Soil Extensometer

Model EDS-92 Overview

The EDS-92 soil extensometer is used for monitoring displacement between two surfaces that may shift with respect to each other. It is widely used for monitoring of soil and rock movement in embankments and dams.

The system contains a specially mounted model EDE-VXX vibrating wire displacement sensor, installed inside the protective tubing, fixed between two anchor beams with connecting rods. Any change in the relative position between the anchor beams represents deformation taking place and is measured by the displacement transducer.

The extensometer system is supplied with different gage lengths (gage length is the distance between two anchors).
A number of extensometer units can also be connected in series to measure incremental displacements over large distances. Movement of relative position between two anchor channels at the ends of the soil extensometer is representative of mass movement.

The frequency output can be accurately measured by any vibrating wire readout unit. The data can also be automatically collected at desired frequency, stored and transmitted to remote server by a suitable wireless datalogger. The initial reading of the sensor is taken as the base. Subsequent readings are then compared with the initial reading to determine the magnitude of change in displacement across the opening

Specifications

Sensor Type

Vibrating Wire

Range (mm)

15, 25, 50, 100, specify

Accuracy

± 0.2 % fs normal; ± 0.1 % fs optional

Sensitivity

± 0.02 % fs

Non-linearity

± 0.5 % fs

Temperature Limit

- 10°C to 80°C

Thermistor

YSI 44005 or equivalent (3 kOhms at 25°C)