Spectron has developed a dual axis tilt sensor
platform, which is comprised of a cylindrical glass
envelope, and five (5) pins which act as the common,
positive and negative electrodes for both axis’ (see
figure 4).
Tilt Sensor Conditioning
The traditional interface of the tilt sensor into a signal
conditioning circuit is as a voltage divider or
ratiometer. This provides intrinsic advantages such as
the normalizing of minor changes in the excitation voltage
and temperature effects.
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The most popular electrical circuit configuration
is the A.C. Wheatstone bridge. The sensor can
be used as one half the bridge with the full
excitation voltage across the sensor, or as the
lower half of the bridge, with resistors in
series with each half of the sensor. At null
(i.e. zero or level), the sensor will produce a
signal equal to 50% of the total scale factor
(output) setting. With angular movement in
either direction, this ratio will increase or
decrease proportionally. For dual axis operation,
a duplicate signal conditioning circuit is
required for the second axis.
Inclinometers
As previously explained, an inclinometer
combines a tilt sensor with integral signal
conditioning electronics. Normally, mechanical
mounting features of some type are
incorporated, which provide a positive reference
surface. This surface is used to properly align
the inclinometer during installation. Many users
prefer inclinometers to tilt sensors, as it
eliminates the laborious tasks of circuit design,
sensor mounting/alignment and calibration.
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