LaMotte BOTTOM SAMPLING DREDGE 1097 - Manual (Page 2)

Whenever samples of the bottom are taken, every effort must be made to
insure that the samples are truly representative of the whole area. Much of
this depends upon the judgment of the individual taking the sample and
their individual study objectives. Ordinarily, take as many samples as
practical, since one sample has no value statistically. The time interval
between sampling and analysis is not critical for a mechanical or physical
analysis, but analysis is recommended for both biological and chemical
examinations.
IN STRUC TIONS FOR USE
The Bottom Sampling Dredge is shipped completely assembled. The
dredge has a bridle that reaches between the tips of the stainless steel arms
of the dredge. A line should be securely attached to the middle of the
bridle to retrieve the dredge from the bottom. When the dredge is lifted by
the bridle, the jaws of the dredge draw shut. When the arms are pushed
apart, the jaws of the dredge open. A rocking trigger mechanism attached
to the arms holds the dredge open. Holes in the upper part of the
collection chamber let air escape from inside the chamber as it is lowered
through the water.
1.
Push arms apart, opening the dredge. Raise the rounded end of the
locking trigger mechanism and place tension on the retrieving line,
raising the dredge arms until the trigger catches in the notch on one
of the arms. The dredge will remain open as long as tension is
maintained on the bridle.
2. Lower the dredge through the water, keeping tension on the
retrieving line, until the dredge contacts the bottom.