Dave:

I'll echo Eric's comments about the use of a laser level for minimal level
work.

Definitely don't try to use it for the whole site or layout as the error
factor is going to be too great, and, of course, the bigger the site (and
you always need to relate your site to the rest of the world) the bigger
the error, which these things cannot handle.

Use a precision instrument to lay out your primary grid and get elevations,
but have little fear doing the lighter horizontal and unit work using one
of the popular building / contractor / do-it-yourselfer laser levels (look
like a foot long bubble level with a laser light) that you can now find for
a couple dozen bucks at any hardware store.

One way to make life easy is to set up several semipermanent platforms,
perhaps just a cement block or similar) for which you know the value
(preferably all equal elevations).  By placing three or four of these
platforms around the perimeter of the site you can do quick shots anywhere
you need within the site (always try to measure your site from outside
inwards as it lessens the error).  Then it is a matter of just turning the
thing on and aiming it where you want it for as long as you need it.  You
might find it takes two people, but there are tricks around this if you are
clever.

If you have a big crew and complicated site get a couple of these lasers
donated!

Personally, I am waiting for the nice rotating contractor's lasers to be a
bit more affordable.  They just sit in the middle of the site on a tripod
and do great over a hundred or more feet.  Since it spins the beam in a
circle you don't need to turn it your way when you move to a different
spot.  Just set it up, turn it on, figure the instrument height, and go
about your work.

No matter what, you still have to know what you are doing as a surveyor -
none of these instruments can do the work for you, they are just a
different-fangled tool.

         Dan W.




>Dave
>         We have been using a laser level at Jamestown over the last
> season with
>great results. We still shoot all our elevations with a total station but
>the laser level has been a very successful replacement for the string and
>line level for drawing sections. The laser never sags and can hold a level
>for long sections, 50 feet plus. For the money they can't be beat.
>
>
>``                                      Eric Deetz
>
>Senior Archaeologist
>
>APVA Jamestown Rediscovery