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DESIGN AND MODE OF OPERATION
5.1
Transducer
The measuring body is a loaded member made of steel (for nominal (rated) forces from
12.5 kN) or high-strength aluminum (for nominal (rated) forces up to 5 kN) to which strain
gages (SG) 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 tempera
ture effects are compensated as much as possible.
5.2
Strain gage housing
To protect the SG, the force transducers have thin cover plates that are welded (steel ver
sions) or glued (aluminum versions) top and bottom. This method provides the strain
gages with a high degree of protection against environmental influences. In order to
retain their protective effect, these plates must not be damaged in any way.
5.3
Permanently connected amplifier module option
The sensors can optionally be ordered with an inline amplifier. This amplifier module sup
plies the bridge circuit of the sensors with a suitable supply voltage, and converts the low
output signal of the force transducers into analog current or voltage signals. A digital
interface is also available (IO-LINK). See section 8.2, page 30.
U10M
DESIGN AND MODE OF OPERATION
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