Construction And Mode Of Operation; Transducer; Sg Cover - HBM C9B Montageanleitung

C9B
3

Construction and mode of operation

3.1 Transducer

The measuring body is a membrane that is mounted on four strain gages
(SG) so that two are stretched and two compressed. Force is applied to the
measuring body of the C9B via a ball‐shaped load button (see also Page 13).
The membrane with the SG is elastically deformed by the force acting in the
measuring direction. The strain gauge changes its ohmic resistance in propor­
tion to its change in length and so unbalances the Wheatstone bridge. If there
is a bridge excitation voltage, the circuit produces an output signal propor­
tional to the change in resistance and thus also proportional to the applied
force.

3.2 SG cover

To protect the SG, the C9B force transducers are welded on the base, and on
the top with some types, with a thin metal plate cover (Fig 3.1). This proce­
dure offers the SG a high protection against environmental influences.
Fig 3.1: SG protection
NOTE
The relatively thin housing cover (specially within the measuring range up to
200 N) and base (all measuring ranges) of the transducer must not be
stressed. The specifications list the permissible limits for mechanical, thermal
and electrical stress. They must be complied with, otherwise the transducer
can be destroyed.
A2088-3.0 en/de/fr
9
HBM