USE OF AN OSMOTIC PUMP TO CREATE A FLOWING REFERENCE JUNCTION FOR IONIC-ACTIVITY SENSORS

摘要

In an ionic-activity sensor, an osmotic pump drives a reference-cell electrolyte to flow through an interface with the solution to be measured. This minimizes contamination of the reference cell by that solution. The driving force results from expansion of an electrolytic-agent reservoir into which solvent from a solvent reservoir diffuses through a semi-permeable membrane. The electrolytic-agent reservoir contains an electrolytic-agent solution in which a quantity of undissolved is disposed to keep the electrolytic-agent solution saturated as solvent diffuses into it.