ASTM D3635-90(1998)

Standard Test Method for Dissolved Copper In Electrical Insulating Oil By Atomic Absorption Spectrophotometry

SCOPE
1.1 This test method covers the determination of copper in new or used electrical insulating oil of petroleum origin by atomic absorption spectrophotometry.  
1.2 The lowest limit of detectability is primarily dependent upon the method of atomization, but also upon the energy source, the fuel and oxidant, and the degree of electrical expansion of the output signal. The lowest detectable concentration is usually considered to be equal to twice the maximum variation of the background. For flame atomization, the lower limit of detectability is generally in the order of 0.1 ppm. For non-flame atomization, the lower limit of detectability is less than 0.01 ppm.  
1.3 The values stated in acceptable metric units are to be regarded as the standard.  
1.4 This standard does not purport to address all of the safety problems, 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. See 5.4 for specific precautionary statements.

General Information

• Status: Historical
• Publication Date: 09-Apr-2001
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.03 - Analytical Tests

Relations

• Replaced By: ASTM D3635-01 - Standard Test Method for Dissolved Copper In Electrical Insulating Oil By Atomic Absorption Spectrophotometry
• Effective Date: 10-Apr-2001

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NOTICE: This standard has either been superseded and replaced by a new version or
withdrawn.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: D 3635 – 90 (Reapproved 1998)
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Copper In Electrical Insulating Oil By Atomic Absorption
1
Spectrophotometry
This standard is issued under the fixed designation D 3635; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 4. Significance and Use
1.1 This test method covers the determination of copper in 4.1 Electrical insulating oil may contain small amounts of
new or used electrical insulating oil by atomic absorption dissolved metals derived either directly from the base oil or
spectrophotometry. from contact with metals during refining or service. When
1.2 The lowest limit of detectability is primarily dependent copper is present, it acts as a catalyst in promoting oxidation of
upon the method of atomization, but also upon the energy the oil. This test method is useful for research and to assess the
source, the fuel and oxidant, and the degree of electrical condition of service-aged oils.
expansion of the output signal. The lowest detectable concen-
5. Apparatus
tration is usually considered to be equal to twice the maximum
variation of the background. For flame atomization, the lower 5.1 Volumetric flasks, 100-mL capacity.
5.2 Burets, 5 and 50-mL capacity.
limit of detectability is generally in the order of 0.1 ppm. For
non-flame atomization, the lower limit of detectability is less 5.3 Atomic Absorption Spectrophotometer —The instru-
ment shall have an atomizer, a spectral energy source, usually
than 0.01 ppm.
1.3 The values stated in acceptable metric units are to be consisting of a copper hollow cathode lamp, a monochromator
capable of isolating the desired line of radiation, an adjustable
regarded as the standard.
1.4 This standard does not purport to address all of the slit, a photomultiplier tube or other photosensitive device as a
light measuring and amplifying device, and a read-out mecha-
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro- nism for indicating the amount of absorbed radiation. Caution:
Proper ventilation must be provided to remove toxic metal
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use. See 5.3 for specific vapors.
5.3.1 Instruments employing flame atomization require a
precautionary statements.
nebulizer assembly, burner head, and suitable pressure and
2. Referenced Documents
flow regulating devices to maintain constant oxidant and fuel
2.1 ASTM Standards: flow for the duration of the tests.
2
D 1193 Specification for Reagent Water 5.3.1.1 Oxidant-Air, cleaned and dried through a suitable
D 2576 Method of Test for Metals in Water and Waste filter to remove oil, water, and other foreign substances.
3
Water by Atomic Absorption Spectrophotometry 5.3.1.2 Acetylene, purified grade.
NOTE 1—Acetylene cylinders should be replaced when the pressure
3. Summary of Test Method
reaches 100 psi to prevent acetone, always present, from entering and
3.1 The sample of oil is diluted with an appropriate organic
damaging the burner head.
solvent and analyzed in an atomic absorption spectrophotom-
4
5.3.1.3 Glass Syringe, 10-mL capacity.
eter. Alternate procedures are provided for instruments em-
5.3.1.4 Platinum Dish, 200-mL capacity minimum.
ploying flame and non-flame atomization. Concentration is
5.3.2 Instruments employing non-flame atomization require
determined by means of calibration curves prepared from
a suitable pressure regulating device to maintain an inert
standard samples.
atmosphere.
5.3.2.1 Argon, commercial grade.
1
This test method is under the jurisdiction of ASTM Committee D-27 on
Electrical Insulating Liquids and Gasesand is the direct responsibility of Subcom-
mittee D27.03on Analytical Tests.
Current edition approved Jan. 26, 1990. Published March 1990. Originally
published as D 3635 – 77. Last previous edition D 3635 – 84.
2 4
Annual Book of ASTM Standards, Vol. 11.01. B-D Multifit syringes with glass Luer tips, available from Becton, Dickenson
3
Discontinued; see 1980 Annual Book of ASTM Standards, Part 31. and Co., Rutherford, NJ have been found satisfactory for this method.
1

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D 3635
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5.3.2.2 Carbon Rod Analyzer and Carbon Tube Atomizer. 8.2.2 Dilute the 10 μg/mL Cu solution with new oil so as to
6
5.3.2.3 Strip Chart Recorder (if permanent record is re- obtain four standards containing add
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