While most people are sleeping or partying way too late this holiday weekend, we will be breaking out the big "Orange box of Plumb".
The ZNL is used to "quick center" and is only rated at 1 in 30,000 (one sigma) with two observations at 180 degrees. It will get us into about 1mm at 30 m or 0.003 feet at 100 feet.
Merely a quick setup device to get us above and below center.
The ZL and NL are rated at +/- 1 in 200,000 (one sigma) with two observations at 180 degrees and will provide the real observations. Having each will allow us to do the job reciprocally from below and above. They will provide an accuracy of +/- 0.5 mm at 100m or +/- 0.0015 feet at 300 feet each.
Considering our aim is to plumb some 426 meters reciprocally over several nights, our error propogation should be pretty manageable.
I would be tempted to leave it setup until daylight and watch the building move as the sun hits one side.
James
> I would be tempted to leave it setup until daylight and watch the building move as the sun hits one side.
>
> James
Me Too!!!
B-)
GSCHROCK,
Could you send me an email= smithgps AT myfairpoint DOT net
Bob in NH