"Alex" wrote in message
om...
I have recently bought a laser level but it doesn't come with a
manual.

I'm having a few troubles sometimes calibrating the thing as there are
three water levels to be set: one for the tripod, another for the base
and the third for the level itself.
The level on the base is particularly tricky because the base itself
has to be rotated (useful feature for many jobs).
Has anyone found a trusted and quick way of calibrating optical
instruments using three adjustable screws?

Any hint would be appreciated.

Standard technique as for levelling a surveyor's theodolite. (They tend to
have straight vials, rather than bulls-eye bubbles.)

Assuming you've got the same kit as me!
Stand opposite the "0" degree mark.
Choose the two screws close to you (at the 60 & 300 deg. marks). You now
level in a sideways mode using these two screws together but turning equally
in opposite directions until the bubble is centred side to side; and then
using the third screw on the far side (180 deg) you bring the bubble into
the centre of the circle. Check by rotating the head through 180 deg
adjusting if necessary, and then by carefully rotating the head and watching
what happens to the bubble. If there are errors, try to take out just half
the error, rotate and take out half the error; etc.......
--
M Stewart
Milton Keynes, UK
http://www.megalith.freeserve.co.uk/oddimage.htm