Subject: How to determine salt content in water using electricity?

A molecule of table salt is made up of a sodium atom and a chlorine atom. 
A lone sodium atom has one more electron than necessary for stability, and 
a chlorine atom has one electron too few. So the sodium atom donates its 
electron to the chlorine atom. This leaves the sodium atom positively 
charged and the chlorine atom negatively charged, and the two stick 
together electrostatically. Salt water has a ton of mobile charged objects 
(the sodium and chlorine ions) that can flow in the direction of an 
electric field, creating a large current. However, all the research I have 
done did not specify how to determine the CONTENT of salt in the water 
solution.

Re: How to determine salt content in water using electricity?