ASTM D2502-04(2009)
(Test Method)Standard Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils From Viscosity Measurements
Standard Test Method for Estimation of Molecular Weight (Relative Molecular Mass) of Petroleum Oils From Viscosity Measurements
SIGNIFICANCE AND USE
This test method provides a means of calculating the mean relative molecular mass of petroleum oils from another physical measurement.
Mean relative molecular mass is a fundamental physical constant that can be used in conjunction with other physical properties to characterize hydrocarbon mixtures.
SCOPE
1.1 This test method covers the estimation of the mean relative molecular mass of petroleum oils from kinematic viscosity measurements at 100 and 210°F (37.78 and 98.89°C). It is applicable to samples with mean relative molecular masses in the range from 250 to 700 and is intended for use with average petroleum fractions. It should not be applied indiscriminately to oils that represent extremes of composition or possess an exceptionally narrow mean relative molecular mass range.
1.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.3 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
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
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Designation: D2502 − 04(Reapproved 2009)
Standard Test Method for
Estimation of Mean Relative Molecular Mass of Petroleum
1
Oils from Viscosity Measurements
This standard is issued under the fixed designation D2502; 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 3. Summary of Test Method
1.1 This test method covers the estimation of the mean
3.1 The kinematic viscosity of the oil is determined at 100
relative molecular mass of petroleum oils from kinematic
and 210°F (37.78 and 98.89°C). A function “H” of the 100°F
viscosity measurements at 100 and 210°F (37.78 and
viscosity is established by reference to a tabulation of H
2
98.89°C). It is applicable to samples with mean relative
function versus 100°F viscosity. The H value and the 210°F
molecular masses in the range from 250 to 700 and is intended
viscosity are then used to estimate the mean relative molecular
for use with average petroleum fractions. It should not be
mass from a correlation chart.
applied indiscriminately to oils that represent extremes of
composition or possess an exceptionally narrow mean relative
4. Significance and Use
molecular mass range.
4.1 This test method provides a means of calculating the
1.2 The values stated in inch-pound units are to be regarded
mean relative molecular mass of petroleum oils from another
as standard. The values given in parentheses are mathematical
physical measurement.
conversions to SI units that are provided for information only
4.2 Mean relative molecular mass is a fundamental physical
and are not considered standard.
constant that can be used in conjunction with other physical
1.3 This standard does not purport to address all of the
properties to characterize hydrocarbon mixtures.
safety concerns, if any, associated with its use. It is the
responsibility of the user of this standard to establish appro-
5. Procedure
priate safety and health practices and determine the applica-
bility of regulatory limitations prior to use.
5.1 Determine the kinematic viscosity of the oil at 100 and
210°F (37.78 and 98.89°C) as described in Test Method D445.
2. Referenced Documents
5.2 Look in Table 1 for 100°F (37.78°C) viscosity and read
3
2.1 ASTM Standards:
the value of H that corresponds to the measured viscosity.
D445 Test Method for Kinematic Viscosity of Transparent
Linear interpolation between adjacent columns may be re-
and Opaque Liquids (and Calculation of Dynamic Viscos-
quired.
ity)
5.3 Read the viscosity–mean relative molecular mass chart
2.2 ASTM Adjuncts:
for H and 210°F (98.89°C) viscosity. A simplified version of
Mean Relative Molecular Mass of Petroleum Oils from
thischartisshowninFig.1forillustrationpurposesonly(Note
4
Viscosity Measurements
1). Interpolate where necessary between adjacent lines of
210°F viscosity. After locating the point corresponding to the
value of H (ordinate) and the 210°F viscosity (superimposed
1
This test method is under the jurisdiction of ASTM Committee D02 on
lines), read the mean relative molecular mass along the
Petroleum Products and Lubricants and is the direct responsibility of Subcommittee
abscissa.
D02.04.0K on Correlative Methods.
Current edition approved Oct. 1, 2009. Published November 2009. Originally
Example:
approved in 1966. Last previous edition approved in 2004 as D2502–04. DOI:
Measured viscosity, cSt:
10.1520/D2502-04R09.
100°F (37.78°C) = 179
2
Hirschler, A. E., Journal of the Institute of Petroleum, JIPEA, Vol 32, 1946, p.
210°F (98.89°C) = 9.72
133.
Look in Table 1 for 179 and read the corresponding value H
3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM = 461.
Standards volume information, refer to the standard’s Document Summary page on
Using H = 461 and 210°F viscosity = 9.72 in conjunction
the ASTM website.
4
with chart gives mean relative molecular mass = 360 (see Fig.
Available from ASTM International Headquarters. Order Adjunct No.
ADJD2502. 1).
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
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D2502 − 04 (2009)
TABLE 1 Tabulation ofHFunction
Kinematic
Viscosity,
H
cSt at 100°F
(37.78°C)
0 0.2 0.4 0.6 0.8
2 −178 −151 −126 −104 −85
3 −67 −52 −38 −25 −13
4 −1 9 19 28 36
544 52 59 66 73
6 79 85 90 96 101
7 106 111 116 120 124
8 128 132 136 140 144
9 147 151 154 157 160
10 163 166 169 172 175
11 178 180 183 185 188
12 190 192 195 197 199
13 201 203 206 208 210
14 211 213 215 217 219
15 221 222 224 226 227
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...
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