MEASURING WELLS

Press, Volume CII, Issue 30155, 12 June 1963, Page 12

MEASURING WELLS

This refinement of the water diviner’s willow wand is the work of the industrial development department of he University of Canterbury. It is an electrically-sensitive well-depth indicator, which enables the water level in an artesian bore to be checked o within an inch for up to 100 ft underground. Most parts of Canterbury are well served with artesian water, but the depth of streams below the surface is difficult to guess, and the periodic changes in water levels can cause wells to become dry. To help to avoid this, the local officers of the Ministry of Works maintain a reference table of the periodic rises and falls in bores throughout Canterbury, and

the new equipment will help considerably in this work. The indicator is fitted over a bore pipe and a steel cable wound out* its length accurately measured by a counter running off the cable's guiding wheel The cable has an insulated conductor in its core, and an electric circuit is completed when the sensor at the cable's end is immersed in water. A dry-cell torch battery in the unit is sufficient to wofk the indicator dial immediately contact with water is made, and the level of the sensor can be adjusted to the exact water level. Previous equipment used a double plastic-coated wire with distances marked on it but this stretched enough to upset readings considerably at greater depths.