Best practices/literature on field measurements?

[YungPlantEng]

This isn’t applicable to just structures but is there any standards or literature that goes through how to take field measurements at various levels of precision? Let’s say I have an old tank and want to dimension it for design calculations - or I want to get precise measurements for a retrofit on a very old burner with lackluster drawings. Is laser measurement the go to? How is this set up and supported to reduce error?

 

[dik]

I've done a few modifications in mines where the information was done using a small drone with LiDAR and also one northern hydro station. Last one was a long monorail crane with a 25'ish cantilever for hoisting things down the shaft... The AutoCAD file was about 80MB, and I was surprised I could open it with Bricscad, modify it, and it was readily readable with AutoCAD.

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So strange to see the singularity approaching while the entire planet is rapidly turning into a hellscape. -John Coates

-Dik

 

[bugbus]

Agree with dik, lidar is great, especially working in and around existing structures. I was told it can reliably get down to 5-10 mm accuracy even over large survey areas.

We used it to design some new bridges that had to fit right up close to some existing structures, which had originally not been built in a straight line and had all sorts of wonkiness we had to accommodate.

Photogrammetry is also interesting. Even using just a smartphone camera and certain photogrammetry apps, you can create surprisingly accurate 3D models. Newer smartphones have lidar also.

 

[human909]

We use one of these for site measurements.

https://leica-geosystems.com/products/laser-scanners/scanners/leica-rtc360

It is reliable to +/-1mm in my experience. Which is good enough for structural steel modifications on brown field sites. The challenge is more about dealing with the huge amount of information it gathers rather than with its own accuracy.

It doesn't always have enough resolution to accurately determine a member size eg an 10.5mm flange or a 12mm flange. For anything critical I insist on site measurement and generally visit the site itself.