hello ........ pls i would love to know if there is an ardiuno sensor that could be used for salinity, now i have heard the water level sensor could also be used for this purpose but i still haven't figured out how this could be done
pls i would really love to here suggestions/comments on this issue thanks
P/S i am still new at this (electronics and programming)
For high salt (4000ppm) you could measure the current between 2 titanium electrodes. Need about 7v @ 1A (depends on the size of the electrodes).
For liquid resistivity measurement you use low currents, since you definitely don't want any
electrochemical reactions going on - 7V is vastly above the chemical potential of water so you'd just generate
hydrogen and chlorine and poison yourself..
You use a small (< 1V) ac voltage source and measure the current, and thus compute the resistivity/conductivity using the geometry of the test-cell. Easiest to do the geometry for
close parallel plates or two parallel circular rods. ac is needed to avoid polarization.