Continuous Oxygen Recording in Seawater
Abstract
Summary of the results and experiences obtained during the work with the
oxygen recorder.
The apparaus is very simple to build and use, and it works rapidly.
It is possible by means of this apparature to take continuous readings
of the variations of oxygen content in the water downward from the
surface. The readings give a picture which is available immediately, and
which may be useful for the marine biologist working at sea.
For hydrographic work it may be of interest that the recorder indicates
the depths where the oxygen content changes rapidly, which may
be important in deciding where to take additional observations.
With a few determinations of the oxygen content by the usual
method it is possible to obtain a linear calibration diagram (see Fig. 3)
by means of which the oxygen content at various depths can be determined
with fairly good accuracy. It is recommended that anyone who
starts using the apparatus should at the beginning make usual Winkler
determinations of the oxygen content whenever the oxygen recorder
is used. This is necessary because the ammeter values are dependent
on the purity of the mercury and on the speed of the falling drops. The
calibration curve, therefore, will not always go through zero.
In water with sharp discontinuity layers it should never be possible
lo determine salinity and oxygen content of such layers by means of the
usual with any accuracy at all. This is because the water sampler
itself is so long that it collects water of greatly varying properties. In such
discontinuity layers only continuous recording can give the correct
picture.
Fig. 4 gives examples of curves obtained by the oxygen recorder.
Publisher
[Fiskeridirektoratets havforskningsinstitutt]Series
Fiskeridirektoratets skrifter, Serie Havundersøkelservol 11 no 3