so, when in range of a monitoring station it wirelessly takes the reading (you should be able to make it work through a concrete pipe), then at the end of the pipe recover it and read out the data.

Then you have the problem of power supply: batteries run out, and you'll want to have it work "forever" I suppose. That would probably mean installing power cables. If so, your communication problems are also solved: just add another few wires, and talk to your stations over RS485 or so.

You'll also want to make it all really really robust as replacing a failing unit is so expensive!

Yep, 20% that's what i found (At least in Spain). It's not that bad if you're talking about fresh water but it's an environmental problem when talking about wastewater :/

The sensor i use is this one: https://www.tindie.com/products/miceuz/i2c-soil-moisture-sensor/ It's covered by heatshrink and i coated it with epoxy.

With this sensor I can distinguish a leak even though the soil is not completely dry. More moisture gives me higher reading.

Thanks for sharing your thoughts! I'm gonna google RS485 and try to learn as much as I can about it :)

I've heard numbers of 30-50% for drinking water (that would be pressurised pipes, making leaks worse fast).

RS485 is a serial protocol designed for long (very long) lines, and to handle multiple drops on the same line - in contrast the better known RS232 is designed for peer to peer only. Not fast, around 1200 bps is normal, but that should be more than enough for your application.

You're underground so I'm afraid wired is the best way to get your data out.

wvmarle: I've heard numbers of 30-50% for drinking water (that would be pressurised pipes, making leaks worse fast).

RS485 is a serial protocol designed for long (very long) lines, and to handle multiple drops on the same line - in contrast the better known RS232 is designed for peer to peer only. Not fast, around 1200 bps is normal, but that should be more than enough for your application.

You're underground so I'm afraid wired is the best way to get your data out.

Okay, i see. Thank you so much!

Since you need reasonable ranges : >10 metres

and very low data rates - might a reading twice a day be adequate?

You could

either combine your signalling and power lines in a single cable, but because of the range use a differential technique for data to reduce noise : RS422 etc. Lots of wiring.

Or make radio coupled devices which sleep most of the time, taking uA or less, and report their measurements via a RF link . A a 'daisy-chain' type polled protocol could work here with large ranges to a central data collection point.

A primary cell could last for many years in this application.

Loads of options

Allan

How to make them wake up at the same time as their peer to do the transmission? You don't want to have them sit and wait for long time.

Here is another thought. In the US, and probably other countries as well, all buried non-metalic pipes must have a trace wire laid along with the pipe. The ends of that wire must be available so a detection system can trace exactly where the pipe is buried. There is nothing to restrict you to a single strand of wire. A multiple conductor could be used to power and control your system. It would have to be removed when the pipe tracing was being done.

In addition, since you will have no access to the equipment, you need to use what you learned in your classes about failure analysis and design in modes that allow your system to still function when pieces fail.

Paul