A salt test using crystalline salt is only qualitative. It can be made quantitative by using a (very) dilute saline solution instead of solid salt. It is just a matter of dissolving a known mass of NaCl in DW (it's best to use the same batch of DW as is used to make the EIS) and diluting it in stages to a known millimolar to micromolar concentration.
As a check, one could use ice-melter (calcium chloride, CaCl) or water-softener (potassium chloride, KCl) or muriatic acid (hydrochloric acid, HCl) instead of table salt (sodium chloride, NaCl) dissolved and diluted to the same order of magnitude of micromolarity as the ionic fraction of silver in the EIS. Then add EIS to the chloride solution(s) of known micromolarity and measure the rate of decline of conductivity in the mixture. The micromolarity of the ionic fraction of EIS can then be determined without expensive equipment. Nineteenth century glassware (or their plastic 20th century equivalents) can do the job. After all, the pioneers of CS did a lot of good scientific research on CS before the birth of electronics (Lee de Forest's triode centennial is next year.) Best regards, Matthew
