HBK 10M0, Mounting Instructions, Page: 12 / 106

C5
STRUCTURE AND MODE OF OPERATION
10
5 STRUCTURE AND MODE OF OPERATION
5.1 Force transducer operation
The measuring body is a steel spring element to which strain gages are applied. The
strain gages for each measuring circuit are installed so that four extend and four shorten
when a force acts on the transducer. Each strain gage changes its ohmic resistance in
proportion to its change in length and so misaligns the Wheatstone bridge. If bridge
excitation voltage is present, the circuit produces an output signal proportional to the
change in resistance and therefore also proportional to the applied force. The SGs are
arranged such that parasitic forces or torques and temperature effects are compensated
as much as possible.
If the bending moment bridges option is selected, the force transducer is equipped with
two additional measuring bridges. These measuring bridges are installed in such a way
that force acting in the measuring direction is largely compensated, but acting bending
moments (such as due to eccentric force action) lead to an output signal.
5.2 Strain gage housing
To protect the strain gages, the column-type force transducers have a housing which is
screwed to the force transducer and protects the strain gages from external influences.
The housing must not be removed or damaged.