ASTM D1298-12b(2017)e1

Standard Test Method for Density, Relative Density, or API Gravity of Crude Petroleum and Liquid Petroleum Products by Hydrometer Method

SIGNIFICANCE AND USE
5.1 Accurate determination of the density, relative density (specific gravity), or API gravity of petroleum and its products is necessary for the conversion of measured volumes to volumes or masses, or both, at the standard reference temperatures of 15 °C or 60 °F during custody transfer.  
5.2 This procedure is most suitable for determining the density, relative density (specific gravity), or API gravity of low viscosity transparent liquids. This procedure can also be used for viscous liquids by allowing sufficient time for the hydrometer to reach temperature equilibrium, and for opaque liquids by employing a suitable meniscus correction. Additionally for both transparent and opaque fluids the readings shall be corrected for the thermal glass expansion effect and alternative calibration temperature effects before correcting to the reference temperature.  
5.3 When used in connection with bulk oil measurements, volume correction errors are minimized by observing the hydrometer reading at a temperature close to that of the bulk oil temperature.  
5.4 Density, relative density, or API gravity is a factor governing the quality and pricing of crude petroleum. However, this property of petroleum is an uncertain indication of its quality unless correlated with other properties.  
5.5 Density is an important quality indicator for automotive, aviation and marine fuels, where it affects storage, handling and combustion.
SCOPE
1.1 This test method covers the laboratory determination using a glass hydrometer in conjunction with a series of calculations, of the density, relative density, or API gravity of crude petroleum, petroleum products, or mixtures of petroleum and nonpetroleum products normally handled as liquids, and having a Reid vapor pressure of 101.325 kPa (14.696 psi) or less. Values are determined at existing temperatures and corrected to 15 °C or 60 °F by means of a series of calculations and international standard tables.  
1.2 The initial hydrometer readings obtained are uncorrected hydrometer readings and not density measurements. Readings are measured on a hydrometer at either the reference temperature or at another convenient temperature, and readings are corrected for the meniscus effect, the thermal glass expansion effect, alternative calibration temperature effects and to the reference temperature by means of the Petroleum Measurement Tables; values obtained at other than the reference temperature being hydrometer readings and not density measurements.  
1.3 Readings determined as density, relative density, or API gravity can be converted to equivalent values in the other units or alternative reference temperatures by means of Interconversion Procedures (API MPMS Chapter 11.5), or Adjunct to D1250 Guide for Petroleum Measurement Tables (API MPMS Chapter 11.1), or both, or tables, as applicable.  
1.4 The initial hydrometer readings determined in the laboratory shall be recorded before performing any calculations. The calculations required in Section 10 shall be applied to the initial hydrometer reading with observations and results reported as required by Section 11 prior to use in a subsequent calculation procedure (ticket calculation, meter factor calculation, or base prover volume determination).  
1.5 Annex A1 contains a procedure for verifying or certifying the equipment for this test method.  
1.6 The values stated in SI units are to be regarded as standard.  
1.6.1 Exception—The values given in parentheses are provided for information only.  
1.7 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.  
1.8 This international standard was developed in accordance with internationally recognized principles on standardization established in th...

General Information

• Status: Published
• Publication Date: 14-Jul-2017
• ICS: 75.040 - Crude petroleum
• ICS: 75.080 - Petroleum products in general
• Technical Committee: D02 - Petroleum Products, Liquid Fuels, and Lubricants
• Drafting Committee: D02.02 - Hydrocarbon Measurement for Custody Transfer (Joint ASTM-API)

Relations

• Refers: ASTM E100-19 - Standard Specification for ASTM Hydrometers
• Effective Date: 01-May-2019
• Refers: ASTM D1250-19e1 - Standard Guide for the Use of the Joint API and ASTM Adjunct for Temperature and Pressure Volume Correction Factors for Generalized Crude Oils, Refined Products, and Lubricating Oils: API MPMS Chapter 11.1
• Effective Date: 01-May-2019
• Refers: ASTM E100-15a - Standard Specification for ASTM Hydrometers
• Effective Date: 01-Dec-2015
• Refers: ASTM E100-15 - Standard Specification for ASTM Hydrometers
• Effective Date: 01-Aug-2015
• Refers: ASTM E100-14 - Standard Specification for ASTM Hydrometers
• Effective Date: 01-May-2014
• Refers: ASTM E1-13 - Standard Specification for ASTM Liquid-in-Glass Thermometers
• Effective Date: 01-May-2013
• Refers: ASTM D4057-06(2011) - Standard Practice for Manual Sampling of Petroleum and Petroleum Products
• Effective Date: 01-Jun-2011
• Refers: ASTM E100-10 - Standard Specification for ASTM Hydrometers
• Effective Date: 01-Nov-2010
• Refers: ASTM D5854-96(2010) - Standard Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
• Effective Date: 01-May-2010
• Refers: ASTM E1-07 - Standard Specification for ASTM Liquid-in-Glass Thermometers
• Effective Date: 01-Nov-2007
• Refers: ASTM D1250-07 - Standard Guide for Use of the Petroleum Measurement Tables
• Effective Date: 01-May-2007
• Refers: ASTM E1-05 - Standard Specification for ASTM Liquid-in-Glass Thermometers
• Effective Date: 01-Nov-2005
• Refers: ASTM D5854-96(2005) - Standard Practice for Mixing and Handling of Liquid Samples of Petroleum and Petroleum Products
• Effective Date: 01-Jun-2005
• Refers: ASTM E100-05 - Standard Specification for ASTM Hydrometers
• Effective Date: 01-May-2005
• Refers: ASTM D1250-04 - Standard Guide for Use of the Petroleum Measurement Tables
• Effective Date: 01-May-2004

Overview

ASTM D1298-12b(2017)e1 is the internationally recognized standard for determining the density, relative density (specific gravity), or API gravity of crude petroleum and liquid petroleum products using the hydrometer method. Developed by ASTM International, this method is critical for the accurate measurement and conversion of volumes or masses during custody transfer, quality assessment, and pricing of petroleum products.

The procedure utilizes a glass hydrometer to obtain readings, which are then corrected to standard reference temperatures (15 °C or 60 °F) using international calculation tables, ensuring standardized results across the oil and gas industry.

Key Topics

• Hydrometer Method: The test involves immersing a glass hydrometer into a petroleum sample to measure its density or API gravity at a given temperature.
• Corrections and Calibration: Initial readings are uncorrected and must be adjusted for meniscus effect, thermal glass expansion, calibration temperature, and then converted to a standard reference temperature using the Petroleum Measurement Tables.
• Applicability: The method is ideal for:
  • Low viscosity, transparent petroleum liquids
  • Opaque or viscous samples, using meniscus corrections or temperature equilibrium adjustments
• Quality and Pricing Impact: Density, relative density, and API gravity are critical factors in product quality, storage, handling, combustion efficiency, and market value.
• Reference Standards and Traceability: The method ensures traceability to international standards (e.g., NIST), supporting global consistency and regulatory compliance.

Applications

The ASTM D1298 standard is widely applied across the petroleum, automotive, aviation, and marine fuel industries for:

• Custody Transfer: Essential for converting measured volumes to volumes or masses at standard conditions during transactions between producers, refiners, and distributors.
• Quality Control: Ensures fuels meet specification requirements for density and API gravity, impacting performance and regulatory acceptance.
• Product Blending: Facilitates the accurate blending of crude and refined products based on standardized density values.
• Operational Safety and Efficiency: Proper density measurements are critical for safe storage, optimal engine combustion, and handling of fuels.
• Regulatory Compliance: Supports reporting in line with international trade and environmental requirements, including WTO and API guidelines.

Related Standards

ASTM D1298 references a range of supporting standards for sample handling, equipment, and calculations, ensuring consistency and accuracy throughout the testing process:

• ASTM D1250 / API MPMS Chapter 11.1: Guide for the use of petroleum measurement tables for volume correction factors.
• ASTM D4057 / API MPMS Chapter 8.1: Manual sampling of petroleum and petroleum products.
• ASTM D4177 / API MPMS Chapter 8.2: Automatic sampling.
• ASTM D5854 / API MPMS Chapter 8.3: Guidance on the mixing and handling of samples.
• ISO 649-1: International specification for laboratory glass hydrometers.
• API MPMS Chapter 11.5: Procedures for interconversion of density, weight, and volume.
• ASTM E100 & E1: Specifications for hydrometers and liquid-in-glass thermometers.

Practical Value

Implementing ASTM D1298 enables organizations to:

• Achieve reliable, repeatable, and standardized density and API gravity measurements
• Support accurate financial transactions and inventory management in the oil and gas sector
• Ensure product quality and optimize fuel properties for various industrial applications
• Maintain conformance with industry regulations and international trade standards

By adhering to this standard, stakeholders across the petrochemical value chain enhance measurement accuracy, facilitate transparent trade, and drive operational excellence.

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.
´1
Designation: D1298 − 12b (Reapproved 2017)
Manual of Petroleum Measurement Standards (MPMS), Chapter 9.1
Standard Test Method for
Density, Relative Density, or API Gravity of Crude Petroleum
and Liquid Petroleum Products by Hydrometer Method
This standard is issued under the fixed designation D1298; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
ε NOTE—Editorially corrected adjunct information in March 2023.
1. Scope The calculations required in Section 10 shall be applied to the
initial hydrometer reading with observations and results re-
1.1 This test method covers the laboratory determination
ported as required by Section 11 prior to use in a subsequent
using a glass hydrometer in conjunction with a series of
calculation procedure (ticket calculation, meter factor
calculations, of the density, relative density, or API gravity of
calculation, or base prover volume determination).
crude petroleum, petroleum products, or mixtures of petroleum
and nonpetroleum products normally handled as liquids, and 1.5 Annex A1 contains a procedure for verifying or certify-
having a Reid vapor pressure of 101.325 kPa (14.696 psi) or ing the equipment for this test method.
less. Values are determined at existing temperatures and
1.6 The values stated in SI units are to be regarded as
corrected to 15 °C or 60 °F by means of a series of calculations
standard.
and international standard tables.
1.6.1 Exception—The values given in parentheses are pro-
1.2 The initial hydrometer readings obtained are uncor- vided for information only.
rected hydrometer readings and not density measurements.
1.7 This standard does not purport to address all of the
Readings are measured on a hydrometer at either the reference
safety concerns, if any, associated with its use. It is the
temperature or at another convenient temperature, and readings
responsibility of the user of this standard to establish appro-
are corrected for the meniscus effect, the thermal glass expan-
priate safety and health practices and determine the applica-
sion effect, alternative calibration temperature effects and to the
bility of regulatory limitations prior to use.
reference temperature by means of the Petroleum Measurement
1.8 This international standard was developed in accor-
Tables; values obtained at other than the reference temperature
dance with internationally recognized principles on standard-
being hydrometer readings and not density measurements.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
1.3 Readings determined as density, relative density, or API
mendations issued by the World Trade Organization Technical
gravity can be converted to equivalent values in the other units
Barriers to Trade (TBT) Committee.
or alternative reference temperatures by means of Interconver-
sion Procedures (API MPMS Chapter 11.5), or Adjunct to
2. Referenced Documents
D1250 Guide for Petroleum Measurement Tables (API MPMS
Chapter 11.1), or both, or tables, as applicable.
2.1 ASTM Standards:
D1250 Guide for the Use of the Joint API and ASTM
1.4 The initial hydrometer readings determined in the labo-
Adjunct for Temperature and Pressure Volume Correction
ratory shall be recorded before performing any calculations.
Factors for Generalized Crude Oils, Refined Products, and
Lubricating Oils: API MPMS Chapter 11.1
This test method is under the jurisdiction of ASTM Committee D02 on
D4057 Practice for Manual Sampling of Petroleum and
Petroleum Products, Liquid Fuels, and Lubricants and the API Committee on
Petroleum Products
Petroleum Measurement, and is the direct responsibility of Subcommittee D02.02
/COMQ, the joint ASTM-API Committee on Hydrocarbon Measurement for
Custody Transfer (Joint ASTM-API). This test method has been approved by the
sponsoring committees and accepted by the Cooperating Societies in accordance
with established procedures. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved July 15, 2017. Published July 2017. Originally contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM
approved in 1953. Last previous edition approved in 2012 as D1298 – 12b. DOI: Standards volume information, refer to the standard’s Document Summary page on
10.1520/D1298-12BR17E01. the ASTM website.
© Jointly copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, USA and the American Petroleum Institute (API), 1220 L Street NW, Washington DC 20005, USA
´1
D1298 − 12b (2017)
D4177 Practice for Automatic Sampling of Petroleum and 3.1.3.1 Discussion—Other reference temperatures, such as
Petroleum Products 20 °C, may be used for some products or in some locations.
D5854 Practice for Mixing and Handling of Liquid Samples Less preferred units of measurement (for example, kg/L or
of Petroleum and Petroleum Products g/mL) are still in use.
E1 Specification for ASTM Liquid-in-Glass Thermometers
3.1.4 hydrometer reading, n—the point on the hydrometer
E100 Specification for ASTM Hydrometers
scale at which the surface of the liquid cuts the scale.
2.2 API Standards:
3.1.4.1 Discussion—In practice for transparent fluids this
MPMS Chapter 8.1 Manual Sampling of Petroleum and
can be readily determined by aligning the surface of the liquid
Petroleum Products (ASTM Practice D4057)
on both sides of the hydrometer and reading the Hydrometer
MPMS Chapter 8.2 Automatic Sampling of Petroleum and
scale where these surface readings cut the scale (Hydrometer
Petroleum Products (ASTM Practice D4177)
Reading – Observed). For nontransparent fluids the point at
MPMS Chapter 8.3 Mixing and Handling of Liquid Samples
which the liquid surface cuts the Hydrometer scale cannot be
of Petroleum and Petroleum Products (ASTM Practice
determined directly and requires a correction (Meniscus Cor-
D5854)
rection). The value represented by the point (Meniscus Read-
MPMS Chapter 11.1 Temperature and Pressure Volume Cor-
ing) at which the liquid sample rises above the main surface of
rection Factors for Generalized Crude Oils, Refined Prod-
the liquid subtracted from the value represented by where the
ucts and Lubricating Oils (Adjunct to ASTM D1250)
main surface of the liquid cuts the Hydrometer scale is the
MPMS Chapter 11.5 Density/Weight/Volume Intraconver-
amount of the correction or Meniscus correction. This menis-
sion
cus correction is documented and then subtracted from the
2.3 Energy Institute Standards: value represented by the Meniscus Reading to yield the
Hydrometer Reading corrected for the Meniscus (Hydrometer
IP 389 Determination of wax appearance temperature
(WAT) of middle distillate fuels by differential thermal Reading – Observed, Meniscus Corrected).
analysis (DTA) or differential scanning calorimetry (DSC)
3.1.5 observed values, n—values observed at temperatures
IP Standard Methods Book, Appendix A, Specifications – IP
other than the specified reference temperature. These values are
Standard Thermometers
only hydrometer readings and not density, relative density
2.4 ISO Standards:
(specific gravity), or API gravity at that other temperature.
ISO 649-1 Laboratory glassware – Density hydrometers for
3.1.6 pour point, n—lowest temperature at which a test
general purpose – Part 1: Specification
portion of crude petroleum or petroleum product will continue
2.5 ASTM Adjuncts:
to flow when it is cooled under specified conditions.
Adjunct to D1250 Standard Guide for the Use of the Joint
3.1.7 relative density (specific gravity), n—the ratio of the
API and ASTM Adjunct for Temperature and Pressure
mass of a given volume of liquid at a specific temperature to
Volume Correction Factors for Generalized Crude Oils,
the mass of an equal volume of pure water at the same or
Refined Products, and Lubricant Oils: API MPMS Chapter
different temperature. Both reference temperatures shall be
11.1, Addenda 1 and 2
explicitly stated.
3.1.7.1 Discussion—Common reference temperatures in-
3. Terminology
clude 60/60 °F, 20 ⁄20 °C, 20/4 °C. The historic deprecated
3.1 Definitions of Terms Specific to This Standard:
term specific gravity may still be found.
3.1.1 API gravity, n—a special function of relative density
3.1.8 wax appearance temperature (WAT), n—temperature
(specific gravity) 60/60 °F, represented by:
at which waxy solids form when a crude petroleum or
°API 5 @141.5/ relative density 60/60 °F # 2 131.5 (1)
~ !
petroleum product is cooled under specified conditions.
3.1.1.1 Discussion—No statement of reference temperature
is required, as 60 °F is included in the definition.
4. Summary of Test Method
3.1.2 cloud point, n—temperature at which a cloud of wax
4.1 The sample is brought to a specified temperature and a
crystals first appears in a liquid when it is cooled under specific
test portion is transferred to a hydrometer cylinder that has
conditions.
been brought to approximately the same temperature. The
3.1.3 density, n—the mass of liquid per unit volume at 15 °C
appropriate hydrometer and thermometer, also at a similar
and 101.325 kPa with the standard unit of measurement being
temperature, are lowered into the test portion and allowed to
kilograms per cubic metre.
settle. After temperature equilibrium has been reached, the
hydrometer scale is read, and the temperature of the test
portion is taken. The observed hydrometer reading is corrected
Published as Manual of Petroleum Measurement Standards. Available from the
for the meniscus effect, the thermal glass expansion effect,
American Petroleum Institute (API), 1220 L St., NW, Washington, DC 20005-4070,
alternative calibration temperature effects and then reduced to
http://www.api.org.
the reference temperature by means of the volume correction
Available from Energy Institute, 61 New Cavendish St., London, W1G 7AR,
U.K., http://www.energyinst.org.
factors or tables as applicable by use of the appropriate Adjunct
Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
to D1250 Guide for Petroleum Measurement Tables (API
4th Floor, New York, NY 10036, http://www.ansi.org.
MPMS Chapter 11.1) and observed temperature from the
Available from ASTM International Headquarters. Order Adjunct No.
ADJD1250-A1A2-E-PDF. Original adjunct produced in 1983. thermometer.
´1
D1298 − 12b (2017)
4.2 If necessary, the hydrometer cylinder and its contents native calibration temperature effects shall be applied to the
are placed in a constant temperature bath to avoid excessive observed readings prior to corrections. Instruments that satisfy
temperature variation during the test. the requirements of this test method, but are not provided with
a recognized calibration certificate, are classed as uncertified.
5. Significance and Use
6.2 Thermometers, having range, graduation intervals and
5.1 Accurate determination of the density, relative density
maximum permitted scale error shown in Table 2 and conform-
(specific gravity), or API gravity of petroleum and its products
ing to Specification E1 or IP Appendix A.
is necessary for the conversion of measured volumes to
6.2.1 Alternative measuring devices or systems may be
volumes or masses, or both, at the standard reference tempera-
used, provided that the total uncertainty of the calibrated
tures of 15 °C or 60 °F during custody transfer.
system is no greater than that specified in 6.2. The stated
repeatability and reproducibility values are not applicable if
5.2 This procedure is most suitable for determining the
alternative fluids are used in the liquid-in-glass thermometers.
density, relative density (specific gravity), or API gravity of
low viscosity transparent liquids. This procedure can also be
6.3 Hydrometer Cylinder, clear glass, or plastic (see 6.3.1).
used for viscous liquids by allowing sufficient time for the
The inside diameter of the cylinder shall be at least 25 mm
hydrometer to reach temperature equilibrium, and for opaque
greater than the outside diameter of the hydrometer and the
liquids by employing a suitable meniscus correction. Addition-
height shall be such that the appropriate hydrometer floats in
ally for both transparent and opaque fluids the readings shall be
the sample test portion with at least 25 mm clearance between
corrected for the thermal glass expansion effect and alternative
the bottom of the hydrometer and the bottom of the cylinder.
calibration temperature effects before correcting to the refer-
6.3.1 Hydrometer cylinders constructed of plastic materials
ence temperature.
shall be resistant to discoloration or attack by oil samples and
shall not affect the material being tested. They shall not become
5.3 When used in connection with bulk oil measurements,
opaque under prolonged exposure to sunlight.
volume correction errors are minimized by observing the
hydrometer reading at a temperature close to that of the bulk oil
6.4 Constant-Temperature Bath, if required, of dimensions
temperature.
such that it can accommodate the hydrometer cylinder with the
test portion fully immersed below the test portion liquid
5.4 Density, relative density, or API gravity is a factor
surface, and a temperature control system capable of maintain-
governing the quality and pricing of crude petroleum.
ing the bath temperature within 0.25 °C of the test temperature
However, this property of petroleum is an uncertain indication
throughout the duration of the test.
of its quality unless correlated with other properties.
6.5 Stirring Rod, optional, of glass or plastic, approximately
5.5 Density is an important quality indicator for automotive,
400 mm in length.
aviation and marine fuels, where it affects storage, handling
and combustion.
7. Sampling
6. Apparatus
7.1 Unless otherwise specified, samples of non-volatile
petroleum and petroleum products shall be taken by the
6.1 Hydrometers, of glass, graduated in units of density,
procedures described in Practice D4057 (API MPMS Chapter
relative density, or API gravity as required, conforming to
8.1) and D4177 (API MPMS Chapter 8.2).
Specification E100 or ISO 649-1, and the requirements given
in Table 1.
7.2 Samples of volatile crude petroleum or petroleum prod-
6.1.1 The user should ascertain that the instruments used for
ucts are preferably taken by Practice D4177 (API MPMS
this procedure conform to the requirements set out above with
Chapter 8.2), using a variable volume (floating piston) sample
respect to materials, dimensions, and scale errors. In cases
receiver to minimize any loss of light components which may
where the instrument is provided with a calibration certificate
affect the accuracy of the density measurement. In the absence
issued by a recognized standardizing body, the instrument is
of this facility, extreme care shall be taken to minimize these
classed as certified and the appropriate corrections for the
losses, including the transfer of the sample to a chilled
meniscus effect, the thermal glass expansion effect, and alter-
container immediately after sampling.
7.3 Sample Mixing—May be necessary to obtain a test
TABLE 1 Recommended Hydrometers
portion representative of the bulk sample to be tested, but
A
Units Range Scale Meniscus
precautions shall be taken to maintain the integrity of the
Each
A A sample during this operation. Mixing of volatile crude petro-
Total Interval Error Correction
Unit
leum or petroleum products containing water or sediments, or
Density, kg/m at 15 °C 600 - 1100 20 0.2 ± 0.2 +0.3
both, or the heating of waxy volatile crude petroleum or
600 - 1100 50 0.5 ± 0.3 +0.7
600 - 1100 50 1.0 ± 0.6 +1.4
Relative density, 60/60 °F 0.600 - 1.100 0.020 0.0002 ± 0.0002 +0.0003
TABLE 2 Recommended Thermometers
0.600 - 1.100 0.050 0.0005 ± 0.0003 +0.0007
0.600 - 1.100 0.050 0.001 ± 0.0006 +0.0014
Scale Range Graduation Interval Scale Error
Relative density, 60/60 °F 0.650 - 1.100 0.050 0.0005 ±0.0005 +0.0007
°C −1 – +38 0.1 ± 0.1
API Gravity −1 - +101 12 0.1 ± 0.1 -0.1
°C −20 – +102 0.2 ± 0.15
A
°F −5 – +215 0.5 ± 0.25
Interval and Error relate to Scale.
´1
D1298 − 12b (2017)
petroleum products may result in the loss of light components. 9.1.2 For crude petroleum, bring the sample close to the
The following subsections (7.3.1 to 7.3.4) will give some reference temperature or, if wax is present, to 9 °C above its
guidance on sample integrity maintenance. expected pour point or 3 °C above its expected cloud point or
7.3.1 Volatile Crude Petroleum and Petroleum Products WAT, whichever is higher.
Having an RVP Greater than 50 kPa—Mix the sample in its
NOTE 5—For crude petroleum an indication of the WAT can be found
original closed container in order to minimize the loss of light
using IP 389, with the modification of using 50 μL 6 5 μL of sample. The
components.
precision of WAT for crude petroleum using this technique has not been
determined.
NOTE 1—Mixing volatile samples in open containers will lead to loss of
light components and consequently affect the value of the density 9.2 Density Measurement:
obtained.
9.2.1 Bring the hydrometer cylinder and thermometer to
7.3.2 Waxy Crude Petroleum—If the petroleum has an within approximately 5 °C of the test temperature.
expected pour point above 10 °C, or a cloud point or WAT
9.2.2 Transfer the sample to the clean, temperature-
above 15 °C, warm the sample to a temperature that is
stabilized hydrometer cylinder without splashing, to avoid the
sufficient for ensuring the material is fluid enough to provide
formation of air bubbles, and minimize evaporation of the
adequate mixing without excessively heating the material that
lower boiling constituents of more volatile samples.
would otherwise compromise the integrity of the sample.
(Warning—Extremely flammable. Vapors may cause flash
Samples heated to 9 °C above its pour point, or 3 °C above its
fire!)
cloud point or WAT have been found to be suitable tempera-
9.2.3 Transfer highly volatile samples by siphoning or water
tures to warm samples prior to mixing. Whenever possible, mix
displacement. (Warning—Do not siphon by mouth as it could
the sample in its original closed container in order to minimize
result in ingestion of sample!)
the loss of light components.
9.2.3.1 Samples containing alcohol or other water-soluble
7.3.3 Waxy Distillate—Warm the sample to a temperature
materials should be placed into the cylinder by siphoning.
that is sufficient for ensurin
...