COMPOUND* TESTING IMPLEMENT AND TESTING METHOD FOR MEASURING ION INTENSITY OR SPECIFIC GRAVITY OF LIQUID SAMPLE* AND METHOD OF MAKING TESTING IMPLEMENT

摘要

A system for determining the ionic strength or specific gravity of an aqueous test sample comprises a weakly acidic or weakly basic polyelectrolyte which is at least partially neutralized, and an indicator means capable of producing a detectable response to ion exchange between the polyelectrolyte and the sample. A test device comprises a carrier matrix incorporated with a test composition comprising the polyelectrolyte, and the method for its use comprises contacting an aqueous test sample with the device and observing a detectable response, for example a colour change of an indicator such as bromothymol where originally included in the device, or a change in pH measured using a flat surface electrode.