EARTHEN DAM INSTRUMANTATION

1. SOIL STRAIN METER:

APPLICATIONS:

Typical applications include:

•          Monitoring horizontal strain in embankment dams.
•          Monitoring tension cracks in earth structures.
•          Stainless model for monitoring strain in rock fill dams.

OPERATION:

The soil strain meter 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 strain meter is used as a datum. Subsequent readings are compared to the datum to calculate the magnitude, rate, and acceleration of movement.

Strain meters are usually installed in series along the axis of anticipated deformation. Strain meters 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.

There are two models of the strain meter available: the standard strain meter for soils and the stainless-steel strain meter for rock fill dams.

ADVANTAGES:

         1      EASY INSTALLATION: 

               The strain meter is designed for easy assembly, easy extension of gauge lengths, and easy adjustment.

         2      REDUCED CABLE COSTS: 

               The double-sensor version provides cable economies since a single length of cable can serve two sensors and two gauge lengths.

          3      MANUAL OR AUTOMATIC READOUT: 

                Strain meters can be read manually with a portable indicator or can be connected to a data logger for unattended readings.

         4      STANDARD OR STAINLESS: 

                The standard model is designed for use in soil embankments, and the stainless model is designed for use in rock fill dams.

2. SETTLEMENT SENSOR:

The Settlement System is designed for the remote measurement of surface or subsurface settlement in fills, surcharges, dams, embankments, etc. A borehole is drilled which allows a pressure transducer to be anchored to solid ground below the area of settlement. A fluid filled tube extends upward connecting the transducer to a reservoir which is located in the moving strata or fill. The measurement of fluid pressure indicates the elevation difference between the sensor and the reservoir. This design eliminates the need for long liquid filled tubes. Systems capable of measuring at multiple levels are also available.

3. HEAVY-DUTY PIEZOMETER: 
 This piezometer is a variant of the standard borehole piezometer. It features a thick-walled stainless steel body and is supplied with double-jacket armored cable.

4. TEMPERATURE GAUGES:

With substantial industrial experience, we have emerged as a renowned manufacturer and exporter of temperature gauges. Our range includes bimetal temperature gauge, mercury gas filled temperature gauge capillary type and temperature recorder. Easy to mount on stem, panel and surface mercury gas filled temperature gauge capillary type is widely used for accurate measurement of temperature. Our temperature recorder has gained wide appreciation for its ability to efficiently function in complex temperature conditions.

TYPES OF TEMPERATURE GAUGES:

                        i.            BI-METAL TEMPERATURE GAUGE:

We are one of the reputed manufacturers and exporters of Bi-metal Temperature Gauge that finds wide application in food and beverage industries. Highly reliable the rugged bi-metal helix is properly heated and coated with viscous silicon to improve temperature transmission and minimize pointer oscillation. A popular temperature measuring instrument, it finds wide application in hot water boiler, power plant, domestic & industrial heating system and pharmaceutical industry.

                         ii.            TEMPERATURE GAUGE STEM TYPE:

We are engaged in offering mercury gas filled Temperature Gauge Stem Type that has gained wide appreciation for accurate temperature measurement. This gauge is made using bulb, transmitting capillary and flat bourdon tube that are pressure filled with Mercury. This economical, rugged and reliable temperature measuring instruments is available in 80, 100, 150, 200, 250, 300 mm sizes.  These gauges can be easily mounted on stem, panel and surface.

                         iii.            TEMPRATURE GAUGE CAPILLARY TYPE:

Meeting the demands of several industries, we offer mercury gas filled Temperature Gauge Capillary Type. Fabricated using quality raw material, it is widely used for accurate measurement of temperature.  These gauges can be easily mounted on stem, panel and surface. Available in various sizes this capillary type gauge is widely appreciated for accuracy and durability.

5. EARTH PRESSURE CELLS:

The Earth Pressure Cells are designed to measure total pressure in earth fills and embankments. All cells consist of two circular stainless steel plates welded together around their periphery and spaced apart by a narrow cavity filled with de-aired oil. Changing earth pressure squeezes the two plates together causing a corresponding increase of fluid pressure inside the cell. A vibrating wire pressure transducer converts this pressure into an electrical signal which is transmitted to the readout location.

6. PIZOMETER:

The Standard Piezometer is designed to measure fluid pressures such as ground water elevations and pore pressures when buried directly in embankments, fills, etc. Also for installation inside boreholes, observation wells and standard (>19 mm diameter) piezometer riser pipe. The Model 4500SH is designed with a heavy duty housing for pressures that exceed 3 MPa. The Model 4500AL is designed for low-pressure ranges. The vented version (ALV) provides automatic compensation for barometric pressure changes. Thermistors are included to measure temperatures.

7. IN-PLACE INCLAINO METER:

The In Place Inclinometer (IPI) is designed for near vertical borehole applications, the principal operation and data obtained are similar to the traversing type inclinometer systems such as the portable Digital Bluetooth Inclinometer systems. Typical applications of the IPI system include the monitoring of landslide areas, stability of natural slopes and Dams, railroads, highways, landslide areas and early warning of a pending slope failure, ground movements due to tunnel construction and excavation as well as monitoring deformations of embankments and retaining walls.

The system utilizes a fixed string of inclinometer probes separated by rigid gauge tubing, the main advantages include rapid automatic data logging and real-time monitoring. The IPI sensor incorporates a MEMS accelerometer making the instrument virtually shock proof, giving a high degree of repeatability and accuracy. The sensor incorporates an on-board microprocessor which performs an automatic temperature compensation of the tilt (g) data. The sensor is a very low power, low EMC device which conforms to the specifications laid down under EN50121 1-4, making it particularly suitable for work on or adjacent to railway lines and in tunnels.

8. INCLINOMETER PROBE:

Applications:

Digital inclinometers are used to monitor lateral movements in embankments and landslide areas, deflections of retaining walls and piles, and deformations of excavation walls, tunnels, and shafts.

Operation:

Inclinometer casing is typically installed in a near vertical borehole that passes through suspected zones of movement into stable ground. The Digital inclinometer probe, control cable, pulley assembly, and readout are used to survey the casing.

During a survey, the probe is drawn upwards from the bottom of the casing to the top, halted in its travel at half-meter intervals for tilt measurements (two-foot intervals are used for English probes). The first survey establishes the initial profile of the casing. Subsequent surveys reveal changes in the profile if ground movement occurs.

The inclination of the probe body is measured by two force-balanced servo-accelerometers. One accelerometer measures tilt in the plane of the inclinometer wheels, which track the longitudinal grooves of the casing. The other accelerometer measures tilt in the plane perpendicular to the wheels. Inclination measurements are converted to lateral deviations.

Changes in lateral deviation, determined by comparing data from current and initial surveys, indicate ground movements. Plotting the cumulative changes at each measurement interval yields a high resolution displacement profile. Displacement profiles are useful for determining the magnitude, depth, direction, and rate of ground movement.

9. PORTABLE READOUT BOXES:

The Model GK-404 Vibrating Wire Readout Box is a portable, low-power, hand-held unit that is capable of running for more than 20 hours continuously on two AA batteries. It is designed for the readout of all Geokon vibrating wire gages and transducers, and is capable of displaying the reading in either digits, frequency (Hz), period (µs), or micro strain (µε). The GK-404 also displays the temperature of the transducer (embedded thermistor) with a resolution of 0.1°C.

10. MULTIPLEXER:

Choose from the industry’s largest selection of analog multiplexers in leading-edge small packages. ADI offers multiple configurations from four channels to 32 channels in standard plastic packages as well as in space-saving LFCSP and WLCSP packages. Ron performance is industry-best, with the ADG708 series multiplexers offering 2.5 Ωtypical and ADG804 series < 1 Ω guaranteed over the full voltage range and temperature specification.

11. MULTICHANAL DATA LOGER:

Technically speaking, a data logger is any device that can be used to store data. This includes many data acquisition devices such as plug-in boards or serial communication systems which use a computer as a real time data recording system. However, most instrument manufacturers consider a data logger a stand-alone device that can read various types of electrical signals and store the data in internal memory for later download to a computer.
The advantage of data loggers is that they can operate independently of a computer, unlike many other types of data acquisition devices. Data loggers are available in various shapes and sizes. The range includes simple economical single channel fixed function loggers to more powerful programmable devices capable of handling hundreds of inputs. 

12. SEEPAGE MONITORS:

The measuring of seepage and movement is a fundamental element of dam surveillance. Some attempts have been made to provide alternative for seepage monitoring using fully distributed sensing along with optical fibers. The monitoring system offers important information for estimating the safety state of embankment dam. Both management system and upper management of the embankment dam depend on the information. However, this relatively newer monitoring system consists of hardware, software and configuration parts, which may be weak or non-effective within a data processing unit. Hence, reliability analysis of this seepage monitoring is necessary prior to building a standard criterion to decide if a serious seepage happens in the embankment dam. In this paper, the reliability of simulation unit, seepage control unit and sensing unit are analyzed, which is useful to ensure that the monitoring system works effectively.