Geokon 6150F, Инструкция по эксплуатации, Страница: 20 / 32

12 | DATA REDUCTION | GEOKON
and the change in displacement (
ΔD
) is:
ΔD
n
= Σ
n
1
L
n
G
n
ΔR
n
EQUATION 5: Deflection Calculation
Where:
Δ R
1
= Sensor’s(
1
) current reading (R
1
(
1
)) minus the sensor’s (
1
) initial, or Zero,
reading (R
0
(
1
)), or (R
1
(
1
)-R
0
(
1
)).
Δ R
2
= Sensor’s(
2
) current reading (R
1
(
2
)) minus sensor’s (
2
) initial, or Zero,
reading (R
0
(
2
)), or (R
1
(
2
)-R
0
(
2
)).
Repeat for all the other sensors in the string.
Although the system is designed for use in continuous segments with pivots, the
sensors can be installed without interconnecting tubing in standard, round
tubing or pipe using special friction anchors. In those systems, the assumption is
made that the measured deflection occurs over the segment length, the
midpoint of which is at the sensor location, and that
L
is the distance between
adjacent midpoints.
4.3 TEMPERATURE CORRECTION
Although the temperature dependence of the MEMS tilt meter is close to zero,
and usually does not require compensation, it sometimes happens that
temperature effects can cause real changes of tilt; therefore, each sensor is
equipped with a device for reading the sensor temperature. This enables
temperature-induced changes in inclination to be distinguished from inclination
due to other sources. The device provides a digital output proportional to the
temperature.
Normally, temperature corrections are not required. An important point to note
is that sudden changes in temperature will cause both the structure and the
sensor to undergo transitory physical changes, which will show up in the
readings. The sensor temperature should always be recorded, and efforts should
be made to obtain readings when the instrument and structure are at thermal
equilibrium. The best time for this tends to be in the late evening or early
morning hours.
4.4 ENVIRONMENTAL FACTORS
Since the purpose of the inclinometer installation is to monitor site conditions,
factors that may affect these conditions should be observed and recorded.
Seemingly minor effects may have real influence on the behavior of the structure
being monitored and may give an early indication of potential problems. Some
of these factors include, but are not limited to, blasting, rainfall, tidal or reservoir
levels, excavation and fill levels and sequences, traffic, temperature and
barometric changes, changes in personnel, nearby construction activities,
seasonal changes, etc.