Thinking About Building Something That Can Detect Poly Pipe

what about using sound to detect cavities?

Hello canderous ordo

Ground Searching Radar will do the job, and highly accurately, you won't probably be able to build it yourself, and it won't be cheap for some equipment to penetrate 200 metres depth as you are asking.

Why is the pipe buried some 200 metres below the surface?

Kind Regards....

Good question. That likely is in a mountain. Want to bet its military?

j.

I use metal rods to find underground clay and plastic pipes and its very accurate. The devining rods are made from an old metal coat hanger, (you get them from dry cleaning shops) and they swivel when walking across the line of the pipe. I appears to be activated by sensing a void under the surface as they also found a small cavity under my garden lawn! Not sure how they would work with pipes under concrete but they detected a soil pipe over a metre below a gravel drive.

I have shown this method to many people and most are able to get the hang of using the rods within a few minutes. Why the devining rods work is a mystery to me - perhaps it would made an interesting discussion topic and might have useful spin-offs if we can make a 'machine' version.

Don't need the divining rods. They work because they are representative to the holy spirit as a prayer device.

All you really need to do is prayerfully walk across a field and the holy spirit will bless you with that special feeling when you cross whatever it is you are looking for.

No! Really! Just try it!

j.

Let me know how your thinking turns out.

Plastic pipe really does need an identifying wire from what I know.

Two meters is deep.

You might calculate the back pressure expected of your fluid and determine what it would be if working, and then calculate the pressure expected against what you are getting to determine the length of the run before failure, and then dig there.

anyway, let me know what the solution is since I have to dig holes in the ground a lot, looking for plastic pipes. I've come to want a Megger meter too.

There is equipment to detect burried (non-metalic) mines. But I doubt that it would detect a plastic pipe over 2m below ground level. If you can get at the pipe at some point perhaps a sound signal can be injected into the pipe and then listening devices could pin point the location of the pipe elsewhere.

Reading through the thread, the previous answer comes close.

I was going to suggest putting "bubbles" into the fluid and using a listening device (stethoscope) to trace the sounds. Low tech, low cost and if it doesn't work, then little lost.

If you know the depth, then you could use "doppler" method providing there was fluid flowing in the pipe. In a past life, we made dopplers to measure blood flow in arteries, but the principal would work. You would detect a distinct change in reflected signal frequency when the flowing media was in the reflecting zone.

Basically, "broadcast" a tone into the ground at 45 Degrees and have a receiver such that signal penetrates ground, impacts flowing material and is reflected back to receiver. Simple headphones like metal detector and listen to the tone.

Other idea is to "inject" electrical signal (like the phone guys use to track a line) into the contents of the pipe and sense that the same way the phone guy does.

The other (obvious) idea is to "look for the wet spot" that's where the leak is.

At 200m underground, you probably need to insert someting inside the pipe and detect from there.

There was also a thread talking of finding/fixing leaks under a concrete slab in a refrigeration plant. There might be some fresh ideas there.