Remote measurement of pipe size

pipe-mic. never used one. clips to bottom of level rod

Cool, thanks. Looks like it could get messy though.

Yeah, its called a philly rod 😛

Beats climbing into the manhole (which everyone is fixing to jump you for even suggesting such a thing).

yep! OSHA's got this little thing called confined space entry. I have never entered a manhole to obtain pipe dia. By and large, you can usually eyeball the dia., but since you're already likely using a level/philly rod to get inverts, get top of pipe too - problem solved. there are standard sizing charts for pretty much any manufactured pipe out there, so just subtract out the pipe thickness as needed(only RCP typ)

I'd try it with a disto-mat, shoot the bottom then the top of the pipe... $100

You could low-tech it and take a lath and twist it around in the flowline of the pipe and measure from the score to the bottom like the rest of us do.

🙂

You must have some long lath.

> You must have some long lath.

That's what she said.

Seriously though, have you considered using midgets for this type work?

Low cost version - a steel builders square and a roll of duct tape to attach it to the rod. Measure the invert, then the top and subtract. Remember to compensate for the 2 inch width of the squares "leg".

We used to use an old worn-out fiberglass rod that wasn't good for running levels any more that we called our "sewer-rod". We would put fresh pain on the back of it and lower it down, and scrape the painted part against the pipe opening. We would then raise it and try to read from the bottom of the rod to the mark. Of course sometimes the pipe wasn't easy to "scrape" against, or the measurement wasn't always clear.

You don't have flagging to tie them together like we do?

Damn Snoop! That was good!

Eyeball the pipe and guess. Then tie a wrap of flagging around the level rod at the point you guess will correspond to the top of the pipe. Put the bottom of the rod on the invert to measure dip, check that your flag is at the top. Adjust flag if necessary. Confirm against measurements in connected MH's. Further confirm vs. GIS or other record data, when available.

That's a good one.

I've lost too many already.

> That's a good one.

If it's too deep and dark to see well- When the flagging is slightly below the top of the pipe you can lift the rod a little and feel the knot in the flagging when it catches the top edge of the pipe.

Didn't someone come up with a pole that held 2 prisms? You shot the 2 prisms and it would calculate for you, the XYZ at the end of the pole...

or

You could always hang your laser scanner upside down in the manhole....;-)

Cheers,
Radar

If you have some mad money to dispose of, just the tool you need for doing a lot of manhole readings...

Pipe-Mic