ASTM D287-92(2000)e1

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn
Contact ASTM International (www.astm.org) for the lastest information
e1
Designation:D287–92(Reapproved 2000) An American National Standard
Standard Test Method for
API Gravity of Crude Petroleum and Petroleum Products
(Hydrometer Method)
This standard is issued under the fixed designation D287; 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 (e) indicates an editorial change since the last revision or reapproval.
This test method has been adopted for use by government agencies to replace Method 401 of Federal Test Method Standard No. 791b.
e NOTE—Editorial corrections were made throughout in April 2000.
1. Scope E100 Specification for ASTM Hydrometers
2.2 IP Standards:
1.1 This test method covers the determination by means of
Specifications for IP Standard Thermometers
a glass hydrometer of the API gravity of crude petroleum and
IP Specifications for Petroleum Hydrometers
petroleum products normally handled as liquids and having a
Reid vapor pressure (Test Method D323) of 26 psi (180 kPa)
3. Terminology
or less. Gravities are determined at 60°F (15.56°C), or con-
3.1 Definitions:
verted to values at 60°F, by means of standard tables. These
3.1.1 API gravity—a special function of relative density
tables are not applicable to nonhydrocarbons or essentially
(specific gravity) 60/60°F (15.56/15.56°C), represented by:
pure hydrocarbons such as the aromatics.
APIgravity,deg5~141.5/spgr60/60°F!2131.5 (1)
NOTE 1—The international version of this test method is described in
Practice D1298. No statement of reference temperature is required, since
60°F is included in the definition.
1.2 Values stated in inch-pound units are to be regarded as
the standard. The values given in parentheses are provided for
4. Summary of Test Method
information purposes only.
4.1 This test method is based on the principle that the
1.3 This standard does not purport to address all of the
gravity of a liquid varies directly with the depth of immersion
safety concerns, if any, associated with its use. It is the
of a body floating in it. The floating body, which is graduated
responsibility of the user of this standard to establish appro-
byAPI gravity units in this method, is called anAPI hydrom-
priate safety and health practices and determine the applica-
eter.
bility of regulatory limitations prior to use. For specific hazard
4.2 TheAPI gravity is read by observing the freely floating
statements, see 8.3.
API hydrometer and noting the graduation nearest to the
apparent intersection of the horizontal plane surface of the
2. Referenced Documents
liquid with the vertical scale of the hydrometer, after tempera-
2.1 ASTM Standards:
ture equilibrium has been reached. The temperature of the
D323 Test Method for Vapor Pressure of Petroleum Prod-
2 sample is read from a separate accurateASTM thermometer in
ucts (Reid Method)
thesampleorfromthethermometerwhichisanintegralpartof
D1250 Guide for Petroleum Measurement Tables
the hydrometer (thermohydrometer).
D1298 Practice for Density, Relative Density (Specific
Gravity), or API Gravity of Crude Petroleum and Liquid
5. Significance and Use
Petroleum Products by Hydrometer Method
5.1 Accurate determination of the gravity of petroleum and
E1 Specification for ASTM Thermometers
its products is necessary for the conversion of measured
volumes to volumes at the standard temperature of 60°F
(15.56°C).
This test method is under the jurisdiction of ASTM Committee D02 on
5.2 Gravity is a factor governing the quality of crude oils.
PetroleumProductsandLubricants,andisthedirectresponsibilityofSubcommittee
However, the gravity of a petroleum product is an uncertain
D02.04 on Hydrocarbon Analysis.
Current edition adopted Aug. 15, 1992. Published October 1992. Originally
published as D 287 – 28 T, replacing former D 47. Last previous edition
e1
D287–82(1987) .
2 4
Annual Book of ASTM Standards, Vol 05.01. Available from the Institute of Petroleum, 61 New Cavendish St., London
Annual Book of ASTM Standards, Vol 14.03. WIM, 8AR, England.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D287
indication of its quality. Correlated with other properties, a rubber aspirator bulb. Remove any air bubbles formed, after
gravity can be used to give approximate hydrocarbon compo- they have collected on the surface of the sample, by touching
sition and heat of combustion. them with a piece of clean filter paper before inserting the
hydrometer. For field testing, make the gravity measurement
6. Apparatus
directlyinthesamplingthief.Placethecylindercontainingthe
6.1 Hydrometers, of glass, graduated in degrees API as sampleinaverticalpositioninalocationfreefromaircurrents.
listed in Table 1 and conforming to Specification E100, or the Takeprecautionstopreventthetemperatureofthesamplefrom
IP Specifications for Petroleum Hydrometers. changing appreciably during the time necessary to complete
6.2 Thermometers, having a range from−5 to+215°F and the test. During this period, the temperature of the surrounding
conforming to the requirements for Thermometer 12F as
medium should not change more than 5°F (2°C).
prescribed in Specification E1 or Thermometer 64F of the 8.4 Lower the hydrometer gently into the sample and, when
SpecificationsforIPStandardThermometers.Athermometeris
ithassettled,depressitabouttwoscaledivisionsintotheliquid
not required if a thermohydrometer is employed. andthenreleaseit;keeptherestofthestemdry,asunnecessary
liquid on the stem changes the effective weight of the instru-
NOTE 2—TheASTM GravityThermometer 12F has 0.5°F subdivisions
ment, and so affects the reading obtained.With samples of low
and allowable 60.25°F scale error. The thermometers incorporated in
viscosity, a slight spin imparted to the instrument on releasing
thermohydrometers have 2°F subdivisions and allowable 61°F scale
error. assistsinbringingittorest,floatingfreelyawayfromthewalls
of the hydrometer cylinder. Allow sufficient time for the
6.3 Hydrometer Cylinders, of metal, clear glass, or plastic.
hydrometer to become completely stationary and for all air
Forconvenience inpouring,thecylindermayhavealiponthe
bubblestocometothesurface.Thisisparticularlynecessaryin
rim.Theinsidediameterofthecylindershallbeatleast25mm
the case of the more viscous samples.
greater than the outside diameter of the hydrometer used in it.
8.5 When the hydrometer has come to rest, floating freely,
The height of the cylinder shall be such that the length of the
and the temperature of the sample is constant to 0.2°F (0.1°C),
column of sample it contains is greater by at least 25 mm than
read the hydrometer to the n
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