Geosense HPS-3500 (Hanging)  and IPS-3000 (Inverted) Pendulums are used to measure the tilt or rotation by measuring the relative internal horizontal displacement of points along a true vertical line.  Each has a tensioned, stainless steel wire and the effects of the earth gravitational forces to guarantee a perfectly vertical line between a fixed point and a tensioning mechanism. Typical applications include concrete dams, bridges and high rise buildings.

The HPS-3500 Hanging Pendulum has a fixed point high up in the structure and a heavy weight is used to generate the tension. The weight is submersed in a fluid to damp movements that may be caused by currents of air up through the pendulum shaft.

The IPS-3000 Inverted Pendulum has a fixed point at, or below, the base of the structure and employs a large float in a water filled tank, to generate the tension in the wire.

Measurement of the position of the vertical wire, relative to the structure allows rotation or tilt to be calculated.

Displacements relative to the wire are measured using a manual readout or, for remote reading, the TP-2000 automatic readout is used.