ASTM D4584-86(1999)

Standard Test Method for Measuring Apparent pH of Electrocoat Baths

SCOPE
1.1 This test method covers the measurement of the free hydrogen ion concentration of electrocoat baths and their ultrafiltrates.  
1.2 This standard does not purport to address the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine applicability of regulatory limitations prior to use.

General Information

• Status: Historical
• Publication Date: 09-May-1999
• ICS: 25.220.40 - Metallic coatings
• Technical Committee: D01 - Paint and Related Coatings, Materials, and Applications
• Drafting Committee: D01.21 - Chemical Analysis of Paints and Paint Materials

Relations

• Replaced By: ASTM D4584-05 - Standard Test Method for Measuring Apparent pH of Electrocoat Baths
• Effective Date: 01-Jan-2005
• Referred By: ASTM D1978-91(2018) - Standard Guide for Analysis of Electrocoat Bath Samples
• Effective Date: 10-May-1999

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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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:D4584–86(Reapproved1999)
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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4.3 Other related methods for determining the pH of water
or aqueous systems are described in Test Methods D1293 and
1.1 This test method covers the measurement of the free
E70.
hydrogen ion concentration of electrocoat baths and their
ultrafiltrates.
5. Apparatus
1.2 This standard does not purport to address all of the
5.1 pH Meter,
safety concerns, if any, associated with its use. It is the
5.2 Glass and Reference Electrodes.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
NOTE 1—Due to the polarity of electrocoat materials it is desirable to
bility of regulatory limitations prior to use. useaseparatesetofelectrodesforeachbathpolarity,cathodicandanodic,
because a bath of opposite polarity poisons the electrodes. A desired
2. Referenced Documents
practice is to rinse the electrodes after each measurement with an
appropriate solvent for the electrocoat material.
2.1 ASTM Standards:
D1193 Specification for Reagent Water 5.3 Thermometer, capable of 0.5°C accuracy with a−2 to
32°C range.
D1293 Test Methods for pH of Water
E70 Test Method for pH of Aqueous Solutions with the
3 6. Reagents
Glass Electrode
6.1 Reference Standard Solutions, commercial standards of
E 180 Practice for Determining the Precision Data of
pH 4.0, 7.0, and 10.0.
ASTM Methods for Analysis and Testing of Industrial
6.2 Purity of Water—References to water shall be under-
Chemicals
stood to mean water conforming to Type II of Specification
3. Summary of Test Method
D1193.
3.1 Aspecimen of a well-agitated electrocoat bath is placed
7. Sampling and Sample Preparation
in a stirrer-equipped container and the pH measured with a pH
7.1 The sample should be obtained while the electrocoat
meter and associated glass and reference electrodes.
bath is under proper circulation so that a uniform material is
4. Significance and Use
obtained. In case of an ultrafiltrate, the material should be
thoroughly mixed or stirred prior to sampling to assure
4.1 The pH is the measure of the free hydrogen ion
concentration of a sample, and it indicates whether an electro- uniformity.
7.2 After sampling and prior to removing a test specimen it
coatbathisacidic,neutral,orbasic.SincepHmeasurementsof
good precision are made in aqueous solutions, it is suggested is mandatory that the sample be shaken or stirred until it is
homogeneous and free of any settled material. This is particu-
that the pH measurements of electrocoat baths are only
semi-quantitative, and therefore such measurements should be larly important if there is any delay between the sampling of
the bath and the preparation of the specimens for the test. The
referred to as apparent pH measurements.
4.2 The pH of electrocoat paints is used for research, absence of settled material can be ascertained visually (in a
transparent container) or by inserting a spatula, scraping the
production, and quality control or electrocoat bath process
control. bottom of the container to make sure that there is no settled
matter. Shake or stir the samples until specimens are taken for
measurement; this point is very important.
This test method is under the jurisdiction of ASTM Committee D-1 on Paint
and Related
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