Audi A4 2001 Owner's Manual page 64

Electrical system
Functional mechanism of inclination sender
Towing protection is achieved by means of
the inclination sender installed in the central
convenience electronics.
The functional mechanism of the inclination
sender is based on the determination of
resistance changes relating to the volumetric
fluctuation of a viscous electrically conduc-
tive fluid.
The resistance is stored at the moment of
activation of the anti-theft alarm.
Changes in the position of the inclination
sensor caused by one-sided lifting of the
vehicle alter the resistance. The alarm is trig-
gered.
The angle of inclination can be displayed in
the measured value blocks.
64
Variously arranged electrodes project into
this fluid.
Alternating fields are applied to the elec-
trodes of the sender, which is divided into
sub-compartments.
When a change in position occurs, the distri-
bution of the fluid in the chambers also
changes.
As the level of the liquid in the sub-compart-
ments changes, the resistance determined for
the sub-compartments via the electrodes also
changes.
Ceramic
housing
Indicator
fluid
Electrodes
Electrode
connections
SSP254_110
Sub-com-
partment
Operational
amplifier
SSP254_111