An optical level consists of
a scope with a crosshair, through which the levelling staff is targeted. It has
a spirit level to aid in making the instrument level during setup and it is
mounted on a tripod with adjustable legs.
Some optical levels are
digital and can automatically take a reading from an appropriate levelling
To take measurements with an
optical level you must:
- Set up a tripod so the legs are equally spaced and the
top roughly horizontal.
- Remove the optical level from the hard case and screw it onto
- Once secure, level the apparatus with the spirit level
and the levelling screws on the optical level. Now, any point to which the
crosshair aims at will be on the same horizontal plane.
- Readings can be taken once the set up is complete. To do
this look through the eyepiece and use the focus knob to clearly examine the
- When readings have been taken from all points in range, the optical
level must be moved to another position and re-levelled and calibrated. A back
sight must be taken once the optical level is in its new position.