34
Rev. 1.0 31/01/2020
EN
Never clean it mechanically, this would damage the electrodes compromising the functionality.
For short periods, store the cell in distilled water, while for long periods, keep it dry.
Other measurements carried out with the Conductivity cell
The conductivity measurement can be converted into the TDS and Salinity parameters.
•
In measure mode, press the key
to scroll through the various parameters
TDS -> Salinity.
•
These parameters use the Conductivity calibration; therefore, refer to the previous paragraph to
calibrate the sensor.
•
TDS Parameter
COND 60 VioLab, PC 60 VioLab
Total Dissolved Solids (TDS) correspond to the total weight of the solids (cations, anions and non-dissociated
substances) in a liter of water. Traditionally, TDS are determined using the gravimetric method, but a simpler
and faster method is to measure Conductivity and convert it to TDS by multiplying it by the TDS conversion
factor.
•
In measure mode press
to access the SETUP menu.
•
Use the directional keys to move to
TDS SETTINGS P4.0
and access the menu by pressing the key
.
•
Press again
to enter the program
TDS FACTOR P4.1
•
When the value flashes, use the directional keys as indicated by the icon
to enter the correct value
and confirm with
.
By default, the TDS factor is set at 0.71; the user can change it between 0.40 ... 1.00.
Here below, the TDS factors in relation to the Conductivity value are shown:
Conductivity of the solution
TDS Factor
1-100 µS/cm
0.60
100 – 1000 µS/cm
0.71
1 – 10 mS/cm
0.81
10 – 200 mS/cm
0.94
The TDS measurement is expressed in mg/l or g/l depending on the value.
•
Salinity
COND 60 VioLab, PC 60 VioLab
Usually the UNESCO 1978 definition is used for this parameter, which involves the use of the psu unit of
measurement (Practical Salinity Units), corresponding to the ratio between the conductivity of a sample of
sea water and one of a standard KCl solution formed by 32.4356 grams of salt dissolved in 1 kg of solution
at 15 ° C ratios are dimensionless and 35 psu equals 35 grams of salt per kilogram of solution. So
approximately 1 psu equals 1g / L of salt and considering the density of the water it equals 1 ppt.
