Ok, I must admit it, I learned something today and thought I’d share. A fairly inexpensive method to level a floor and definitely not what I expected. But it does make sense provided both individuals use the meniscus as the base of measurement. Heck, over the distance measured, a millimeter or 2 would not matter that much.
They started with measurement at center of floor space and transferred to columns. Not bad, not bad at all.
Refer to the plastic tubing containing water in attached photo. Meets the purpose of my 5-point auto-leveling laser.
I have seen that method used to install drop ceilings.
And on a related note;
When I was about 15, my Dad built a rail fence in the yard.
He challenged me to find what he had used to level the rails.
I was baffled until he hinted that he had had to look a long way to find his level.
Then I figured it out.
We were on the shore of a lake that was 2 or 3 miles wide.
Dad had lined up the rails with the opposite lake shore.
I levelled the deck on our old house, prior to sale, using the U-tube manometer principle. Trickiest part is making sure you don’t have a trapped bubble somewhere, and that you can move the bubble out of the tube if one does develop. First go with 1/16" spaghetti tube was a failure for that reason, had better luck with some 3/8" vinyl tubing.