Spectra LL300-2, LL300N-3 Leveling Accuracy, Influences on the leveling accuracy, Accuracy Check

In order to avoid offset errors, the receiver should be used close to the elevation where the laser has been set up.

If a remote control is available, the up and down arrow buttons can be used for fine adjustments.

LEVELING ACCURACY

Influences on the leveling accuracy

The overall accuracy of the unit can be influenced by many factors:

•factory accuracy;

•temperature of the unit;

•ambient influences like rain, wind and temperature.

The factor that influences on the unit’s accuracy most is the ambient temperature. Vertical differences in temperature near the ground can divert the laser beam, similar to the heat waves seen on hot asphalt streets.

This factor also applies to all optical measuring devices such as automatic levels and theodolites.

Accuracy Check

To ensure job-site accuracy, you need a distance of 20 m (65 feet) between two walls A and B, where you will execute 4 measuring operations on a tripod as follows (transit measurement).

Set the unit horizontally on a tripod near wall A and switch it on with the plus X-axis pointing towards wall A. After the unit is level, mark the height of the laser beam using a receiver at wall A. Turn the entire unit 180°, let it self-level and mark the center of the laser beam at wall B.

1	20m
A	B
	1.2
1.1

Now, place the unit near wall B with the plus X-axis pointing towards wall B. After the unit is level, mark the height of the laser beam at wall B. Turn the entire unit 180°, let it self-level and mark the center of the laser beam at wall A. The difference (h) of the marked points at wall A shows the deviation.

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