How to set 90 degree SQUARING with a Rotary Laser Level
The following description in this guide, explains the general principles of setting-out
90 degree squaring when using a rotary laser level. It speeds up the classic 3x4x5
triangle method, giving better accuracy and alignment over much longer distances.
This information is intended to be read in conjunction with your laser level’s
Instruction Manual.
Equipment:
You need a rotary laser level which is designed to set “squaring”. It will have an extra
dot beam out of the top of the rotating prism & can be either a red or green beam
laser.
In addition, you will require a matching laser detector (receiver), a target plate and
preferably a remote control. You do not need a tripod nor staff.
(Without a remote control; having another person to assist you, is useful.)
Site Conditions:
There are many different worksite scenarios. As an example, we are assuming that
you have laid a concrete pad or completed your strip foundations (footings) and are
ready to set out in one corner, 90 degree (squaring) for brickwork, blocks or timber
framing, over a datum *mark*.
Procedure:
Place the laser in “
lay-down
” over your corner datum *mark*, on the concrete surface
& switch ON. Wait for it to auto (self) level, then change to MANUAL. As this
procedure is using “alignment” rather than “levelling” it is more convenient to use the
laser in its Manual mode. See your laser’s User Instructions - if necessary.
Next, remove the bracket from your laser detector. Switch the detector ON and lay it
on its SIDE over a distant mark along one side of the concrete slab or strip footing.
The pick-up window must be facing the rotating beam of the laser level. Using the
remote control, direct the spinning beam to receive a continuous audible tone on the
detector. This has aligned the laser beam exactly on the distant mark.
Next, observe the laser dot projecting from the rotating prism. This is now parallel
with the concrete slab or footings along the other axis. Laser prisms are optically cut
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