Mounted on shaft 1 subject to
torsion are two bushings which
carry capacitor plates 2 and 3,
arranged parallel to the axis of
the shaft. One of the plates is
insulated from the shaft and
is positioned w ith a certain air
gap parallel to the other plate.
When the shaft is twisted in
torsion, the distance between
plates 2 and 3 is changed. This
changes the capacitance of the
capacitor they form. The change
in capacitance is recorded by
a suitable measuring instrument.