ASTM D5002-99(2010)
(Test Method)Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
Standard Test Method for Density and Relative Density of Crude Oils by Digital Density Analyzer
SIGNIFICANCE AND USE
Density is a fundamental physical property that can be used in conjunction with other properties to characterize the quality of crude oils.
The density or relative density of crude oils is used for the conversion of measured volumes to volumes at the standard temperatures of 15°C or 60°F and for the conversion of crude mass measurements into volume units.
The application of the density result obtained from this test method, for fiscal or custody transfer accounting calculations, can require measurements of the water and sediment contents obtained on similar specimens of the crude oil parcel.
SCOPE
1.1 This test method covers the determination of the density or relative density of crude oils that can be handled in a normal fashion as liquids at test temperatures between 15 and 35°C. This test method applies to crude oils with high vapor pressures provided appropriate precautions are taken to prevent vapor loss during transfer of the sample to the density analyzer.
1.2 This test method was evaluated in round robin testing using crude oils in the 0.75 to 0.95 g/mL range. Lighter crude oil can require special handling to prevent vapor losses. Heavier crudes can require measurements at higher temperatures to eliminate air bubbles in the sample.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. The accepted units of measurement of density are grams per millilitre and kilograms per cubic metre.
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. Specific warning statements are given in 7.4, 7.5, and 7.6.
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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NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.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: D5002 − 99(Reapproved 2010)
Standard Test Method for
Density and Relative Density of Crude Oils by Digital
Density Analyzer
This standard is issued under the fixed designation D5002; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope cific Gravity) of Liquids by Bingham Pycnometer
D1250Guide for Use of the Petroleum MeasurementTables
1.1 Thistestmethodcoversthedeterminationofthedensity
D4052Test Method for Density, Relative Density, and API
orrelativedensityofcrudeoilsthatcanbehandledinanormal
Gravity of Liquids by Digital Density Meter
fashion as liquids at test temperatures between 15 and 35°C.
D4057Practice for Manual Sampling of Petroleum and
Thistestmethodappliestocrudeoilswithhighvaporpressures
Petroleum Products
provided appropriate precautions are taken to prevent vapor
D4177Practice for Automatic Sampling of Petroleum and
loss during transfer of the sample to the density analyzer.
Petroleum Products
1.2 This test method was evaluated in round robin testing
D4377TestMethodforWaterinCrudeOilsbyPotentiomet-
using crude oils in the 0.75 to 0.95 g/mL range. Lighter crude
ric Karl Fischer Titration
oil can require special handling to prevent vapor losses.
Heavier crudes can require measurements at higher tempera-
3. Terminology
tures to eliminate air bubbles in the sample.
3.1 Definitions:
1.3 The values stated in SI units are to be regarded as
3.1.1 density—mass per unit volume at a specified tempera-
standard. No other units of measurement are included in this
ture.
standard. The accepted units of measurement of density are
grams per millilitre and kilograms per cubic metre.
3.1.2 relative density—the ratio of the density of a material
1.4 This standard does not purport to address all of the
at a stated temperature to the density of water at a stated
safety concerns, if any, associated with its use. It is the
temperature.
responsibility of the user of this standard to establish appro-
priate safety and health practices and determine the applica-
4. Summary of Test Method
bility of regulatory limitations prior to use. Specific warning
4.1 Approximately0.7mLofcrudeoilsampleisintroduced
statements are given in 7.4, 7.5, and 7.6.
into an oscillating sample tube and the change in oscillating
frequency caused by the change in the mass of the tube is used
2. Referenced Documents
2 inconjunctionwithcalibrationdatatodeterminethedensityof
2.1 ASTM Standards:
the sample.
D941Test Method for Density and Relative Density (Spe-
cific Gravity) of Liquids by Lipkin Bicapillary Pycnom-
3 5. Significance and Use
eter (Withdrawn 1993)
D1193Specification for Reagent Water
5.1 Density is a fundamental physical property that can be
D1217Test Method for Density and Relative Density (Spe-
used in conjunction with other properties to characterize the
quality of crude oils.
This test method is under the jurisdiction of ASTM Committee D02 on 5.2 The density or relative density of crude oils is used for
PetroleumProductsandLubricantsandisthedirectresponsibilityofSubcommittee
theconversionofmeasuredvolumestovolumesatthestandard
D02.04.0D on Physical and Chemical Methods.
temperatures of 15°C or 60°F and for the conversion of crude
Current edition approved Sept. 15, 2010. Published November 2010. Originally
mass measurements into volume units.
approved in 1989. Last previous edition approved in 2005 as D5002–99(2005).
DOI: 10.1520/D5002-99R10.
2 5.3 The application of the density result obtained from this
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
test method, for fiscal or custody transfer accounting
Standards volume information, refer to the standard’s Document Summary page on
calculations, can require measurements of the water and
the ASTM website.
3 sediment contents obtained on similar specimens of the crude
The last approved version of this historical standard is referenced on
www.astm.org. oil parcel.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5002 − 99(Reapproved 2010)
6. Apparatus
6.1 Digital Density Analyzer—Adigital analyzer consisting
of a U-shaped, oscillating sample tube and a system for
D5002 − 99 (2010)
electronic excitation, frequency counting, and display. The 8. Sampling, Test Specimens, and Test Units
analyzer must accommodate the accurate measurement of the
8.1 Samplingisdefinedasallthestepsrequiredtoobtainan
sample temperature during measurement or must control the
aliquotofthecontentsofanypipe,tankorothersystem,andto
sampletemperatureasdescribedin6.2and6.5.Theinstrument
place the sample into the laboratory test container. The
shall be capable of meeting the precision requirements de-
laboratory test container and sample volume shall be of
scribed in Test Method D4052.
sufficient dimensions to allow mixing as described in 8.3.1.
6.2 Circulating Constant-Temperature Bath, capable of Mixing is required to obtain a homogeneous sample for
maintaining the temperature of the circulating liquid constant analysis.
to 60.05°C in the desired range. Temperature control can be
8.2 Laboratory Sample—Use only representative samples
maintained as part of the density analyzer instrument package.
obtained as specified in Practices D4057 or D4177 for this test
6.3 Syringes, at least 2 mL in volume with a tip or an method.
adapter tip that will fit the inlet of the density analyzer.
8.3 Test Specimen—Thealiquotofsampleobtainedfromthe
6.4 Flow-Through or Pressure Adapter, for use as an alter- laboratorysampleanddeliveredtothedensityanalyzersample
native means of introducing the sample into the density meter. tube. The test specimen is obtained as follows:
8.3.1 Mix the sample of crude oil to homogenize any
6.5 Thermometer, calibrated and graduated to 0.1°C, and a
sediment and water present. The mixing may be accomplished
thermometer holder that can be attached to the instrument for
asdescribedinPracticeD4177orTestMethodD4377.Mixing
setting and observing the test temperature. In calibrating the
at room temperature in an open container can result in the loss
thermometer, the ice point and bore corrections should be
of light ends, so mixing in closed, pressurized containers or at
estimated to the nearest 0.05°C. Precise setting and control of
sub-ambient temperatures is recommended.
the test temperature in the sample tube is extremely important.
8.3.2 Draw the test specimen from a properly mixed labo-
Anerrorof0.1°Ccanresultinachangeindensityofoneinthe
ratorysampleusinganappropriatesyringe.Alternatively,ifthe
fourth significant figure.
proper density analyzer attachments and connecting tubes are
used then the test specimen can be delivered directly to the
7. Reagents and Materials
analyzer’s sample tube from the mixing container.
7.1 Purity of Reagents—Reagent grade chemicals shall be
used in all tests. Unless otherwise indicated it is intended that
9. Preparation of Apparatus
all reagents shall conform to the specifications of the Commit-
9.1 Set up the density analyzer and constant temperature
tee onAnalytical Reagents of theAmerican Chemical Society,
bath following the manufacturer’s instructions.Adjust the bath
where such specifications are available. Other grades may be
orinternaltemperaturecontrolsothatthedesiredtesttempera-
used, provided it is first ascertained that the reagent is of
ture is established and maintained in the sample compartment
sufficiently high purity to permit its use without lessening the
of the analyzer. Calibrate the instrument at the same tempera-
accuracy of the determination.
ture at which the density of the sample is to be measured.
7.2 Purity of Water—Unless otherwise indicated, references
to water shall be understood to mean reagent water as defined
10. Calibration of Apparatus
by Type II of Specification D1193.
10.1 Calibrate the instrument when first setting up and
7.3 Water, redistilled, freshly boiled and cooled reagent
whenever the test temperature is changed. Thereafter, conduct
water for use as a primary calibration standard.
calibration checks at least weekly during routine operation or
7.4 Acetone, for flushing and drying the sample tube. more frequently as may be dictated by the nature of the crude
(Warning—Extremely flammable.) oils being measured (see 10.3).
10.2 Initial calibration, or calibration after a change in test
7.5 Petroleum Naphtha, for flushing viscous petroleum
samples from the sample tube. (Warning—Extremely flam- temperature, necessitates calculation of the values of the
Constants A and B from the periods of oscillation, (T),
mable.)
observed when the sample cell contains certified reference
NOTE 1—Suitable solvent naphthas are marketed under various desig-
liquids such as air and double-distilled boiled water. Other
nations such as “petroleum ether,” “ligroine,” or “precipitation naphtha.”
calibrating materials such as n-nonane, n-tridecane, cyclo-
7.6 n-Nonane, n-tridecane or cyclohexane, 99% purity or
hexane, and n-hexadecane (for high temperature applications)
better, or similar pure material for which the density is known
can also be used as appropriate.
precisely from literature references or by direct determination
10.2.1 While monitoring the oscillator period, T, flush the
in accordance with Test Method D941 or D1217.(Warning—
sampletubewithpetroleumnaphtha,followedwithanacetone
Extremely flammable.)
flush and dry with dry air. Continue drying until the display
exhibits a steady reading. In cases where saline components
can be deposited in the cell, flush with distilled water followed
Reagent Chemicals, American Chemical Society Specifications, American
Chemical Society, Washington, DC. For Suggestions on the testing of reagents not
by acetone and dry air. Contaminated or humid air can affect
listed by the American Chemical Society, see Annual Standards for Laboratory
the calibration. When these conditions exist in the laboratory,
Chemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeia
pass the air used for calibration through a suitable purification
and National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,
MD. and drying train. In addition, the inlet and outlet ports for the
D5002 − 99 (2010)
A
TABLE 1 Density of Water (in vacuo)
10.2.9 If the instrument is equipped to calculate density
Tempera- Density, Tempera- Density, Tempera- Density,
fromtheConstantsAandBandtheobserved T-valuefromthe
ture, °C g/mL ture, °C g/mL ture,° C g/mL
sample, then enter the constants in the instrument memory in
0.0 0.999840 21.0 0.997991 40.0 0.992212
accordance with the manufacturer’s instructions.
3.0 0.999964 22.0 0.997769 45.0 0.990208
4.0 0.999964 23.0 0.997537 50.0 0.988030
10.2.10 Check the calibration and adjust if needed by
5.0 0.999964 24.0 0.997295 55.0 0.985688
performing the routine calibration check described in 10.3.
10.0 0.999699 25.0 0.997043 60.0 0.983191
15.0 0.999099 26.0 0.996782 65.0 0.980546
10.2.11 To calibrate the instrument to determine relative
15.56 0.999012 27.0 0.996511 70.0 0.977759
density,thatis,thedensityofthesampleatagiventemperature
16.0 0.998943 28.0 0.996231 75.0 0.974837
referredtothedensityofwateratthesametemperature,follow
17.0 0.998774 29.0 0.995943 80.0 0.971785
18.0 0.998595 30.0 0.995645 85.0 0.968606
10.2.1-10.2.9, but substitute 1.000 for d in performing the
w
19.0 0.998404 35.0 0.994029 90.0 0.965305
calculations described in 10.2.8.
20.0 0.998203 37.78 0.993042 100.0 0.958345
A
DensitiesconformingtotheInternationalTemperatureScale1990(ITS90)were
10.3 Since some crude oils can be difficult to remove from
extracted from Appendix G, Standard Methods for Analysis of Petroleum and
thesampletube,frequentcalibrationchecksarerecommended.
Related Products, 1991, Institute of Petroleum, London.
These checks and any subsequent adjustments to Constants A
and B can be made if required, without repeating the calcula-
tion procedure.
NOTE 2—The need for a change in calibration is generally attributable
U-tubemustbepluggedduringmeasurementofthecalibration
todepositsinthesampletubethatarenotremovedbytheroutineflushing
air to prevent ingress of moist air.
procedure.AlthoughthisconditioncanbecompensatedforbyadjustingA
10.2.2 Allow the dry air in the U-tube to come to thermal
and B, as described below, it is good practice to clean the tube with warm
equilibrium with the test temperature and record the T-value chromic acid solution (Warning—Causes severe burns. A recognized
carcinogen.) whenever a major adjustment is required. Chromic acid
for air.
solution is the most effective cleaning agent; however, surfactant-type
10.2.3 Introduce about 0.7 mLof freshly boiled and cooled
cleaning fluids have also been used successfully.
double-distilled water into the sample tube from the bottom
opening using a suitable syringe. The water must be free of 10.3.1 Flush and dry the sample tube as described in 10.2.1
even the smallest air or gas bubbles. The sample tube shall be and allow the display to reach a steady reading. If the display
completely full. Allow the water to reach thermal equilibrium
does not exhibit the correct T-value or density for air at the
atthetesttemperatureandrecordthe T-valueforwaterandthe temperature of test, repeat the cleaning procedure or adjust the
test temperature.
value of Constant B commencing with the last decimal place
10.2.4 Alternatively introduce one of the hydrocarbon cali-
until the correct density is displayed.
bration standards and measure the T-value as in 10.2.3.
10.3.2 If adjustment to Constant B was necessary in 10.3.1
10.2.5 Calculate the density of air at the temperature of test
then continue the recalibration by introducing freshly boiled
using the following equation:
and cooled double-distilled water into the sample tube as
d 50.001293 273/T P/760 g/mL (1) described in 10.2.3 and allowing the display to reach a steady
@ #@ #
a
reading. If the instrument has been calibrated to display the
where:
density, adjust the reading to the correct value for water at the
T = temperature, K, and
test temperature (see Table 1) by changing the value of
P = barometric pressure, torr.
Constant A, commencing with the last decimal place. If the
10.2.6 Determine the density of water at the temperature of
instrument has been calibrated to display the relative density,
test by reference to Table 1.
adjust the reading to the value 1.0000.
10.2.7 Altern
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