RP-01638

GROUND LEVEL
A
B
Fig. 5. (A) Lift and (B) suction pumps: (1) wooden parts; (2) galvanized parts; (3) PVC parts; (4) mild-steel stand;
(5) concrete; (6) piston; (7) foot valve; and (8) casing pipe.
two rural areas in Malaysia. The objectives of
the field-testing program were to evaluate
the technical performance under field conditions
and the economic feasibility of wide-scale
adoption for rural use in Malaysia.
Measurement techniques for use in the field
A number of laboratory measurement
techniques for the determination of the
technical performance of the reciprocating
piston pump cannot be used in the field either
because sophisticated electronic equipment is
needed or because of physical constraints at
the handpump site. Several simple field measurement
techniques and apparatus were
developed for use in the field evaluation
program.
Depth of water table In this method, the
difference in the electrical resistance of water
and air is employed to detect the water level
in the well. The arrangement consists essentially
of a sufficient length of twin-core wire
and a perspex conical probe head. The twin
wires are threaded into the central hole of the
probe head and the ends of the wires enter
two lateral holes and emerge flush with the
surface on either side of the probe head. The
probe head is machined with a total conical
angle of 200 and the surface polished to facilitate
drip-dry action when the probe is lifted
out of the water. A multitest meter capable
of measuring in the range of up to 300 kohms
is connected to the other end of the twin-core
wire to measure the resistance across the two
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