Hanna Instruments HI 4321 - Manual (Page 49)

49
PRACTICAL SALINITY SCALE (UNESCO 1978) PRACTICAL SALINITY SCALE (UNESCO 1978) PRACTICAL SALINITY SCALE (UNESCO 1978) PRACTICAL SALINITY SCALE (UNESCO 1978) PRACTICAL SALINITY SCALE (UNESCO 1978)
According to the definition, salinity of a sample in psu (practical salinity units) is calculated using the
following formula:
where:
R
T
- coefficient;
C
T
(sample) - uncompensated conductivity at T °C;
C(35,15)= 42914 µ S/cm - the corresponding conductivity of KCl solution containing a mass of 32.4356 g
KCl / 1 Kg solution;
r
T
- temperature compensation polynom
a
0
=0.008 b
0
=0.0005
a
1
=-0.1692 b
1
=-0.0056
a
2
=25.3851 b
2
=-0.0066
a
3
=14.0941 b
3
=-0.0375
a
4
=-7.0261 b
4
=0.0636
a
5
=2.7081 b
5
=-0.0144
c
0
=0.008
c
1
=0.0005
X=400R
T
Y=100R
T
f(T)=(T-15)/[1+0.0162(T-15)]
Note: The formula can be applied for salinity values between 0 and 42 psu.
The formula can be applied for temperatures between -2 °C and 35 °C.