Mine Surveying Applications
This page contains useful information about Wall Stations. Select a topic from the list below to read more.
The Leica prism system is a critical component to wall stations. Leica have designed this prism to be physically centered on a true axis. Other prism makers that use the industry standard 30mm or 0mm offset type prism in fact are not centered on axis in all 3 directions. The Leica prism is designed to allow the prism to point in any direction and at any orientation and still allow the Surveyor the ability to sight the reference point of the prism.
Target plates are of no use when using wall stations as the prism is rarely placed in a horizontal or vertical orientation. Target plates are only useful if the prism is utilised with a carrier and tribrach.
The Leica GPR1 prism can be easily separated from the GPH1 holder by rotating the locking mechanism on the back of the prism 90 degrees. The prism should pull away from the holder. This is useful as the prism is robust and does not wear out whereas the holder can wear out at several locations, including where it connects onto the wall stem, the locking button, and the spring washers that creates friction and allows the prism to rotate.
The below images show Leica GPR1 prism with GPH1 holder (front and side view) attached to the wall stem.