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According to the definition, salinity of a sample in PSU (practical salinity units) is calculated using
the following formula:
S=-0.08996+28.212.80832R
2
–10.67869R
3
+5.98624R
4
–1.32311R
5
where:
R
T
- coefficient;
C
T
(sample) - uncompensated conductivity at T °C;
C(35;15)= 42.914
mS/cm - the corresponding conductivity of KCl solution
containing a mass of 32.4356 g KCl / 1 Kg solution;
r
T
- temperature compensation polynom.
Note: The formula can be applied for temperatures between 10
°
C and 31
°
C.
To access this range press Mode while in Salinity range until the seawater scale [SW] is
displayed.
Practical salinity scale
This is a practical scale based on the precise measurement of the electrical conductivity of a solution
with a known salinity range.
The relationship derived from the scale relates salinity, conductivity, temperature and pressure
and use a solution with a salinity of 35 ‰ as datum point. This is taken to have a conductivity
of 42.914 mS/cm of 15 °C at standard atmospheric pressure.
OPERA
TIONAL GUIDE
