With coordinate metrology, the relative accuracy to the range of measurement is more practical than the nominal one. E.g., a measurement accuracy of 1 nm is too low for 10 nm pattern of semiconductor circuit. In contrast, a measurement accuracy of 1 mm is too high for 1 km long bridge.
The range of relative measurement accuracy for industrial applications:
1. The lower bound: 1/100, i.e. 1 cm for 1 m
2. Usual requirement: 1/1,000 ~ 1/100,000
2. The upper bound: 1/1,000,000, i.e. 1 mm for 1 km.
There are a variety of measurement methods and tools available for industrial applications.
For moon observation, a telescope.
For cell investigation, a microscope.
Joon
1mm accuracy
- Dave Andrews
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Re: 1mm accuracy
Haha yeah it’s a touch pricey. Our tracker rate is 4 times the survey rate.landmeterbeuckx wrote: ↑Sat Mar 07, 2020 5:07 amwow, you got to have some decent jobs for this gear to earn it back. I suppose the rates aren't as conventional surveying?Dave Andrews wrote: ↑Fri Mar 06, 2020 5:51 pmWe have a little over $140k in 1 tracker and everything to do what we need. Now, we also do high precision alignment so the tooling needs a huge expense.landmeterbeuckx wrote: ↑Fri Mar 06, 2020 3:05 pm
What price range are these trackers actually? I knwo Leica and Faro have them but have never used or seen one irl.
"The harder you work, the harder it is to surrender."
Woody Hayes
Woody Hayes
- stevenramsey
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Re: 1mm accuracy
Usual question has anyone bothered asking the client what they are using the data for and helping them understand what level of Accuracy/precision they really actually need
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Re: 1mm accuracy
Yes, we've asked the client - they are looking at a subsidence issue. The trouble is that when a client reads something like the article below, why wouldn't they want the best possible accuracy?
https://www.spar3d.com/news/lidar/faro- ... -accuracy/
We get over-specced tenders all the time! Clients asking for 2mm point spacing on a building facade and then when you deliver, they cannot work with the point cloud and so we have to reduce it.
https://www.spar3d.com/news/lidar/faro- ... -accuracy/
We get over-specced tenders all the time! Clients asking for 2mm point spacing on a building facade and then when you deliver, they cannot work with the point cloud and so we have to reduce it.
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Re: 1mm accuracy
That's a shame I wish you luck in educating your client...if you can.
There is a saying that I have heard that is a good representation of this ignorance problem.
"Measure it with a micrometer, mark it with caulk, cut it with a chainsaw."
How is the contractor going to ensure they hit that mark even if you can? This is why I also suggested supplying tracker services during construction.
Edit: Sounds like the project is still over-specified, but at least you might get a chance to use a tracker, and possibly charge 4x what you would normally due to their ignorance. I think that it would be better to educate them and get the specified accuracy reduced, but in the event that fails you will still be giving them excellent data.
There is a saying that I have heard that is a good representation of this ignorance problem.
"Measure it with a micrometer, mark it with caulk, cut it with a chainsaw."
How is the contractor going to ensure they hit that mark even if you can? This is why I also suggested supplying tracker services during construction.
Edit: Sounds like the project is still over-specified, but at least you might get a chance to use a tracker, and possibly charge 4x what you would normally due to their ignorance. I think that it would be better to educate them and get the specified accuracy reduced, but in the event that fails you will still be giving them excellent data.
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