The maximum permitted deviation dmax can be calculated as follows:
dmax = double the distance between the walls x 0.0118 in (0.3 mm)
Example: If the distance between the walls is 16 ft (5 m), the maxi-
mum deviation is dmax = 2 x 16 ft x 0.0118 in = 0.118 in (2 x 5m x
0.3 mm/m = 3mm). The marks must therefore be maximum 0.118 in
(3 mm) apart.
Checking the Levelling Accuracy of the Horizontal Line
For the check, an open area of approx. 16 x 16 ft is required.
– Set up the measuring tool on a firm, level surface between both
walls A and B. Allow the measuring tool to level in while in horizontal
operation.
– At a distance of 8 ft (2.5 m) from the measuring tool, mark the center
of the laser line (point I on wall A and point II on wall B) on both walls.
A
B
– Set up the measuring tool 16 ft (5 m) away turned by 180° and allow
it to level in.
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