Hydraulic Overflow Settlement Monitoring System

Model EHOS-35 Overview

The model EHOS-35 hydraulic overflow settlement system is suitable for measurement of settlement or heave in an embankment of a dam or infills where the settlement cell (sensor) and terminal structure or observation room can be nearly at the same elevation.

The hydraulic overflow settlement gage works on the ā€˜Uā€™ tube principle. It consists of a graduated standpipe and a sealed settlement cell with three accesses - first for an overflow pipe which is connected by a nylon tubing to the standpipe, second allows the drainage of excess water from the cell and the third access allows atmospheric pressure to be maintained inside the cell. The cell is installed in soil fill and the standpipe on the firm ground outside the structure. De-aired water is filled in the standpipe and tubing connecting it to the cell. Comparing the water level in the standpipe with earlier readings taken gives the settlement/ heave to which the cell is subjected.

Key components


Standpipes are available in suitable length (settlement range + 0.5 m) depending on settlement expected.
Settlement cell capacity depends on the volume of the water contained in the tubing connecting the cell to the level indicator. Depending upon tubing lengths up to 60 m, 150 m and 300 m, cells are available in capacities of 2, 5 and 10 litre respectively.
Dual nylon tube of 6 mm o.d. x 4 mm i.d. (pressure rating of 3.5 MPa).., one black and one white of uniform cross-section enclosed in polythene sheathing.
Nylon tubing 8 mm o.d. x 5 mm i.d. (pressure rating of 3.5 MPa) in a suitable length for the drain
De-aired water in 5, 10 or 20-litre container
Mono-block 0.25 HP centrifugal pump operating on single phase 230VAC
Foot pumps (optional to EHOS-35/6.1)


Measured range (m)
1, 1.5, specify
1 mm
Fluid & Vent tubing
6 mm o.d., 4 mm i.d. twin nylon tube
Drain tubing
8 mm o.d., 5 mm i.d. nylon tube

Hydraulic Overflow Settlement Monitoring System
Hydraulic Overflow Settlement Monitoring System