Users’ Manual
ESM-40S High sensitivity settlement monitoring system
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2 DIGITAL SETTLEMENT MONITORING SYSTEM
2.1 General description
Model ESM-40S high sensitivity liquid level settlement monitoring system consists of:
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Model ESM-40S/1 Settlement sensor
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ESM-40S/2 Reference reservoir with liquid level measuring scale, wall mounting accessories
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ESM-40S/3 Desiccant unit (moisture trap) with wall mounting accessories
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ESM-40S/4 Fluid tube, 8 mm od
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ESM-40S/4 Air vent tube, 8 mm od
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T connector with two (male female) connectors for signal cable
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CS-1002 3-core signal cable
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ESM-40S/5 Pressure gage assembly unit (required with pressure vessel system)
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ESM-40S/6 Pressure vessel and pump (to be arranged locally by user, or procured from Encardio-rite
separately)
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De-aired fluid (to be arranged locally by user, or procured from Encardio-rite separately)
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Model ESDL-30 Datalogger or equivalent
The settlement sensors are also interconnected with an air vent tube that is eventually terminated at
moisture trap with desiccant. The common vent line being open to atmosphere helps the settlement reading
not being affected by local air current and changes in barometric pressure.
2.2 Operating principle
The settlement sensors are mounted at locations where settlement is to be monitored. These are
connected in series by a fluid filled tube and finally to a reference reservoir mounted at a stable location.
Stable location must be away from the zone of influence, where no displacement is expected.
All interconnected settlement sensors are mounted at almost same elevation and have a common fluid
level initially. A reference settlement sensor is installed near the reference reservoir, to compensate any
change in fluid level in the reservoir. It is mounted atleast 50 to 75 mm below the minimum water level
mark on reservoir.
The settlement sensors’ mounting location/elevation depends on amount of settlement or heave expected.
Preferably, in case settlement is expected, the settlement sensors are mounted atleast 100 mm below the
minimum water level mark on the reservoir.
Figure 2-1 Schematic diagram of ESM-40S settlement monitoring system
Fluid tube
Deaired water
reservoir
Settlement
sensor #N
Re
fe
re
nc
e
lev
el he
ad
Lev
el
head
#
2
Lev
el
hea
d #
N
Reference
sensor
Datalogger
ESDL-30
Digital signal cable
Air vent tube
Settlement zone
Fluid reservoir level
Settlement
sensor #2
Settlement
sensor #1
T connector
Bleed screw
Stable zone
Air vent
Dessicant
Hydrophobic Filter
