ASTM D4584-05(2010)
(Test Method)Standard Test Method for Measuring Apparent pH of Electrocoat Baths
Standard Test Method for Measuring Apparent pH of Electrocoat Baths
SIGNIFICANCE AND USE
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.
The pH of electrocoat paints is used for research, production, and quality control or electrocoat bath process control.
Other related methods for determining the pH of water or aqueous systems are described in Test Methods D1293 and E70.
SCOPE
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 and health practices and determine the applicability of regulatory limitations prior to use.
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: D4584 − 05 (Reapproved2010)
Standard Test Method for
Measuring Apparent pH of Electrocoat Baths
This standard is issued under the fixed designation D4584; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope good precision are made in aqueous solutions, it is suggested
that the pH measurements of electrocoat baths are only
1.1 This test method covers the measurement of the free
semi-quantitative, and therefore such measurements should be
hydrogen ion concentration of electrocoat baths and their
referred to as apparent pH measurements.
ultrafiltrates.
4.2 The pH of electrocoat paints is used for research,
1.2 The values stated in SI units are to be regarded as
production, and quality control or electrocoat bath process
standard. No other units of measurement are included in this
control.
standard.
4.3 Other related methods for determining the pH of water
1.3 This standard does not purport to address all of the
or aqueous systems are described in Test Methods D1293 and
safety concerns, if any, associated with its use. It is the
E70.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
5. Apparatus
bility of regulatory limitations prior to use.
5.1 pH Meter,
2. Referenced Documents
5.2 Glass and Reference Electrodes.
2.1 ASTM Standards:
NOTE 1—Due to the polarity of electrocoat materials it is desirable to
D1193Specification for Reagent Water
useaseparatesetofelectrodesforeachbathpolarity,cathodicandanodic,
D1293Test Methods for pH of Water
because a bath of opposite polarity poisons the electrodes. A desired
E70Test Method for pH of Aqueous Solutions With the
practice is to rinse the electrodes after each measurement with an
appropriate solvent for the electrocoat material.
Glass Electrode
E180Practice for Determining the Precision of ASTM
5.3 Thermometer, capable of 0.5°C accuracy with a −2 to
Methods for Analysis and Testing of Industrial and Spe-
32°C range.
cialty Chemicals (Withdrawn 2009)
6. Reagents
3. Summary of Test Method
6.1 Reference Standard Solutions, commercial standards of
3.1 Aspecimen of a well-agitated electrocoat bath is placed
pH 4.0, 7.0, and 10.0.
in a stirrer-equipped container and the pH measured with a pH
6.2 Purity of Water—References to water shall be under-
meter and associated glass and reference electrodes.
stood to mean water conforming to Type II of Specification
D1193.
4. Significance and Use
4.1 The pH is the measure of the free hydrogen ion
7. Sampling and Sample Preparation
concentration of a sample, and it indicates whether an electro-
7.1 The sample should be obtained while the electrocoat
coatbathisacidic,neutral,orbasic.SincepHmeasurementsof
bath is under proper circulation so that a uniform material is
obtained. In case of an ultrafiltrate, the material should be
This test method is under the jurisdiction of ASTM Committee D01 on Paint
thoroughly mixed or stirred prior to sampling to assure
and Related Coatings, Materials, andApplicationsand is the direct responsibility of
uniformity.
Subcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.
Current edition approved June 1, 2010. Published June 2010. Originally
7.2 After sampling and prior to removing a test specimen it
approved in 1986. Last previous edition approved in 2005 as D4584-05. DOI:
is mandatory that the sample be shaken or stirred until it is
10.1520/D4584-05R10.
homogeneous and free of any settled material. This is particu-
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
larly important if there is any delay between the sampling of
Standards volume information, refer to the standard’s Document Summary page on
the bath and the preparation of the specimens for the test. The
the ASTM website.
absence of settled material can be ascertained visually (in a
The last approved version of this historical standard is referen
...
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