| This meter is used to measure very slight relative
displacements between two points and is mainly used for quick
and accurate measurement of tunnel convergence.
Measuring may be done in any direction. Besides tunnels, the
meter may be used for measuring displacement of vertical shafts,
deformation of mine supports, landslides, deformation of soil
retaining walls, or displacement of abutments, bridge piers
and bridge slabs.
Two types of measurement points are available, the grip-anchor-type,
which is embedded in shotcrete or secondary lining concrete,
and the steel bar type, which is installed by thrusting it into