【国外标准】 Standard Test Method for Measuring Apparent pH of Electrocoat Baths

4.1 The pH is the measure of the free hydrogen ion concentration of a sample, and it indicates whether an electrocoat bath is acidic, neutral, or basic. Since pH measurements of good precision are made in aqueous solutions, it is suggested that the pH measurements of electrocoat baths are only semi-quantitative, and therefore such measurements should be referred to as apparent pH measurements.4.2 The pH of electrocoat paints is used for research, production, and quality control or electrocoat bath process control.4.3 Other related methods for determining the pH of water or aqueous systems are described in Test Methods D1293 and E70.1.1 This test method covers the measurement of the free hydrogen ion concentration of electrocoat baths and their ultrafiltrates.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This 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.1.4 This 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.