ASTM D1934-95(2012)
(Test Method)Standard Test Method for Oxidative Aging of Electrical Insulating Petroleum Oils by Open-Beaker Method
Standard Test Method for Oxidative Aging of Electrical Insulating Petroleum Oils by Open-Beaker Method
SIGNIFICANCE AND USE
Open-beaker oxidative aging methods have been used for many years in laboratories of oil companies, electrical equipment manufacturers, and electric utility companies interested in the stability of electrical insulating oils under oxidative conditions. They are particularly useful as a check on the continuity of production and shipment of insulating oils. They are also useful as process and product checks for applicable type oils.
Specification limits for oils subjected to open-beaker oxidative aging by this method are established by agreement between individual producers and consumers of applicable type oils. These properties of the oil involved in specification limits for aging stability may be measured after the oxidative aging (and sometimes before aging) by appropriate test methods such as Test Method D924, Test Method D1169, and Test Method D664.
SCOPE
1.1 This test method covers two procedures for subjecting electrical insulating oils to oxidative aging:
1.1.1 Procedure A, without a metal catalyst, and
1.1.2 Procedure B, with a metal catalyst.
1.2 This test method is applicable to oils used as impregnating or pressure media in electrical power transmission cables if less than 10 % of the oil evaporates during the aging procedures. It applies and is generally useful primarily in the evaluation and quality control of unused oils, either inhibited or uninhibited.
1.3 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.
1.4 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.
General Information
Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D1934 − 95 (Reapproved 2012)
Standard Test Method for
Oxidative Aging of Electrical Insulating Petroleum Oils by
Open-Beaker Method
This standard is issued under the fixed designation D1934; 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 E177 Practice for Use of the Terms Precision and Bias in
ASTM Test Methods
1.1 This test method covers two procedures for subjecting
electrical insulating oils to oxidative aging:
3. Terminology
1.1.1 Procedure A, without a metal catalyst, and
3.1 Definitions of Terms Specific to This Standard:
1.1.2 Procedure B, with a metal catalyst.
3.1.1 metal catalyst—any metal (for example, copper) that
1.2 This test method is applicable to oils used as impreg-
eitherincreasestherateofoxidationoftheoilorreactswiththe
nating or pressure media in electrical power transmission
oxidation products to increase oil dielectric loss.
cables if less than 10 % of the oil evaporates during the aging
3.1.2 oxidative aging—exposure of oil to oxygen under
procedures. It applies and is generally useful primarily in the
certain specified conditions.
evaluation and quality control of unused oils, either inhibited
or uninhibited.
4. Summary of Test Method
1.3 The values stated in SI units are to be regarded as
4.1 A300 mLvolume of oil, contained in 400 mLbeaker is
standard. The values given in parentheses are for information
aged for 96 h in a circulating-air oven controlled at 115°C,
only.
either with or without the presence of catalyst.
1.4 This standard does not purport to address all of the
5. Significance and Use
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5.1 Open-beaker oxidative aging methods have been used
priate safety and health practices and determine the applica-
for many years in laboratories of oil companies, electrical
bility of regulatory limitations prior to use.
equipment manufacturers, and electric utility companies inter-
estedinthestabilityofelectricalinsulatingoilsunderoxidative
2. Referenced Documents
conditions. They are particularly useful as a check on the
2.1 ASTM Standards:
continuity of production and shipment of insulating oils. They
D664 Test Method for Acid Number of Petroleum Products
are also useful as process and product checks for applicable
by Potentiometric Titration
type oils.
D923 Practices for Sampling Electrical Insulating Liquids
5.2 Specification limits for oils subjected to open-beaker
D924 Test Method for Dissipation Factor (or Power Factor)
oxidative aging by this method are established by agreement
and Relative Permittivity (Dielectric Constant) of Electri-
between individual producers and consumers of applicable
cal Insulating Liquids
type oils. These properties of the oil involved in specification
D1169 Test Method for Specific Resistance (Resistivity) of
limits for aging stability may be measured after the oxidative
Electrical Insulating Liquids
aging (and sometimes before aging) by appropriate test meth-
E145 Specification for Gravity-Convection and Forced-
ods such as Test Method D924, Test Method D1169, and Test
Ventilation Ovens
Method D664.
6. Apparatus
This test method is under the jurisdiction of ASTM Committee D27 on
Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-
6.1 Oven, electrically heated, thermostatically controlled,
mittee D27.06 on Chemical Test.
capable of maintaining a constant temperature of 115 6 1°C
Current edition approved Feb. 1, 2012. Published February 2012. Originally
(239 6 2°F). Use an oven with a testing chamber large enough
approved in 1962. Last previous edition approved in 2005 as D1934 – 95 (2005).
DOI: 10.1520/D1934-95R12.
to test the anticipated number of test specimens at one time.A
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
uniformity of temperature within 61 % of the differential
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
between oven and ambient temperatures is required. (See Note
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 1.) Circulate air in the chamber with a low velocity fan during
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D1934 − 95 (2012)
the aging period. The volume and condition of the circulated 7.5 Metal Catalyst with 15 cm of clean surface available
air is not considered to be critical. It is recommended that the for exposure to the oil for use in Procedure B. If the metal
oven provide several air changes per hour, and that vapors and catalyst is copper wire, it is convenient to wind an appropriate
fumes be removed if present. length into a loose hank which is then cleaned to remove oil,
oxide, and the other extraneous matter. The metal catalyst may
NOTE 1—Refer to Specification E145 for the measurement of the
also be used in the form of strips, but the strips require special
temperature uniformity of the oven.
attention to maintain the desired amount of exposed surface.
6.1.1 Procedure A—For test specimens aged in the absence
One good method of cleaning copper hanks is to immerse the
of a metal catalyst the choice of a suitable oven design is not
hank for 30 s in a 10 % solution of hydrochloric acid (HCl),
critical. Either fixed- or rotating-shelf stage ovens of satisfac-
afterwhichthehankisrinsedthreetimesindistilledwaterthen
tory thermal quality may be used, although a rotating-shelf
in acetone and air dried. The cleaned hank should be handled
oven is preferred. If a fixed-shelf oven is used, it is recom-
with clean tongs.
mended that test specimen positions within the oven be
changed periodically (for example, at daily intervals) to mini-
8. Procedure A—Aging Without a Metal Catalyst
mize the effects of any temperature differentials that may exist.
8.1 Obtain the oil sample in accordance with Practices
6.1.2 Procedure B—When a metal catalyst, such as copper,
is used, the rate of oxidation usually is increased, and the D923.
procedure becomes sensitive to movement of the oil past the
8.2 Adjust the oven temperature to 115 6 1°C.
metal surface. An aging oven equipped with a slowly rotating
8.3 Pour without preheating 300 mLof the test specimen to
shelf has been adopted for uniformity when a metal catalyst is
be tested into a clean dry 400-mL beaker. Oil depth in the
used. Other oven designs having satisfactory thermal quality
beaker will be approximately 75 mm. Measure the mass of the
and a rotating shelf may be used.
...
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