On Sun, 31 Dec 2017 13:27:59 -0600, -MIKE-
wrote:

On 12/31/17 1:13 PM, Emanuel Berg wrote:
Bill wrote:

As I indicated in my post, a 100% accurate
level would be a PITA.

100% literally would be impossible but
100% practically speaking - why would that be
a PITA? Because nothing would ever satisfy it?

Well, if so, a ruler for example - I always
considered that 100% accurate practically
speaking but that hasn't stopped anyone from
using it as far as I know?


The point he's making is that close enough is close enough for most uses
of a 2 or 4ft level.
If you need more accurate, you go to a 6 or 8ft level.

A 6 or 8 foot level is not necessarily more accurate than a 24 inch
level - and in fact there are 4 inch or 6 inch levels that are MORE
accurate than the runof the mill 4 or 6 foot level
I have a few 4ft levels and more, for whatever reason, is much more
accurate than the others. In many situations, I don't use it because it
is a bit of a PITA.
I don't need to be scootching an 8ft wall back and forth to try to
achieve plumb to within 1/64". That's what happens with this particular
level. The center of the spirit vials is much flatter requiring much
more precision in movement to get the bubble dead-center. Whereas, the
other two have a much more pronounced curve to the viral meaning the
precision of movement needed to get the bubble dead center is much more
forgiving.


You figured it out!!! It's not the length of the level that makes it
more accurate, it's the radius of the vial.
When that level is dead center, it might be accurate 1/16" in 8ft, which
is plenty enough for framing.

It's like using the course adjustment instead of the fine adjustment.
Just like with a framing square. It needs to measure decent framing
angles, not send a space probe to mars.


Or close a survey within 1/10 of an inch over 2000 feet.