Structure And Mode Of Operation; Transducer; Sg Covering Agent - HBM C9C Mounting Instructions

Structure and mode of operation

4 Structure and mode of operation
12
4.1

Transducer

The measuring body is a steel loaded member on which
strain gauges (SG) are installed. The influence of a force
deforms the measuring body, so there is deformation in
places where the strain gauges are installed. The SG are
attached so that two are stretched and two are
compressed when a force is applied. The strain gauges
are wired to form a Wheatstone bridge circuit. They
change their ohmic resistance in proportion to their
change in length and so unbalance the Wheatstone
bridge. If there is an excitation voltage, the circuit
produces an output signal proportional to the change in
resistance and thus also proportional to the applied force.
The strain gauge arrangement is chosen to compensate,
as much as possible, for parasitic forces and moments
(e.g. lateral forces and eccentricity influences), as well as
the effects of temperature.
4.2

SG covering agent

To protect the SG, the force transducers have thin cover
plates that are welded on the bottom and, in versions
with a nominal (rated) force of up to 200 N, on the top.
This method offers very good protection against
environmental influences so that the C9C achieves
protection class IP67. In order to retain the protective
effect, these plates must not be removed or damaged in
any way.
A3729-2.2 HBM: public
C9C