Asking for a friend

Just loosen up those tolerances....

Bam! Solved!

I wonder what drives the requirement for 0.001 ft (0.3 mm) relative to outside.?ÿ It seems awfully tight for piping and tanks.?ÿ Even for points in a smaller area relative to each other it seems tight.?ÿ Perhaps for leveling corners of a machine, but not for connecting things together.

Posted by: @holy-cow

The project he is working on is the design to modernize a city water plant.?ÿ The existing plant was built about 1950 so will have roughly 75 years of use before the new project is complete.?ÿ He has quite a bit of real world experience in land surveying and construction staking.?ÿ His issue is how to carry bench mark data from outside into the maze of equipment inside the plant.?ÿ There are no "easy" ways to get from the ground into the main portion of the building without making some incredibly tight turns with short lengths.?ÿ His goal is to keep vertical data consistently within 0.001 feet for all of the various piping elevations.?ÿ What is the best category of level to use inside with relatively slick concrete floors and continuous vibration and noise??ÿ What is the best way to carry an elevation up about 25 feet from what is supposed to be a very solid bench mark to hit a spot on a landing where a set up can be made to start working inside the three story building.?ÿ Multiple attempts using standard total station set ups and prisms has varied 0.003 and more.

Ditch the level. By spatial analyzer and a laser tracker. Get training. He will be much further along. And will be able to use it to align machines pulleys etc. ?ÿThese things are made for working inside tight spaces. They can be mounted upside down sideways and anyway in between. I have used them for work and even incorporated them into survey workflows. They are used for many industrial uses. They work in 3d xyz where x and y are perp to z. So not a typical stake out. Or topo type thing. I had to use one to hold mount a 10ƒ?? x 10ƒ?? approximately piece of equipment for a testing. This thing was like a huge book shelf with parts all through it. So the mounted machined parts I would be able to see out in the field. I measured everything relative throughout this piece to less than 40 thousands of an inch. ?ÿThen aligned it on site to a different test item. Its the right tool for that type of job. ?ÿ

Posted by: @holy-cow

The project he is working on is the design to modernize a city water plant.?ÿ The existing plant was built about 1950 so will have roughly 75 years of use before the new project is complete.?ÿ He has quite a bit of real world experience in land surveying and construction staking.?ÿ His issue is how to carry bench mark data from outside into the maze of equipment inside the plant.?ÿ There are no "easy" ways to get from the ground into the main portion of the building without making some incredibly tight turns with short lengths.?ÿ His goal is to keep vertical data consistently within 0.001 feet for all of the various piping elevations.?ÿ What is the best category of level to use inside with relatively slick concrete floors and continuous vibration and noise??ÿ What is the best way to carry an elevation up about 25 feet from what is supposed to be a very solid bench mark to hit a spot on a landing where a set up can be made to start working inside the three story building.?ÿ Multiple attempts using standard total station set ups and prisms has varied 0.003 and more.

Kinematics.com. Thats the software spatial analyzer. ?ÿThey do great training on multiple different types of equipment. Leica faro api all have good laser trackers. I would highly recommend before purchasing contacting the folks in williamsburg va on spatial analyzer. ?ÿPay the money for them to come and evaluate the site and make recommendations on the instrument types needed. ?ÿPicture a .22 led bullet that has hit a wall and you dig it out. I have used the faro arms to map that and create a surface a ten triangles and model it and position where it went into that wall and from where with the laser tracker. Boats airplanes ships all mapped and built with these things. ?ÿI hope this helps. ?ÿI even had a great tire manufacturer in a week class i went to as they were looking at changing the way the built tires so they would be more accurate and precise. ?ÿSo these tools were monitoring the pullies and such in real time. ?ÿ

I recommend Freiberger FG005 Automatic Level, got some excellently precise results on similar projects, eg. glass factory datums?ÿ

Another option would be a decent Automatic level with a Parallel Plate Micrometer, eg. Leica NAK3 with GPM3 Micrometer

To get up the 24 ft pull steel band to tension, on a column or similar.?ÿ

Sounds like a fun project for a friend.

@olemanriver?ÿ

40 thousandths of an inch is more than 3 thousandths of a foot which is worse than he's doing with the total station.

I've not only been involved with a couple of water plants, in my younger years I worked as a pipe fitter for coded vessel projects. He can let the .001' tolerance go, it ain't gonna happen.?ÿ

?ÿ

Posted by: @mightymoe

I've not only been involved with a couple of water plants, in my younger years I worked as a pipe fitter for coded vessel projects. He can let the .001' tolerance go, it ain't gonna happen.?ÿ

?ÿ

It was a paper mill and not a water treatment plant but I was asked to place a benchmark for the boilermakers.?ÿ The equipment I had was a Dumpy level and a Philadelphia rod (40+ years ago).?ÿ I set it on an anchor bolt, wrote the elevation (to the hundredth of a foot) on the column, tied back in flat, and left the area.?ÿ I got a call from the boilermaker superintendent saying he needed the elevation to the thousandth of a foot.?ÿ I came back and added a zero to the end of the elevation and left.?ÿ To the best of my knowledge they're still making paper at that plant.

Andy

@mathteacher inch 40 thousanths of an inch .0001 meters.1mm.?ÿ

@mathteacher sorry math for marines lol. He can get down to .1mm with correct laser tracker and smr smr is a prism for our knowledge or verbiage. ?ÿNGS has uses them for certain uses. ?ÿThey are very neat and in small areas no way i have seen to get better and be more productive. ?ÿThe one i had was good to about 90 meters distance before losing accuracy. That was with a calibrated smr or prism. ?ÿMetrology measurements. Shoot more points a minute than we can in 30 minutes. ?ÿI alligned a pipe that was 50 ft long. Shot the diameter every 1mm and length wise 1 mm. All over. ?ÿCrazy tool. Its like a robot on crack

@mathteacher I was misplacing the decimal in my head. Moving from mm to inches. My bad. ?ÿTruth is the laser tracker will still get him better results. Just need to re think things and dont hire a dyslexic old jar head to run numbers in is head. ?ÿI also didnƒ??t like working with inches for the mechanical engineers I was dealing with. The other benefit of laser tracker is he can set monitor targets up throughout the building and as the tracjer can be placed anywhere or multiple laser trackers and relative tie to any monitor points and calculate drift settlement in real time. ?ÿAnd have a 3d position better than what he is looking for in just vertical. I enjoyed doing stuff at that level I really learned a lot. But i also hope I never have to do it again. ?ÿTo tedious. But I would if tasked with his job build the 3d system in the plant and be done. ?ÿI think ngs uses one in conjunction with triangulation and other methods when positioning the VLBI sensors and other sensors for itrf datum etc. ?ÿ they just had to adjust for ellipsoid etc. ?ÿall the other sensors and measurements that take place besides what we as surveyors use to create datums. ?ÿSorry for the wrong decimal place. ?ÿ

@olemanriver?ÿ

I checked it three different ways. At age 76, I try not to shoot from the hip, 'cause I'm not always sure where my hip is.

Posted by: @mathteacher

@olemanriver?ÿ

'cause I'm not always sure where my hip is.

Isn't that where it hurts when you walk? Or maybe you can't pick that out of all the other hurts.

Posted by: @nate-the-surveyor

Just loosen up those tolerances....

Bam! Solved!

Generally, the engineer hires an out of town surveyor that will tell them they can hit the tolerance, and then no questions are asked.

Posted by: @mathteacher

@olemanriver?ÿ

40 thousandths of an inch is more than 3 thousandths of a foot which is worse than he's doing with the total station.

I think it is about the same??ÿ (1/12)*.040=0.00333

Posted by: @mathteacher

@olemanriver?ÿ

I checked it three different ways. At age 76, I try not to shoot from the hip, 'cause I'm not always sure where my hip is.

I should stop shooting from the hip myself. I am glad you caught me putting my foot in my mouth. I was out staking curb and gutter I just hope they donƒ??t find that stake I was figuring on and it was cold for me to brake out my hillbilly calculator today with ice still on the ground. ?ÿBut the mississippi never leaves the boy. ????. ?ÿRunning levels in tight spots is challenging. Especially at short distance. ?ÿI ran three wires through a va hospital once back in The 90ƒ??s . We had god overall closure but the error showed up when running the other loops within the building. Lots of head scratching. ?ÿNone of the tolerances were as tight as what this job needs. I still say laser tracker is a no brainer. ?ÿ5 years ago I would have not even mentioned one or did I know what one was. ?ÿAfter using one for a few years and wrapping my brain around understanding the terminology which can be confusing for a surveyor at first. Because the verbiage is identical to some we use but not exactly the same. Once the light bulb ???­ came on I was amazed at what I could achieve. In the right environment only though. ?ÿ

@dmyhill?ÿ

Indeed, @holy-cow and @olemanriver each gave only one significant digit, so comparing beyond that accuracy is improper.

Edit: Actually, @olemanriver gave two significant digts; the trailing zero is significant. But comparing 0.003 to 0.0033 is not proper.