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Tim R[_2_] Tim R[_2_] is offline
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Default Diffferent techniques in troubleshooting

On Saturday, January 2, 2016 at 2:04:06 AM UTC-5, wrote:
"Another unrelated problem. You being an engineer will enjoy this one. The city has a water leak. They are not sure where the leak is. They can not dig up a whole city block to find it so they use a clever trick. They put two microphones about 50 feet apart where the leak seems to be. Then then record the random sound of water hissing out of the pipe. The two microphones are wired to left and right channel of the recorder. By adjusting the time delay of the right or left microphone they can find the sweet spot where the random noise from one microphone matches the random noise of the other microphone. Once the delay is know they know where the leak is within 1 or 2 feet. That is a clever trick. "


HA, HAHAHAHAHAH

HydroTDR


Hah, I can top that one.

We had a power outage, traced to a break somewhere in an underground line. It was one of those ancient coaxial feeders, and it ran a good quarter mile through the woods, maybe more, it's been a while. How to find the break?

We hired this specialist with a thumper, which is a pulsed high voltage DC. It makes a noise like a gunshot when the arc jumps the gap. You walk the route of the line (which you never know exactly because your drawings are always a little sketchy) and listen.

Usually this works. Not this time - it arced for a while, then somehow the arc welded the break back together. No more pulses, no way to find the spot, we just turned the power back on and let it go.