
174
27.EXPLANATIONS
Sighting can be more accurately performed by facing the 360° Prism toward the instrument. The 360°
Prism should be set up so that a pair of diametrically-opposed hexagonal points on its rubber flanges
are aligned with the sighting direction of the instrument (see the diagram below).
When using the ATP1S, the 360° Prism should be set up so that a pair of diametrically-opposed marks
on top of the prism are aligned with the sighting direction of the instrument.
27.1
High Accuracy with the 360° Prism
: Hexagonal points
: Prism sighting direction