Secchi Discs are designed for the measurement of
the relative turbidity and clarity of a body of
water. This disc is constructed of PVC and is
finished in alternating black and white quadrants of
acrylic paint. The disc operates as such: the disc
is lowered into the water on a graduated line. The
depth at which the disc is no longer visible is
recorded. The disc is then raised, and a recording
of the depth at which the disc reappears should be
made. The mean of these two recordings is considered
to be the limit of visibility. Although the disc is
unable to provide an actual measure of light
penetration, it is useful in providing a rough index
of visibility for comparative purposes available in
a kit that includes a weighted, 20 cm (8") diameter
Secchi disc with black and white quadrants, 20 m
uncalibrated nylon line on foam spool, and
instructions.
605-015 Secchi Disc -
20 cm (8") in diameter
2 lbs.
605-016 Secchi Disc
Kit 5 lbs.
