Since 1930 the Petersen grab has
been used in fresh water for collecting macroscopic fauna in sand,
gravel, marl, clay or clay combinations. If used in salt water, it
must be painted for protection. Since it has been widely used over
6 decades, it is ideal for comparing samples with data collected previously
by a Petersen grab. Vent holes permit water to flow through while
the grab is being lowered, minimizing diagonal movement as well as
reducing the frontal shock wave generated by descent. Jaws close clamshell
fashion.
We include a safety-pin to prevent the scoops
from closing to help prevent injury. The bayonet-style trip mechanism
is designed to release only when the sampler is on the bottom and
the cable is slack. A deliberately heavy device for biting deep into
hard bottoms. Can hold up to 8 removable weights. Operation requires
winch and crane due to the working weight. Ship wt: 115 lbs.
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