Salinity; Specific Conductivity - RBR duo3 C.T uv Manual

5.1 Salinity

Salinity is defined as the ratio of the mass of dissolved material to the mass of seawater. It is impossible
absolute salinity directly. However, we can derive practical salinity from measurable properties: electrical conductivity,
temperature, and pressure, obtained by your RBRconcerto
(dimensionless Practical Salinity Units).
RBR uses the algorithm recommended by PSS78, the world standard for practical salinity calculation.
calculation of practical salinity in a range 2 to 42PSU from conductivity S (mS/cm) measured at temperature T (ºC) and
hydrostatic pressure p (dBar).
3 C.T | uv will calculate salinity if you enter depth in the table under the Parameters tab in
The RBRduo
Ruskin User Guide: Standard Instruments
.

If the PSS78 calculation generates an error, the instrument will report a salinity of 0. This might occur when, in
air, the conductivity report a small negative value. This does not apply if one of the measured parameters is
already flagged as an error.
.
.

5.2 Specific conductivity

Specific conductivity is a function of conductivity and temperature. This parameter is mostly applicable in studies of
freshwater and brackish water. The units of measurement are μS/cm (microsiemens per centimetre).
RBR uses the algorithm described in
al, which yields specific conductivity normalised to 25°C.
where conductivity in mS/cm and temperature in °C are values measured by your RBR instrument, and 0.0191 is the
default specific conductivity coefficient.
The specific conductivity coefficient is defined as the change in conductivity (in %) per 1°C. Its default value
corresponds to an increase in conductivity of 1.91%. However, it depends on temperature and ionic composition of the
water, ranging between
body of water in literature or experimentally. In this case, adjust the specific conductivity coefficient manually
table under the Parameters tab
This method enables calculation of specific conductivity in a range 0 to 6000μS/cm and is valid in the temperature
range -2°C to +35°C.
RBR#0015699revB
Refer to Practical Salinity Scale of 1978 (PSS78)
3
.
Standard Methods for the Examination of Water and Wastewater
0.0175 and 0.0214 for natural lakes and
in Ruskin. See Ruskin User Guide: Standard Instruments
3
C.T.D | uv. The units of measurement are
for more details.
rivers. You may be able to find the value specific to your
to measure
PSU
It enables
Ruskin. See
by L.S. Clesceri et
in the
3
.
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