EL In-Place Inclinometer, 2008/7/09 1
Introduction
In-Place
Inclinometers
The in-place inclinometer system consists of
inclinometer casing and a string of linked
in-place inclinometer sensors.
The inclinometer casing provides access for sub-
surface measurements, controls the orientation of
the sensors, and moves with the surrounding
ground.
In vertical installations, the inclinometer casing is
installed in a borehole that passes through a sus-
pected zone of movement. One set of grooves is
aligned in the expected direction of movement
(downhill, for example).
In horizontal installations, inclinometer casing is
typically installed in a trench. One set of grooves
must be aligned to vertical, since the instrument is
expected to monitor vertical movements (settle-
ment or heave).
The string of linked sensors is positioned inside
the casing to span the zone of movement. When
the ground moves, the casing moves with it,
changing the inclination of the sensors inside the
casing.
Sensors for vertical installations measure inclination from vertical. Sen-
sors for horizontal installations measure inclination from horizontal.
Inclination measurements from the sensors are processed to provide
displacement readings in mm of displacement for the gauge length of
each sensor.
In most applications, sensors are connected to a data acquisition system
and data processing is completed by a computer program.
Casing
controls
orientation
of sensors
Fixed wheel
points at
direction of
movement
in vertical
installations
Sensor
gauge
length
Inclinometer casing controls the orientation of the sensor
Sensor gauge length
Fixed wheel points down
in horizontal installations
ExpectedDirection
ofMovement
In vertical installations, one
pair of casing grooves should
be aligned with the expected
direction of movement.
In horizontal installations, one
pair of casing grooves must be
aligned to vertical.
Vertical
