Piezometer is used to measure underground water pressure. It converts water pressure to a frequency signal via a diaphragm and a tensioned steel wire. A change in pressure on the diaphragm causes a change in tension of the wire.
Inclinometers measure the orientation angle of an object with respect to the force of gravity. This is done by means of an accelerometer, which monitors the effect of gravity on a tiny mass suspended in an elastic support structure.