Page 73 - Lehrbuch Neigungsmessung deutsch 2018.indd

COMPENDIUM INCLINATION MEASUREMENT
WYLER AG, WINTERTHUR / SWITZERLAND

• Two virtual flat parallel surfaces making contact with the measured grid surface at the highest and
the lowest points are turned freely in space until the distance between the two virtual surfaces is the
minimum. This distance is the FLATNESS ERROR ACCORDING TO ISO 1101

Minimum distance is
maximum error of the surface
(Flatness error)

Remarks:
Both parallel virtual surfaces make contact with the measured grid on four points. Three options are pos-
sible:
• Option 1:
Three contact points on top and one on the bottom (The one single point must lay within the
triangular area created by the three other points)
• Option 2:
Three contact points on the bottom and one on top (The one single point must lay within the
triangular area created by the three other points)
• Option 3:
Two contact points on top and two contact points on the bottom (Connecting line between the
two top contact points and connecting line between the two bottom contact points must virtually
cross each other)
Only when one of these three requirements is fulfilled has the alignment been correctly performed accor-
ding to ISO 1101.

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