1.1This test method covers the continuous determination of pH of water by electrometric measurement using the glass, the antimony or the ion-selective field-effect transistor (ISFET) electrode as the sensor.

1.2This test method does not cover measurement of samples with less than 100 μS/cm conductivity. Refer to Test Method D5128.

1.3This test method does not cover laboratory or grab sample measurement of pH. Refer to Test Method D1293.

1.4The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.6This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.