Slide rule to evaluate non meter readings - for concentration measurements

摘要

A circular slide rule has been specially designed, based on Nernst's equation, to eliminate any mathematical calculations when determining the concentration of a cpd. in a soln by ion-sensitive electrodes. The potential in the soln is measured, followed by the potential after ions have been added or subtracted. The two potential readings are used to set the inner logarithmic dial and the desired concentration can be read off on the outer dial.