Abstract

Electrometric and colorimetric methods are the two classical methods for the pH determination. In the first case the traditional instruments, used to measure pH of a solution, is the glass electrode; it tipically consists of a glass tube sealed at one end by a special ion-selective glass, filled with a reference electrolyte and connected with a high input resistence voltmeter. The colorimetric method is based on absorption, using indicators that reveal the acid or base character of a solution through a change of colour; another phenomenon which can be utilized is fluorescence, by using particular substances whose fluorescence varies with the acidity of the solution.

© 1986 Optical Society of America