Water Resources--Office of Water Quality

National Field Manual

6.4 pH

Version 1.3, dated 1/2006 (296 KB)

Abstract

Measurement of pH is critical to the understanding of the viability and vulnerability of environmental waters and is considered a master variable in determining the aqueous geochemistry of an aqueous system. pH is a measure that represents the hydrogen-ion concentration (activity) of a solution. This section of the National Field Manual (NFM) describes U.S. Geological Survey (USGS) guidance and protocols for measurement of pH in ground and surface waters.

Contents

6.4 - pH

By F.D. Wilde, Eurybiades Busenberg, and D.B. Radtke

6.4.1 Equipment and supplies

6.4.1.A pH buffer solutions

6.4.1.B pH electrodes: maintenance, reconditioning, cleaning, and storage