On Apr 19, 11:48 am, art wrote:

As yet I have not found the tolerance range for a spirit level whether
it be angular or otherwise.


If you would simply follow the link that I provided earlier, you could
read:

"The 6" through 18" (150-450 mm) main level vials have graduations
that are approximately 80-90 seconds or .005" per foot (0.42 mm per
meter). There are five, six, or seven lines on each side of the
bubble, depending on the base length.


As for insults to ones intelligence I get
them all the time from idiots who do not have the knoweledge to even
understand the subject let alone give proof of errors stated that they
are trying to challenge.

Perhaps it is because you write with such a lack of clarity that no
one can figure out what your points are.


Look around you Jimmy, here we are in the company of antenna experts,
lots of them. Simple questions are posed by newbies and each expert
writes something different such that an answer is never arrived at.

In the case at hand, several people offered different methods of
work. That you fail to agree with them does not make them invalid;
actually now that I think about it, I think the converse is true.

There is not one expert here that can give a single response that can
satisfy all posters ...

Well, as long as you're one who needs to be satisfied, that will never
happen.

Rest of bafflegab snipped as a service to the readership.

Wes N7WS

Wes wrote in news:1177032145.364625.286810
@d57g2000hsg.googlegroups.com:

"The 6" through 18" (150-450 mm) main level vials have graduations
that are approximately 80-90 seconds or .005" per foot (0.42 mm per
meter). There are five, six, or seven lines on each side of the
bubble, depending on the base length.

Wes, I agree, that is entirely practical. As far as bubble technology goes,
senstivity easily exceeds that, IIRC the plate bubble sensitivity on
theodolites is commonly around 20" (seconds) per 2mm run. By reversing such
a bubble and splitting the difference, it should be possible to achieve an
error well under 0.1mm/m slope.

Realistically, most bubbles for engineering workshop use would be more
accurate than the drilling process, so they are a quite adequate means of
registering the work.

I have used them with success, but prefer an indicator that I can see
clearly while tightening the vice.

Owen