A Guide on Geotechnical Instruments Types, & Application

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A Guide on Geotechnical Instruments Types,
Application
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WHAT IS GEOTECHNICAL INSTRUMENTATION?
INTRODUCTION
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WHAT IS GEOTECHNICAL MONITORING?
SCOPE OF GEOTECHNICAL SENSORS IN VARIOUS
MONITORING FIELDS
TABLE OF CONTENT
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WHY GEOTECHNICAL MONITORING IS ESSENTIAL?
TYPES OF GEOTECHNICAL INSTRUMENTS
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ADVANTAGES OF GEOTECHNICAL MONITORING
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INTRODUCTION
As the world is developing rapidly and
transforming into a concrete jungle, the need
for geotechnical instrumentation and monitoring
has increased.
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INTRODUCTION
Geotechnical instruments are the sensors that are
used in the geotechnical field or large civil
engineering projects to monitor the health of the
structures. Geotechnical monitoring is necessary
to keep a regular check on structures like dams,
bridges, tunnels, railway tracks, buildings,
etc. Starting from the surveying of land before
constructing a structure on it till its com-
pletion, geotechnical monitoring plays a vital
role.
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WHAT IS GEOTECHNICAL MONITORING?
Geotechnical monitoring is a branch of
geotechnical engineering that deals with
constant health check-up of the structures.
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WHAT IS GEOTECHNICAL MONITORING?
The civil engineering projects require an
extensive amount of monitoring pre and
post-construction to ensure everyone's
safety. For buildings, structures and bridges
etc., it is recommended that Structural Health
should be continuously monitored to ensure proper
maintenance and safety of man as well as the
material. Encardio-Rite is a 52-year-old
geotechnical monitoring company that provides
indig- enous online monitoring services for
civil engineering structural projects and water
resources with remote access to collected data in
real-time.
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WHY GEOTECHNICAL MONITORING IS ESSENTIAL?
A structure can fail because of numerous reasons
like design error, geological insta- bility,
poor maintenance, deterioration of construction
material, etc. However, a good geotechnical
monitoring programme can prevent such failures by
providing the following information
Geotechnical Monitoring for research Determination
and evaluation of design parameters Testing of
new construction materials and techniques Study
of the laws of behaviour of soil, rock and
man-made materials used in the construction of
such structures.

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WHY GEOTECHNICAL MONITORING IS ESSENTIAL?
Geotechnical Monitoring during construction To
verify the hypothesis and the assumptions of
design To monitor safety during construction To
measure the change in parameters during
construction To ensure that the interface of
construction with adjacent structures and
foundation is sound To certify the performance
of the new construction


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WHY GEOTECHNICAL MONITORING IS ESSENTIAL?
Geotechnical Monitoring after construction is
completed Performance monitoring for safety
during the life of the structure Evaluation of
the effect of the structural operation on
parameters like stress, strain, water, pressure,
inclination, deflection etc. Comparison of
observed data with design assumptions


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ADVANTAGES OF GEOTECHNICAL MONITORING
Design Verification Instruments are used to
verify design assumptions and to check that
performance is as predicted. Instrument data
from the initial phase of a project may reveal
the need (or the opportunity) to modify the
design in later phases.


Construction Control Instruments are used to
monitor the effects of construction. Instrument
data can help the engineer determine how fast
construction can proceed without the risk of
failure.
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ADVANTAGES OF GEOTECHNICAL MONITORING
Safety Instruments can provide early warning of
impending failures, allowing time for safe
evacuation of the area and time to implement
remedial action. Safety of adjacent
structures Safety monitoring requires quick
retrieval, processing and presentation of data so
that decisions can be made promptly.


Legal Protection Instrument data can provide
evidence for a legal defence of designers and
contractors against owners of adjacent properties
if they claim that construction has caused
damage.
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ADVANTAGES OF GEOTECHNICAL MONITORING
Performance Instruments are used to monitor the
in-service performance of a structure. For
example, Monitoring parameters such as leakage,
pore-water pressure, and deformation can provide
an indication of the performance of a
dam. Monitoring loads on tiebacks or rock bolts
and movements within a slope can provide an
indication of the performance of a drainage
system installed in a stabilized slope.



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WHAT IS GEOTECHNICAL INSTRUMENTATION?
Instrumentation plays a key role in safety
monitoring of structures and people, providing
necessary information on its performance and
detect problems at an early stage.
The extent and nature of instrumentation not only
depends on the complexity of the structure but
also on the potential for loss of life and
property nearby.
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WHAT IS GEOTECHNICAL INSTRUMENTATION?
This information is critical for the structure's
owner who is directly responsible for any
consequences of its failure. Geotechnical
instrumentation includes different types of
sensors used for measuring pore pressure,
groundwater level, water flow, lateral movement,
deformation, stress, strain and
temperature. Advances in geotechnical
instrumentation, surveying technologies and data
transmission systems make it possible to monitor
the dams, bridges, railways, metros, buildings,
tunnels, etc. from any remote location,
conveniently and economically. The data logger
and total station automatically collect reading
from the installed sensors and targets, at
selected intervals. An alarm is triggered or SMS
is automatically sent if any of the
pre-determined trigger values are exceeded.
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WHAT IS GEOTECHNICAL INSTRUMENTATION?
Data is transmitted to a remote data management
system, at a central server or cloud, where
large quantities of collected data are processed,
evaluated and pre- sented as meaningful
information. The same becomes accessible to the
concerned authorities, at their desk or mobile
devices through the World Wide Web.
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Dam Monitoring Solutions
Parameters Monitored Water level, Water pressure and seepageLateral ground movement, Deformation, DisplacementStress, Strain, LoadTemperatureTilt, Surface Settlement
Services Offered Cloud-based web data presentations for online as well as manual data Sub-surface and surface monitoring of various parameters Pre and post construction building condition survey Laser Scanning
Geotechnical Instrumentation Range Piezometers, Earth Pressure Cells, Strain Gauges, Inclinometers, Plumb Lines, Extensometers, Crack Meters, Joint Meters, Temperature Meters, Load Cells, Data Loggers, Geodetic Targets, Database Management System
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical Instrumentation Scheme Earth Dam
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical Instrumentation Scheme Concrete Dam
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Tunnel Monitoring Solutions
Parameters Monitored Lateral ground movement, Deformation, Displacement Stress, Strain, Load Temperature, Tilt, Surface Settlement
Areas Monitored Underground tunnels and excavations, Struts in cut and cover constructions, Diaphragm Walls, Pile foundations and sheet piles, Adjoining buildings, structures, pavements etc.
Services Offered Cloud-based web data presentations for online as well as manual data Sub-surface and surface monitoring of various parameters Pre and post construction building condition survey, Laser Scanning
Geotechnical Instrumentation Range Piezometers, Earth Pressure Cells, Strain Gauges, Inclinometers, Plumb Lines, Extensometers, Crack Meters, Joint Meters, Temperature Meters Load Cells, Data Loggers, Geodetic Targets, Database Management System
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical instrumentation scheme NATM Tunnel
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical Instrumentation Scheme TBM Tunnel
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical instrumentation scheme Deep Excavation
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Structural Monitoring Solutions
Parameters Monitored Tilt MonitoringCrack MonitoringSettlement MonitoringLateral Ground MovementTemperature MonitoringPore Pressure Monitoring
Services Offered Safety of high-rise buildings during construction, Safety of buildings and infrastructures during construction activity in vicinity, Safety of old and depleted buildings, Safety of structures subjected to long-term movement or degradation of materialsSafety of monuments and structures of historical importance, Safety of structures in landslide prone areas
Geotechnical Instrumentation Range Piezometers, Earth Pressure Cells, Strain Gauges, Inclinometers, Plumb Lines, Extensometers, Crack Meters, Joint Meters, Temperature Meters, Load Cells, Data Loggers, Geodetic Targets, Database Management System
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical Instrumentation Scheme Structures
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical Instrumentation Scheme Structures
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SCOPE OF GEOTECHNICAL INSTRUMENTS IN VARIOUS
MONITORING FIELDS
Typical Instrumentation Scheme Pile Testing
(Foundation)
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TYPES OF GEOTECHNICAL INSTRUMENTS
Multiple sensors are used in the field of
geotechnical monitoring. Encardio-Rite deals
with a wide range of geotechnical instruments
which include piezometers, extensometers, data
loggers, strain gauges, load cells, pressure
cells etc.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Piezometers or Pore Pressure Meters Pore
pressure measurement is crucial for large civil
engineering projects like high rise buildings,
tunnels, dams, etc.
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TYPES OF GEOTECHNICAL INSTRUMENTS
The pressure experienced by the water accumulated
in the pores of earth materials, concrete
structures or rocks is called pore water
pressure. The pore water pressure is measured by
a piezometer sensor which is also popularly
known as pore pressure meter. Encardio-Rite
deals with different types of piezometers to
according to the applica- tion field.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Piezometers

Model EPP-10/10SP Casagrande Piezometer/Standpipe

Model EPP-10/6 Water Level Indicator
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EPP-30V Vibrating Wire Piezometer

Model EPP-40V Vibrating Slim Wire Piezometer
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EPP-50V Vibrating Wire Push-In Piezometer

Model EPP-60V Vibrating Wire Low-Pressure
Piezometer
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EPU-20G Bourdon Gage Type Uplift Pressure
System
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EPU-20V Vibrating Wire Uplift Pressure
System

Model ESM-11V Seepage Measurement Sensor for Weirs
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TYPES OF GEOTECHNICAL INSTRUMENTS
Inclinometers or Clinometers An inclinometer is
a transducer that measures the magnitude of the
inclination angle or deformation in any
structure. The bent is either depicted in
percentage or degrees concerning gravity.
Inclinometers are used to measure the slope
gradient during activities like tunnelling,
excavation and de-watering. Such activities
affect the ground that supports the structure.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of inclinometers

Model EAN-26M Digital Inclinometer System

Model EAN-51MV, EAN-52MV Vertical In-Place
Inclinometer System
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EAN-53MW Wireless In-place Inclinometer
(IPI) System
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TYPES OF GEOTECHNICAL INSTRUMENTS
Tilt Beam Sensors A tilt sensor is designed to
measure the change in tilt and monitor
inclination/verti- cal rotation in vertical
structures.
Tilt sensor produces an electrical signal which
is proportional to the degree of tilt in
multiple axes (Uniaxial Biaxial).
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TYPES OF GEOTECHNICAL INSTRUMENTS
Tilt sensors measure the tilting position with
respect to its original reference. It pro- vides
important information about both the vertical and
horizontal inclination tilt. The main purpose to
use a tilt sensor is to measure tilt changes in
structures due to construction activities such
as tunnelling, excavation and de-watering that
affect the ground that support the
structure. The tilt sensor works on the
Micro-Electro-Mechanical Systems (MEMS)
technology to provide a digital output.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Tilt Beam Sensors

Model EAN-31EL, EAN-31EL-B EAN-41EL-B Series of
Electrolytic Uniaxial Tilt Meters Beam Sensors

Model EAN-41M/EAN-42M (SDI-12) MEMS Beam Sensors
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EAN-70M Portable Tilt Meter

Model EAN-90M/92M Tilt Meter
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EAN-91M Tilt Meter

Model EAN-91M-B/EAN-93M-B MEMS Beam Sensors
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EAN-95MW Wireless Tilt Meter
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EAN-96MW Wireless Triaxial Tilt Meter

Model ESDL-30MT Tilt Meter with Automatic Data
Logger
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TYPES OF GEOTECHNICAL INSTRUMENTS
Strain Gauges Strain Gauges are one of the vital
geotechnical sensors that measure strain in
under- ground cavities, tunnels, buildings,
concrete, masonry dams, bridges, embedment in
soil/concrete etc.
Any basic strain gauge sensor consists of an
insulating flexible metallic foil backing. To
measure the stress, the strain gauge is attached
to the object using an adhe- sive/welding.
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TYPES OF GEOTECHNICAL INSTRUMENTS
The deformation in the object causes the change
in frequency of the vibrating wire. Strain
gauges offer the ability to measure the effect of
loads, settlement or other changes in a
structure. They record strain, which is a
dimensionless measure of deformation. Stress is
related to strain by a materials properties and
is predictable within a certain range of applied
strain.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of strain gauges

Model EDS-11V Hermetically Sealed Vibrating Wire
Strain Gauge

Model EDS-12V Vibrating Wire Sister Bar Strain
Meter
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDS-20V SW Vibrating Wire Spot Weldable
Strain Gauge

Model EDS-20V-AW Vibrating Wire Arc Weldable
Strain Gauge
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TYPES OF GEOTECHNICAL INSTRUMENIMTSPORTANT?

Model EDS-20V-E Vibrating Wire Embedment Strain
Gauge

Model EDS-21V-AW Arc Wieldable Strain Gauge
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDS-21V-E Embedment Strain Gauge
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TYPES OF GEOTECHNICAL INSTRUMENTS
Load Cells Load Cells are a type of transducer
that converts force into measurable electrical
output. However, they dont work without being
paired up with external sensors such as strain
gauges.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Strain Gauges are thin elastic material made up
of stainless steel and are fixed inside the load
cell. The force exerted on the load cell tends to
deform the strain gauge. This deformation
causes a change in resistance which is then
converted to the read- able unit to determine
the weight of an object.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Load Cells

Model ELC-150S-H High Capacity Compression Load
Cell

Model ELC-210S Resistive Strain Gage Type
Compression Load Cell
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TYPES OF GEOTECHNICAMLOINSITTORRUIMNGENIMTSPORTANT
?

Model ELC-30S Resistive Strain Gage Type Center
Hole/Anchor Bolt Load Cell

Model ELC-30S-H Resistive Strain Gage Type Center
Hole/Anchor Bolt Load Cell
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model ELC-32V Vibrating Wire Center Hole-Anchor
Bolt Load Cell
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TYPES OF GEOTECHNICAL INSTRUMENTS
Pressure Cells A pressure sensor is a transducer
which converts pressure into a measurable
electrical output.
The main purpose to use a pressure cell is to
measure total stress in various construction
fields or the amount of stress being
transferred. The vibrating wire pressure
transducer works on the vibrating wire technology
to provide a digital output.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of pressure cells

Model EPS-30V-C Concrete Pressure Cell

Model EPS-30V-I Soil and Rock-Concrete Interface
Pressure Cell
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EPS-30V-C Concrete Pressure Cell

Model EPS-30V-I Soil and Rock-Concrete Interface
Pressure Cell
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model ESC-30V Shotcrete-Concrete Stress Cell
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TYPES OF GEOTECHNICAL INSTRUMENTS
Extensometers or Extension-Meters An
extensometer is a high precision instrument
specially designed for geologists or civil
engineers to measure the elongation of a material
under stress.
The instrument is perfect for tensile tests. It
can also determine yield strength, tensile
strength, yield point elongation, strain-hardening
exponent, and strain ratio, tensile strength,
yield point elongation, strain-hardening
exponent and strain ratio.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Extensometers

Model EDS-63U-D Mechanical Borehole Extensometer
System

Model EDS-64U-D Mechanical Borehole Extensometer
System
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDS-70V Electrical Borehole Extensometer
System

Model EDS-91 Magnetic Extensometer System
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDS-92 Soil Extensometer

Model EMA-11 Measuring Anchor/Rock Bolt
Extensometer
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TYPES OF GEOTECHNICAL INSTRUMENTS
Temperature Sensors A temperature sensor is a
device that is designed to measure the degree of
hotness or coolness in an object.
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TYPES OF GEOTECHNICAL INSTRUMENTS
The working of a temperature meter depends upon
the voltage across the diode. The temperature
change is directly proportional to the diode's
resistance. The cooler the temperature, lesser
will be the resistance, and vice-versa. The
resistance across the diode is measured and
converted into readable units of temperature
(Fahrenheit, Celsius, Centigrade, etc.) and,
displayed in numeric form over readout
units. In geotechnical monitoring field, these
temperature sensors are used to measure the
internal temperature of structures like bridges,
dams, buildings, power plants, etc.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of temperature sensors

Model ETT-10V Vibrating Wire Temperature Sensor

Model ETT-10TH Resistance Thermistor Probe
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model ETT-10PT RTD Temperature Probe

Thermocouple
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TYPES OF GEOTECHNICAL INSTRUMENTS
Displacement, Crack Meter, Joint Meter A
displacement sensor is designed to measure linear
displacement by converting mechanical motions
into readable electrical signals.
Crack Meters (crack width meter) and Joint Meters
are position and displacement sensors/transducers
with anchors and ball joints.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Displacement, Crack Meter, Joint Meter

Model EDJ-40C Crack Meter

Model EDJ-50V Vibrating Wire Joint Meter
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDJ-41M Crack Meter

Model EDE-VXX Vibrating Wire Linear Displacement
Transducer
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TYPES OF GEOTECHNICAL INSTRUMENIMTSPORTANT?

Model EDE-PXX Potentiometric Linear Displacement
Transducer

Model EDJ-40V Crack/Joint Meter
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDJ-40T Electrical Triaxial Crack/Joint
Meter

Model EDJ-40TJ Mechanical Triaxial Crack/Joint
Meter
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TYPES OF GEOTECHNICAL INSTRUMENTS
Readout Units A readout unit is a microprocessor
that displays the output data.
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TYPES OF GEOTECHNICAL INSTRUMENTS
It can be connected to several geotechnical
instruments to record the readings that can
either be uploaded to a host computer or printed
out on any text printer using the serial
interface. Being the worlds leading
manufacturers and suppliers of digital readout
for geotechnical sensors, Encardio-Rite deals
with two different robust, accurate, rugged,
reliable, and low-cost digital readout systems.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Readout Units

Model EDI-53 Portable Read-Out Unit/Data Logger

Model EDI-54V Vibrating Wire Indicator
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TYPES OF GEOTECHNICAL INSTRUMENTS
Geodetic Targets Survey Markers Geodetic
targets are extensively used for measurement of
deformation during tunnelling and subway
construction, and for monitoring displacement of
a bridge, dam, slope or building structure.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of Geodetic Targets Survey Markers

Model ERT-10B Bi-Reflex Target

Model ERT-10P2 Prism Target
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TYPES OF GEOTECHNICAMLOINSITTORRUIMNGENIMTSPORTANT
?

Model ERT-20P2-M1 Mini Prism Target

Model EBS-16 Building Settlement Point
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EPS-12 Pavement Settlement Point

Model ESMP-10/ESMP-11Ground Settlement Point
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TYPES OF GEOTECHNICAL INSTRUMENTS
Model EAWS-101 Automatic Weather
Station Encardio-rite Model EAWS-101 automatic
web based weather monitoring station provides a
precise, reliable and cost effective means of
recording meteorological data.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Encardio-rite offers weather system with standard
sensors for essential parameters as briefly
outlined below

Rain gauge
Model ERG-200/201 tipping bucket type rain gage
with stainless steel housing.

Wind speed and direction sensor
Model EWV-101S three cup anemometer wind speed
sensor along with Model EWV-101D wind direction
sensor with dynamically balanced wind vane
(coupled to a low torque potentiometer) gives
precise wind velocity.

Relative humidity temperature
Model EWH-101T performs both relative humidity
temperature measurement (with Pt 100).
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TYPES OF GEOTECHNICAL INSTRUMENTS
The multi plate radiation shield protects the
sensors from direct and reflected solar
radiation, thus minimizing error.

Data logger
Provides unattended monitoring recording. Other
sensors are also available on request. The
weather station can be configured based on
parameters to be measured or sensors
required. It handles all data processing
requirements, starting with collection and
storage of data, performing required
calculations on data, presenting results in
graphical and numerical format and generating
alarm messages.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Data Loggers The data loggers or data recorders
are the microprocessor-based, battery-operated
devices that are used to log real-time data from
various geotechnical sensors and display them in
a readable format.
The data loggers are a stand-alone device and
they are used to keep a constant check on the
structures health monitoring parameters such as
pressure, strain, stress, water level,
temperature etc.
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TYPES OF GEOTECHNICAL INSTRUMENTS
Types of data loggers

Model ESDL-30 Data Logger with SDI-12 Interface

Model ESCL-10VT Single Channel Data Logger
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model EDAS-10 Automatic Data Acquisition System
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TYPES OF GEOTECHNICAL INSTRUMENTS
Water Level Monitoring

Model EWLR-101Automatic Groundwater Level
Monitoring
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TYPES OF GEOTECHNICAL INSTRUMENIMTSPORTAN

Model ECTD-30V, ECTD-60V Conductivity Sensor with
Water Level and Temperature

Model ERG-200/201 Rainfall Gage
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TYPES OF GEOTECHNICAL INSTRUMENTS
Settlement

Model EGS-30V Settlement Measurement System
EGS-30V settlement measurement system is designed
for monitoring settlement in fills, embankments
and dams, etc.
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TYPES OF GEOTECHNICAL INSTRUMENTS
It comprises of a vibrating wire sensor connected
to a reservoir via a fluid filled polyethylene
sheathed twin nylon tubing. The sensor is
installed in soil fill and the reservoir is
mounted on firm ground. As the sensor settles
with surrounding soil, the fluid head at the
sensor increases. The change in measured head is
the settlement relative to the reservoir. A
manifold system is optionally available to
connect up to seven sensors to the same
reservoir.
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TYPES OF GEOTECHNICAL INSTRUMENTS

Model ESM-30V Liquid Level Settlement System
ESM-30V is a high sensitivity liquid level
settlement measuring system that uses low range
vibrating wire force transducer with a
submersible cylinder suspended in a fluid filled
vessel.
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TYPES OF GEOTECHNICAL INSTRUMENTS
It is designed for remote measurement of minute
differential settlement in tunnels, bridges and
buildings etc. with high precision. Settlement
of any vessel installed, causes change in its
fluid level, affecting the buoyancy on the
suspended cylinder. The ESM-30V is provided with
two or more settlement systems with fluid filled
ves- sels interconnected in series by a fluid
filled tube.
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