The central functional part of the sensor is a spring element
in a cross shaped arrangement. The spring element is fixed
to the base of the measuring equipment at one end and free
to turn within a small angle on the other. Such a set-up is
very sensitive to an applied torque causing a torsion of the
element but rather stiff in axial direction allowing relative
large loads to be applied. The torsion angle of the spring
element is directly proportional to the mechanical moment
applied to the sensor element.