ASTM D1534-95(2008)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D1534 − 95 (Reapproved 2008)
Standard Test Method for
Approximate Acidity in Electrical Insulating Liquids by
Color-Indicator Titration
This standard is issued under the fixed designation D1534; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope bottom of the container when testing mineral oils, or at the top
when testing askarels, determines whether the acidity is less
1.1 This test method describes the determination of the
than or greater than the arbitrary value chosen.
approximate total acid value of used electrical insulating
liquidshavingviscositieslessthan24cStat40°C.Itisasimple 3.2 To determine the approximate total acidity, the proce-
procedure that can be applied in the field. Where a quantitative dure is the same as described in 3.1 except that the potassium
neutralization value is required, use Test Method D664 or Test hydroxide solution is added in small increments until the color
Method D974. These test methods should be applied in the of the aqueous layer, after shaking and settling, is a faint pink.
laboratory. The volume of standard potassium hydroxide solution used
determines the approximate total acid value.
1.2 The values stated in SI units are to be regarded as
standard. No other units of measurement are included in this
4. Significance and Use
standard.
4.1 The approximate acidity of used electrical insulating
1.3 This standard does not purport to address all of the
oils is an estimate of the total acid value of the oil. As acid
safety concerns, if any, associated with its use. It is the
values increase, oil quality decreases. This is usually due to
responsibility of the user of this standard to establish appro-
oxidation of the oil while in service. In general, acidic
priate safety and health practices and determine the applica-
by-products produce increased dielectric loss, increased
bility of regulatory limitations prior to use.
corrosivity, and may cause thermal difficulties attributable to
insoluble components called “sludge.” This test method is
2. Referenced Documents
adapted to a specific volume of oil; total acid values of 0.05 to
2.1 ASTM Standards:
0.5mgofpotassiumhydroxidepergramofoilisarangewhich
D664 Test Method for Acid Number of Petroleum Products
is functionally significant.
by Potentiometric Titration
D974 Test Method for Acid and Base Number by Color-
5. Apparatus
Indicator Titration
5.1 Graduated Cylinder, 50 mL, stoppered.
D1193 Specification for Reagent Water
5.2 Medicine Dropper, calibrated at 1-mL intervals.
3. Summary of Test Method
5.3 Calibrated Pipet, 1-mL capacity, calibrated to deliver
3.1 To determine whether the acidity is greater or less than
0.05-mL increments.
a specified arbitrary value, a fixed volume of liquid to be tested
is added to a graduated cylinder, together with a small amount
6. Reagents and Materials
of indicator (phenolphthalein) and the appropriate quantity of
6.1 Purity of Reagents—Use reagent grade chemicals in all
standard potassium hydroxide solution. The mixture is shaken
tests. Unless otherwise indicated, it is intended that all reagents
and allowed to separate. The color of the aqueous layer at the
shall conform to the specifications of the Committee on
Analytical Reagents of theAmerican Chemical Society, where
This test method is under the jurisdiction of ASTM Committee D27 on
such specifications are available. Other grades may be used,
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
mittee D27.06 on Chemical Test.
Current edition approved May 1, 2008. Published June 2008. Originally
´1
approved in 1958. Last previous edition approved in 2002 as D1534– 95(2002) . Reagent Chemicals, American Chemical Society Specifications, American
DOI: 10.1520/D1534-95R08. Chemical Society, Washington, DC. For suggestions on the testing of reagents not
For referenced ASTM standards, visit the ASTM website, www.astm.org, or listed by the American Chemical Society, see Analar Standards for Laboratory
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
Standards volume information, refer to the standard’s Document Summary page on and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
the ASTM website. MD.
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D1534 − 95 (2008)
provided it is first ascertained that the reagent is of sufficiently 7.3 To determine the approximate total acidity, add KOH
high purity to permit its use without lessening the accuracy of solution in increments of 0.5 mLuntil the color of the aqueous
the determination. layer, after shaking and settling, is a pale pink.
6.2 Purity of Water—Unless otherwise indicated, re
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