PUBLICATION

Electrometric Methods and Apparatus

FOR DETERMINING

Hydrogen Ion Concentrations

CONTENTS

General Considerations-The Working Formulas-Electrometric Methods Applicable to Hydrogen Ion MeasurementsMethods Employing the Potentiometer Principle-Practical Considerations in Applying Working Formulas-Applications of the Gas Chain to Totration Analysis-Industrial Applications of Gas Chain Methods-Bibliography-Price List.

This new publication, Catalog Q-75, devotes 24 pages to a discussion in simple terms of the general questions pertaining to hydrogen ion concentrations and their measurement by electrometric methods. It explains pH, the "hydrogen ion exponent," its relation to hydrogen ion concentration, and the method for converting one to the other. It shows how the working formulas. are obtained from Nernst's equation, and what precautions to observe in applying them. There is a section dealing with the different methods by which gas chain voltages may be measured without polarizing the source, and the advantages or limitations of each. A selected bibliography gives references to many original articles dealing with various chemical and biological problems to which gas chain methods have been applied. A price list of individual instruments and assembled outfits affords a wide choice, from which an equipment, suited to the particular needs of the user, may be selected,

If, in asking for your copy of Catalog Q-75, you will tell us about the kind of work in which you are especially interested, it will enable us in the future to send you those of our publications which will prove valuable to you.

LEEDS & NORTHRUP COMPANY

ELECTRICAL MEASURING INSTRUMENTS

4901 STENTON AVE.

PHILADELPHIA, PA.