ASTM D6181-03

Standard Test Method for Measurement of Turbidity in Mineral Insulating Oil of Petroleum Origin (Withdrawn 2012)

SIGNIFICANCE AND USE
This test method uses a ratio turbidimetric optical system to measure the turbidity of insulating oils relative to turbidity standards. Cloudiness or turbidity is attributed to matter whose diameter is approximately 20 % of the wavelength of the incident light. Increasing turbidity signifies increasing transformer fluid contamination, either from external sources or internal chemical reactions (such as oxidation) that produce fine particulate matter. Other turbidity sources, such as water droplets or gas bubbles, are not of interest in this evaluation of insulating oils. The elimination of these interferences is described in 6.2 and 6.6. This test method quantifies changes which may not be apparent to the unaided human eye.
SCOPE
1.1 This test method covers the laboratory procedure that ascertains the quantity of suspensions in insulating oils of petroleum origin using a nephelometric measurement technique to determine the fluid's turbidity. This test method is designed to reveal changes that may occur to these oils.
1.2 This test method is applicable for turbidities in the range of 0.1 to 500 Nephelometric Turbidity Units (NTU).
1.3 The values stated in SI units are to be regarded as the 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.
WITHDRAWN RATIONALE
This test method covers the laboratory procedure that ascertains the quantity of suspensions in insulating oils of petroleum origin using a nephelometric measurement technique to determine the fluid's turbidity. This test method is designed to reveal changes that may occur to these oils.
Formerly under the jurisdiction of Committee D27 on Electrical Insulating Liquids and Gases, this test method was withdrawn in January 2012 in accordance with section 10.5.3.1 of the Regulations Governing ASTM Technical Committees, which requires that standards shall be updated by the end of the eighth year since the last approval date.

General Information

• Status: Withdrawn
• Publication Date: 30-Sep-2003
• Withdrawal Date: 10-Jan-2012
• ICS: 29.040.10 - Insulating oils
• Technical Committee: D27 - Electrical Insulating Liquids and Gases
• Drafting Committee: D27.07 - Physical Test

Relations

• Replaces: ASTM D6181-97 - Standard Test Method for Measurement of Turbidity in Mineral Insulating Oil of Petroleum Origin
• Effective Date: 01-Oct-2003

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:D6181–03
Standard Test Method for
Measurement of Turbidity in Mineral Insulating Oil of
1
Petroleum Origin
This standard is issued under the fixed designation D6181; 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 the laboratory procedure that
ascertains the quantity of suspensions in insulating oils of
3. Terminology
petroleum origin using a nephelometric measurement tech-
3.1 Description of Terms Specific to This Standard:
nique to determine the fluid’s turbidity. This test method is
3.1.1 nephelometric turbidity unit (NTU), n—intensity of
designed to reveal changes that may occur to these oils.
light scattered by a known aqueous suspension of formazine.
1.2 Thistestmethodisapplicableforturbiditiesintherange
One NTU is the turbidity of a formazine solution produced by
of 0.1 to 500 Nephelometric Turbidity Units (NTU).
mixing 12.5 µg of hydrazine su1fate and 1.25 µg of hexa-
1.3 The values stated in SI units are to be regarded as the
methylenetetramine in 1 mL of turbidity-free water. See
standard. The values given in parentheses are for information
Appendix X1 for preparation instructions.
only.
3.1.2 turbidity, n—the reduction of transparency due to the
1.4 This standard does not purport to address all of the
presence of particulate matter.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
4. Summary of Test Method
priate safety and health practices and determine the applica-
4.1 The turbidity is determined by a calibrated, ratio turbi-
bility of regulatory limitations prior to use.
dimeter, which measures scattered light at 0.5 p rad (90°) or
0.5 and 1.5 p rad (90 and 270°) angles to the incident beam.
2. Referenced Documents
2
These instruments cannot be calibrated accurately in terms of
2.1 ASTM Standards:
absolute turbidity except in the case of fluids having uniform-
D923 Practices for Sampling Electrical Insulating Liquids
size particles that are less than approximately one fifth of the
D1533 Test Method for Water in Insulating Liquids by
wavelengthoftheincidentlight.Standardshavebeenprepared
Coulometric Karl Fischer Titration
by thoroughly mixing suitable amounts of finely divided
D1698 Test Method for Sediments and Soluble Sludge in
titanium dioxide into partially polymerized polystyrene.Alter-
Service-Aged Insulating Oils
3 natively, suspension of formazine has been used as a turbidity
D1889 Test Method for Turbidity of Water
standard, formed by reacting hydrazine sulfate and hexameth-
D4652 Specification for Silicone Fluid Used for Electrical
4
ylenetetramine under carefully controlled conditions. Cali-
Insulation
brated commercial standards in sealed tubes also are available.
D5180 Test Method for Quantitative Test for Turbidity in
3 4.2 The test specimen is placed in the cell and its turbidity
Clear Liquids
is measured. The turbidimeter measures the light scattered by
suspended solids dispersed within the test specimen.Accuracy
and sensitivity of the method is ensured by measuring the
1
This test method is under the jurisdiction of ASTM Committee D27 on
turbidity at a wavelength of light where there is little or no
Electrical Insulating Liquids and Gases and is the direct responsibility of Subcom-
absorption of the light by the test specimen. Use of a narrow
mittee D27.07 on Physical Test.
bandwidth of light reduces interference that may be inherent to
Current edition approved Oct. 1, 2003. Published December 2003. Originally
approved in 1997. Last previous edition approved in 1997 as D6181-97. DOI:
oxidized insulating oils. The narrow bandwidth is achieved
10.1520/D6181-03.
through the use of an optical filter to provide light at 600 nm
2
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
with a 40 nm bandwidth.
contactASTM Customer Service at [e-mail]. ForAnnual Book ofASTM
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website.
3 4
Withdrawn. The last approved version of this historical standard is referenced For information, see Chevalier, P., “Formazine Standard for Turbidity,”
on www.astm.org. Brasserie, Vol 152, 1959, pp. 132–133.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
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D6181–03
4.3 This test method is recommended only for mineral
Peak Transmittance 50 %
insulating oils and is not inten
...