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COMPENDIUM INCLINATION MEASUREMENT
WYLER AG, WINTERTHUR / SWITZERLAND

1.8 CORRELATION BETWEEN THE MOST COMMON UNITS IN INCLINATION MEASUREMENT

1 Rad corresponds to 57.30°
1 mRad corresponds to 206.26 Arcsec
1 degree corresponds to approx. 17.45 mm/m or 17.45 mRad
1 Arcsec corresponds to approx. 4.85 μm/m
1.9 WHAT ARE POSITIVE AND NEGATIVE INCLINATIONS?

WYLER definition:
An inclination is positive when the instrument,
on that side on which an electrical connector is
installed, is lifted. When the instrument under the
same precondition is declined, we define this as a
negative inclination.

1.10 THE ABSOLUTE ZERO BY MEANS OF A REVERSAL MEASUREMENT
Using the reversal measurement is a simple way
to determine the exact ZERO-OFFSET of the instru-
ment as well as the exact inclination of the surface
the instrument is placed on.
The absolute zero represents a base for absolute Reversal
inclination measurements (deviation from horizontal measurement
or vertical). In order to achieve best results, take care
that the measuring instrument and measuring object are at identical temperatures and put the measuring
instrument into operation a few minutes prior to zero setting. The absolute zero is automatically calculated
and set from the two values entered while conducting a reversal measurement (reversal measurement =
two measurements made on the same spot, but in exactly opposing directions). For this operation, place
the measuring instrument upon a suitable surface, (rigid location; as flat as possible; as near to horizontal
as possible). In order to allow positioning in exactly the same location after rotating the instrument through
180 degrees, mark out position and particularly the orientation of the measuring instrument.
The determination of the absolute zero of the instrument is essential when an absolute measurement
is performed. Before the actual measurement with the measuring instruments, a reversal measurement
has to be performed. The determined deviation of the zero point (ZERO-OFFSET) of the instrument is con-
sidered in the display readings. For measuring instruments of earlier generations, the ZERO-OFFSET has
to be corrected manually. For spirit levels the zero-point deviation has to be adjusted by means of the vial.
Normally, the reversal measurement is part of the application software used.
The results of a reversal measurement are:
• ZERO-POINT DEVIATION OF INSTRUMENT (ZERO - OFFSET) of the inclination measuring
instrument
• the exact INCLINATION of the surface of the object on which the reversal measurement was
carried out
ZERO-POINT DEVIATION INCLINATION
of the measuring instrument (ZERO-OFFSET) of the surface of the object
(X + X‘) (X - X‘)
= =
2 2
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