|
The soil strainmeter employs a potentiometer and a rod
mounted between two anchors to monitor horizontal movements of the
surrounding soil. These components are linked together so that movement of
one anchor relative to the other causes a change in the output of the
potentiometer. The initial reading of the strainmeter is used as a datum.
Subsequent readings are compared to the datum to calculate the magnitude,
rate, and acceleration of movement.
Strainmeters are usually installed in series along the
axis of anticipated deformation. Strainmeters may also be arranged in arrays
or in groups with different alignments. A gauge length of 3 to 6 meters is
typical, but will vary according to the expected magnitude of movement and
the type of structure being monitored.
The strainmeter is available in two versions. The
double-sensor version is equipped with two potentiometers mounted
back-to-back to provide cable savings. The single-sensor version is used
with odd number series or when only one gauge length is required.
|
