ASTM D891-18

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.
Designation: D891 −18
Standard Test Methods for
Specific Gravity, Apparent, of Liquid Industrial Chemicals
This standard is issued under the fixed designation D891; 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.
This standard has been approved for use by agencies of the U.S. Department of Defense.
1. Scope* D4052Test Method for Density, Relative Density, and API
Gravity of Liquids by Digital Density Meter
1.1 These test methods cover the determination of the
D6809Guide for Quality Control and Quality Assurance
specific gravity, apparent, of liquid industrial chemicals. Two
Procedures for Aromatic Hydrocarbons and Related Ma-
test methods are covered as follows:
terials
1.1.1 Test Method A, specific gravity, apparent, by means of
E1Specification for ASTM Liquid-in-Glass Thermometers
a hydrometer.
E100Specification for ASTM Hydrometers
1.1.2 Test Method B, specific gravity, apparent, by means of
E202Test Methods for Analysis of Ethylene Glycols and
a pycnometer.
Propylene Glycols
NOTE 1—Test Method D4052 describes an instrumental procedure.
E302Test Methods for Monobasic Organic Acids (With-
1.2 In common usage the term specific gravity, apparent, is drawn 2001)
E346Test Methods for Analysis of Methanol (Withdrawn
understood to mean specific gravity.
2017)
1.3 The values stated in SI units are to be regarded as
2.2 Other Document:
standard. No other units of measurement are included in these
OSHA Regulations, 29 CFRparagraphs 1910.1000 and
test methods with the exception of Fahrenheit (°F) in 5.1 as an
1910.1200
example of a possible industrial specification unit.
1.4 This standard does not purport to address all of the
3. Terminology
safety concerns, if any, associated with its use. It is the
3.1 Definitions of Terms Specific to This Standard:
responsibility of the user of this standard to establish appro-
3.1.1 specific gravity, apparent—the ratio of the weight in
priate safety, health, and environmental practices and deter-
air of a unit volume of a material at a stated temperature to the
mine the applicability of regulatory limitations prior to use.
weight in air of equal density of an equal volume of gas-free
For specific hazard statements, see Sections 8 and 16.
distilled water (see Note 2) at a stated temperature. It shall be
1.5 This international standard was developed in accor-
stated as follows:
dance with internationally recognized principles on standard-
o
Specificgravity, apparent, x/y C (1)
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom-
where x is the temperature of the material and y is the
mendations issued by the World Trade Organization Technical
temperature of the water.
Barriers to Trade (TBT) Committee.
NOTE 2—Gas-free distilled water is distilled water that has been boiled
to eliminate dissolved gases.
2. Referenced Documents
2.1 ASTM Standards: 4. Significance and Use
D1193Specification for Reagent Water
4.1 Specific gravity, apparent, may be used as a qualitative
testinestablishingtheidentityofachemical.Itmaybeusedto
calculate the volume occupied by a product whose weight is
These test methods are under the jurisdiction of ASTM Committee D16 on
known,ortocalculatetheweightofaproductfromitsvolume.
Aromatic, Industrial, Specialty and Related Chemicals and are the direct responsi-
Itmaybeusedtodeterminethecompositionofbinarymixtures
bility of Subcommittee D16.15 on Industrial and Specialty General Standards.
Current edition approved Aug. 1, 2018. Published August 2018. Originally
approved in 1946. Last previous edition approved in 2009 as D891–09 which was
withdrawn January 2018 and reinstated in August 2018. DOI: 10.1520/D0891-18. The last approved version of this historical standard is referenced on
For referenced ASTM standards, visit the ASTM website, www.astm.org, or www.astm.org.
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Available from U.S. Government Printing Office, Superintendent of
Standards volume information, refer to the standard’s Document Summary page on Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
the ASTM website. www.access.gpo.gov.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D891 − 18
of pure chemicals. In the case of most refined industrial Example: The specific gravity, apparent, of n-butanol at
chemicals specific gravity, apparent, is of minimal value in 20/20°C is 0.8108 and the change in specific gravity, apparent,
defining quality, although it may detect gross contamination. is 0.00074/°C. What is the specific gravity, apparent, at
4/20°C?
4.2 Of the two test methods described, the pycnometer
method (Test Method B, 1.1.2) is the most accurate and Specificgravity, apparent, at4/20°C 5 @ 20 24 0.00074#10.8108
~ !
precise. For this reason it is the preferred method in case of
50.8226 (3)
disputes.Thehydrometermethod(TestMethodA,1.1.1)isthe
TEST METHOD A—SPECIFIC GRAVITY,
leastaccurateandprecise,butitisalsothesimplestandfastest
APPARENT, BY MEANS OF A HYDROMETER
toperformandisoftenentirelysatisfactoryformanypurposes.
If the sample is too viscous to permit the hydrometer to float
6. Summary of Test Method
freely, the pycnometer test method should be used.
6.1 The specific gravity, apparent, of the sample is deter-
5. Test Temperatures
mined by immersing a calibrated hydrometer in the sample at
the test temperature. The displacement of the hydrometer is a
5.1 Specifications for industrial chemicals often specify
function of the specific gravity, apparent, of the sample that is
different temperatures at which specific gravity, apparent, shall
readonthehydrometerscaleatthelevelofthemeniscusofthe
be measured, for example:
sample.
Specific gravity, apparent, at 15.56/15.56°C,
Specific gravity, apparent, at 20/20°C,
7. Apparatus
Specific gravity, apparent, at 25/25°C, or
7.1 Hydrometer—Thehydrometerstobeusedshallbethose
Specific gravity, apparent, at 60/60°F.
specified in Specification E100, as follows:
Where precision is desired, it is necessary to determine the
Nominal Apparent Specific ASTM
specific gravity, apparent, at the temperature prescribed in the
Gravity Range Hydrometer No.
specifications for the material to be tested and to use instru-
0.650 to 0.700 82H-62
ments that have been calibrated and standardized at the 0.700 to 0.750 83H-62
0.750 to 0.800 84H-62
specified temperature.
0.800 to 0.850 85H-62
0.850 to 0.900 86H-62
5.2 The expression “specific gravity, apparent, at 25.0/
0.900 to 0.950 87H-62
15.56°C,” for example, means the ratio of the weight in air of
0.950 to 1.000 88H-62
a unit volume of a material at 25.0°C to the weight in air of
1.000 to 1.050 89H-62
1.050 to 1.100 90H-62
equal density of an equal volume of gas-free distilled water at
1.100 to 1.150 113H-62
15.56°C.
1.150 to 1.200 114H-62
1.200 to 1.250 115H-62
5.3 It is possible to convert the specific gravity, apparent, at
x/T °Ctothecorrespondingvalueatx/T °Cbymultiplyingthe NOTE3—TheASTMhydrometersprescribedinTestMethodA,7.1,are
1 2
calibrated as if all weights are in vacuum. Equivalent values at the same
valueat T bythefactorgiveninTable1.Forexample,aliquid
temperature for all weights in air may be approximated for ambient
has a specific gravity, apparent, of 0.9500 at 20/20°C and the
conditions as follows:
value at 20/4°C is desired: 0.9500×0.9982336=0.9483, the
apparentspecificgravity 51.00120 3 ~spgr! 20.00120
value at 20/4°C. The values in Table 1 are the ratios of the
density of water at the appropriate temperatures.
where:
sp gr = specific gravity determined by ASTM hydrometer.
5.4 Ifthechangeinspecificgravity,apparent,withtempera-
ture of the liquid is known, the specific gravity, apparent, at
7.2 Hydrometer Cylinder—The vessel in which the sample
T /ymaybeconvertedtothatatT /ybythefollowingequation:
1 2
forthegravitytestisconfirmedshallbemadeofclearglassand
Specificgravity, apparent, at T /y 5 T 2 T k shall be cylindrical in shape. For convenience in pouring, it
~ !
2 1 2
may have a lip on the rim.The inside diameter shall be at least
1specificgravity, apparent, at T /y
25 mm greater than the outside diameter of the hydrometer
(2)
used in it. The height of the cylinder shall be such that after
where:
equilibrium has been reached, the lowest point on the hydrom-
T = original temperature, °C, eter will be at least 25 mm off the bottom of the cylinder.
T = the second temperature, °C, and
7.3 Thermometer—The thermometers used shall be those
k = change in specific gravity, apparent, per °C.
specified in Specification E1. Thermometer 90C, a 76-mm
TABLE 1 Conversion of Specific Gravities, Apparent, from Basis x/T to Basis x/ T °C
1 2
Multiplied by This Factor Gives Specific Gravities, Apparent, on Basis x/T
Specific Gravities, 2
Apparent, on Basis x/T
1 t/4 t/15 t/15.56 t/20 t/25
t/4 1 1.0008722 1.0009586 1.0017695 1.0029335
t/15 0.9991286 1 1.0000864 1.0008966 1.0020595
t/15.56 0.9990423 0.9999136 1 1.0008101 1.0019730
t/20 0.9982336 0.9991042 0.9991905 1 1.0011619
t/25 0.9970751 0.9979447 0.9980309 0.9988395 1
D891 − 18
immersion thermometer, covering 0 to 30°C with 0.1°C 0.00020 unit at 24 DF. The 95% limit for the difference
graduations, is recommended for most work. Thermometer between two such runs is 0.0005 unit.
63Cissimilarexceptitisatotalimmersiontypeandcovers−8 11.1.3 Within-Laboratory, Between-Days Variability—The
to 30°C with 0.1°C graduations. standard deviation of results (each the average of duplicates),
obtained by the same analyst on different days, has been
7.4 Water Bath—A water bath capable of maintaining the
estimated to be 0.00016 unit at 12 DF. The 95% limits for the
selected test temperature 60.05°C.The depth of the bath must
difference between two such averages is 0.005 unit.
be sufficient to immerse the hydrometer cylinder so that the
11.1.4 Reproducibility (Multilaboratory)—The standard de-
contained liquid is completely below the surface of the liquid
viation of results (each the average of duplicates), obtained by
in the bath.
analysts in different laboratories, has been estimated to be
0.00057unitat5DF.The95%limitforthedifferencebetween
8. Hazards
two such averages is 0.0015 unit.
8.1 Consult current OSHA regulations, suppliers’ Safety
11.2 Bias—The bias of this test method has not been
Data Sheets, and local regulations for all materials used in this
determined due to the unavailability of suitable reference
test method.
materials. However, the bias is dependent upon the calibration
of the hydrometer and the degree of control of the temperature
9. Procedure
of the hydrometer bath.
9.1 Cool the sample in the original container to about 2°C
below the temperature at which the specific gravity, apparent,
12. Quality Guidelines
is to be determined. Rinse each piece
...