ASTM D3635-13(2021)

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

SIGNIFICANCE AND USE
4.1 Electrical insulating oil may contain small amounts of dissolved metals derived either directly from the base oil or from contact with metals during refining or service. When copper is present, it acts as a catalyst in promoting oxidation of the oil. This test method is useful for research for new oils and to assess the condition of service-aged oils. Consideration should be given to the limits of detection outlined in the scope.
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 or 0.1 mg/kg. For non-flame atomization, the lower limit of detectability is less than 0.01 ppm.  
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.  
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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

General Information

• Status: Published
• Publication Date: 30-Nov-2021
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.03 - Analytical Tests

Standards Content (Sample)

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: D3635 − 13 (Reapproved 2021)
Standard Test Method for
Dissolved Copper In Electrical Insulating Oil By Atomic
1
Absorption Spectrophotometry
This standard is issued under the fixed designation D3635; 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 D3487 Specification for Mineral Insulating Oil Used in
Electrical Apparatus
1.1 This test method covers the determination of copper in
D5222 Specification for High Fire-Point Mineral Electrical
new or used electrical insulating oil of petroleum origin by
Insulating Oils
atomic absorption spectrophotometry.
1.2 The lowest limit of detectability is primarily dependent
3. Summary of Test Method
upon the method of atomization, but also upon the energy
3.1 The test specimen of oil is filtered and diluted with an
source, the fuel and oxidant, and the degree of electrical
appropriate organic solvent and analyzed in an atomic absorp-
expansion of the output signal. The lowest detectable concen-
tion spectrophotometer. Alternate procedures are provided for
tration is usually considered to be equal to twice the maximum
instruments employing flame and non-flame atomization. Con-
variation of the background. For flame atomization, the lower
centration is determined by means of calibration curves pre-
limit of detectability is generally in the order of 0.1 ppm or 0.1
pared from standard samples.
mg/kg. For non-flame atomization, the lower limit of detect-
ability is less than 0.01 ppm.
4. Significance and Use
1.3 The values stated in SI units are to be regarded as
4.1 Electrical insulating oil may contain small amounts of
standard. No other units of measurement are included in this
dissolved metals derived either directly from the base oil or
standard.
from contact with metals during refining or service. When
1.4 This standard does not purport to address all of the
copper is present, it acts as a catalyst in promoting oxidation of
safety concerns, if any, associated with its use. It is the
the oil. This test method is useful for research for new oils and
responsibility of the user of this standard to establish appro-
to assess the condition of service-aged oils. Consideration
priate safety, health, and environmental practices and deter-
should be given to the limits of detection outlined in the scope.
mine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accor-
5. Apparatus
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
5.1 Volumetric flasks, 100-mL capacity.
Development of International Standards, Guides and Recom-
5.2 Membrane filter, 0.45 µm.
mendations issued by the World Trade Organization Technical
Barriers to Trade (TBT) Committee. 5.3 Burets, 5-mL and 50-mL capacity.
5.4 AtomicAbsorption Spectrophotometer —Theinstrument
2. Referenced Documents
shall have an atomizer, a spectral energy source, usually
2
2.1 ASTM Standards:
consisting of a copper hollow cathode lamp, a monochromator
D1193 Specification for Reagent Water
capable of isolating the desired line of radiation, an adjustable
slit, a photomultiplier tube or other photosensitive device as a
light measuring and amplifying device, and a read-out mecha-
1
nism for indicating the amount of absorbed radiation.
This test method is under the jurisdiction of ASTM Committee D27 on
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
Warning—Proper ventilation must be provided to remove
mittee D27.03 on Analytical Tests.
toxic metal vapors.
Current edition approved Dec. 1, 2021. Published January 2022. Originally
5.4.1 Instruments employing flame atomization require a
approved in 1977. Last previous edition approved in 2013 as D3635 – 13. DOI:
10.1520/D3635-13R21.
nebulizer assembly, burner head, and suitable pressure and
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
flow regulating devices to maintain constant oxidant and fuel
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
flow for the duration of the tests.
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. 5.4.1.1 Glass Syringe, 10-mL capacity.
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