5 | Measurement Basics
G 1400 series
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B-H87.0.0X.DK2-3.0
With selection of TDS, the necessary temperature compensation is selected
automatically. Menu settings for temperature compensation are ignored.
The following approximations apply:
CtdS
0,50
Monovalent salts with 2 ion types = NaCl, KCl or similar
0,50
Natural water of surface water, drinking water
0,65 bis 0,70
Salt concentration of aqueous fertiliser solutions
NOTE
These are guideline values for estimates, but are not suitable for precise
measurements. The conversion factor for the respective type of solution and the
examined concentration range must be determined for precise measurements. This
can take place with calibration to known comparison solutions or with actual
evaporation of a certain amount of liquid with measured conductivity and subsequent
weight of the total dissolved solids.
5.4
Salt content / salinity measurement
(only available at G 1410)
In SAL measuring mode, the salinity, which is the salt content of sea water, is
determined. The basis for this is the International Oceanographic Tables, IOT.
Standard salt water has a salinity of 35 ‰, 35 g of salt per 1 kg of sea water. The
display in % [g/kg] normally does not show units. The designation PSU, Practical
Salinity Unit, is also commonly used; the display value is identical. The salinity
measurement has temperature compensation, which means the temperature is
considered for the display and has a major influence on the display value; any menu
settings regarding temperature compensation are ignored.
NOTE
The salt composition of different seas is not identical. Depending on the location,
weather, seasons, etc., there are considerable deviations from the 35 ‰ according to
the IOT. The salt composition can also influence the relationship of the salinity display
and the actual amount of salt present.
Corresponding tables are available for many salts in salt water aquarium applications.
Salt weight to salinity according to the IOT or conductivity. In consideration of these
tables, very precise salinity measurements can be conducted.
