HND-C110
HND-C110 K05/0422
page 11
9.5 Salinity measuring
The salinity (salt content) of seawater can be determined in the measuring mode
„SAL“ (basis: International Oceanographic Tables; IOT)
The salinity of standard-seawater is 35 ‰ (35 g salt per 1 kg seawater).
The values are displayed in ‰ (g/ kg).
Additionally, the term “PSU” (Practical Salinity Unit) is sometimes used, the
displayed value is the same. The salinity measurement has its “own” temperature
compensation, i.e. the temperature is automatically taken into account for the
salinity measurement. The menu settings regarding the temperature
compensation are ignored.
Attention: The salt composition of the different seas is not the identical.
Depending on place, weather, tides, etc. there may be considerable
divergences to the 35 ‰ according to IOT. Additionally, the salt
composition may influence the ratio between salinity and actual salt
content.
9.6 Electrodes / measuring cells
9.6.1
Design
Basically, there are two types of measuring cells: 2-pole and 4-pole cells. The
operation is done similarly; the 4-pole measuring cells can compensate
polarization effects and – up to some degree – soiling due to its complex
measuring method.
9.7 Temperature compensation
The conductivity of aqueous solutions depends on its temperature. The
temperature dependency is strongly dependent on the type of solution. The
temperature compensation recalculates solutions’ conductivity to a consistent
reference temperature. The most common reference temperature is 25 °C.
