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Laser for Inverts
Posted by CT on August 22, 2021 at 1:18 pmHello-can anyone recommend a decent laser for measuring hard to reach pipe inverts? Thanks for any replies.
CT replied 2 years, 6 months ago 14 Members · 34 Replies- 34 Replies
I have a little Bosch handheld–GLM42 that I love. I would use it for manhole depths. Not sure it would be effective with any significant flow in invert… I gave a hundred bucks for it a couple years ago, and it has paid for itself many times over.
Look for a model that does “indirect measurement”. That is Bosch speak for correcting the slope distance to vertical (or horizontal) by applying a vertical angle.
I have the GLM42 and it is, hands down, the best method of doing measure downs I’ve ever hit on. And I’ve tried them all in 30 years. It will penetrate and couple of inches of flow.
I work for a water utility, so this is pretty well my day to day. Disto s910, combined with a rod that holds the disto at the MH centre. I will post a listing/design for the rod brackets today.
@mark-mayer Great! Thanks Mark!
@martin_au thanks Martin!
Be aware it is my experience that the liquids in the manhole channel will reflect the laser and give an incorrect reading, or more often an error message.
@martin_au A fellow s910 enthusiast, I see. Good little unit, worth every penny for so many uses.
The Disto is $1000 or more. The Bosch is around $100. Just sayin’.
@norman-oklahoma and the Bosch can??t do what the Disto can.
I measures the vertical to a pipe invert very nicely. For $1000, I expect the Disto to serve me coffee, piping hot. Damn fine coffee.
- Posted by: @norman-oklahoma
I expect the Disto to serve me coffee, piping hot.
While the manhole is still open?
I hope everyone has a great day; I know I will! It??s all fun and game until someone asks for pipe/mh chamber diameters. 😀
I tried several of the units mentioned, but ended up buying the Leica Disto X4 ($376 on Amazon). It measures the angle and slope and reports the calculated vertical. The Disto X3 does the same for $100 less, but the target viewer on the X4 is well worth the extra money.
@ct thanks. I see in ??official? descriptions that it somehow easily obtains horizontal distances. How do we get vertical distances in a manhole? Does it have some sort of internal plumb line? Or do we have to just roughly guesstimate a vertical plumb line and then record the angle to an invert that is recessed or offset inside a structure? I hope these are reasonable questions that make some sense. I think I have bought several devices from beer leg recommendations like this on Amazon (I have a Bosch too, but I think it only measures direct slope distances) then they go in a corner somewhere and get forgotten and never used. I do invert measurements so infrequently these days I forget about the tools (toys) and grab the poop stick out of extremely old habits when the time comes for one of those jobs.
@brad-ott Brad, the X3 & X4 measure the slope distance and angle to the shot, calculates the vertical (side b) and displays the lengths a, b & c and included angle. Works great for manholes & storm inlets where the pipe is offset so as to prevent a direct measurement. I wouldn’t trust it for a sewer line with moderate to heavy flow. Although if you know the pipe size you could take the shot to the top of the pipe and add the size to the reported side b measurement for the invert.
@brad-ott the specs can be found https://shop.leica-geosystems.com/disto-job-site-measuring-us#x4
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