ASTM D1480-93(1997)
(Test Method)Standard Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Bingham Pycnometer
Standard Test Method for Density and Relative Density (Specific Gravity) of Viscous Materials by Bingham Pycnometer
SCOPE
1.1 This test method describes two procedures for the measurement of the density of materials which are fluid at the desired test temperature. Its application is restricted to liquids of vapor pressures below 600 mm Hg (80 kPa) and viscosities below 40 000 cSt (mm /s) at the test temperature. The method is designed for use at any temperature between 20 and 100°C. It can be used at higher temperatures; however, in this case the precision section does not apply. Note 1-For the determination of density of materials which are fluid at normal temperatures, see Test Method D941 or where greater precision is desired see Test Method D1217.
1.2 This test method provides a calculation procedure for converting density to specific gravity.
1.3 The values stated in acceptable SI units are to be regarded as the standard.
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. For specific precautionary statements see Notes 1, 2, and 3.
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Designation:D1480–93 (Reapproved 1997) An American National Standard
AMERICAN SOCIETY FOR TESTING AND MATERIALS
100 Barr Harbor Dr., West Conshohocken, PA 19428
Reprinted from the Annual Book of ASTM Standards. Copyright ASTM
Standard Test Method for
Density and Relative Density (Specific Gravity) of Viscous
Materials by Bingham Pycnometer
This standard is issued under the fixed designation D1480; 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.
1. Scope 3.1.2 relative density (specific gravity)—the ratio of the
mass (weight in a vacuum) of a given volume of material at a
1.1 This test method describes two procedures for the
temperature, t , to the mass of an equal volume of water at a
measurement of the density of materials which are fluid at the
reference temperature, t ; or it is the ratio of the density of the
desired test temperature. Its application is restricted to liquids
material at t to the density of water at t . When the reference
1 2
of vapor pressures below 600 mm Hg (80 kPa) and viscosities
temperature is 4°C (the temperature at which the relative
below 40 000 cSt (mm /s) at the test temperature.The method
densityofwaterisunity),relativedensity(specificgravity)and
is designed for use at any temperature between 20 and 100°C.
density are numerically equal.
It can be used at higher temperatures; however, in this case the
precision section does not apply.
4. Summary of Test Method
NOTE 1—For the determination of density of materials which are fluid
4.1 The liquid sample is introduced into the pycnometer,
atnormaltemperatures,seeTestMethodD941orwheregreaterprecision
equilibrated to the desired temperature, and weighed. The
is desired see Test Method D1217.
density or specific gravity is then calculated from this weight
1.2 This test method provides a calculation procedure for
and the previously determined calibration factor, and a correc-
converting density to specific gravity.
tion is applied for the buoyancy of air.
1.3 The values stated in acceptable SI units are to be
5. Significance and Use
regarded as the standard.
1.4 This standard does not purport to address all of the
5.1 Density is a fundamental physical property that can be
safety concerns, if any, associated with its use. It is the
used in conjunction with other properties to characterize both
responsibility of the user of this standard to establish appro-
the light and heavy fractions of petroleum and to assess the
priate safety and health practices and determine the applica-
quality of crude oils.
bility of regulatory limitations prior to use. For specific
5.2 Determination of the density or relative density of
precautionary statements see Note 1, Note 2, and Note 3.
petroleum and its products is necessary for the conversion of
measured volumes to volumes at the standard temperatures of
2. Referenced Documents
15°C.
2.1 ASTM Standards:
5.3 The determination of densities at the elevated tempera-
D941 Test Method for Density and Relative Density (Spe-
tures of 40 and 100°C is particularly useful in providing the
cific Gravity) of Liquids by Lipkin Bicapillary Pycnom-
data needed for the conversion of kinematic viscosities in
eter
centistokes (mm /s) to the corresponding dynamic viscosities
D1217 Test Method for Density and Relative Density
in centipoises (mPa·s).
(Specific Gravity) of Liquids by Bingham Pycnometer
6. Apparatus
E1 Specification for ASTM Thermometers
6.1 Pycnometer, Bingham-type of 10-mL capacity (as
3. Terminology
shown in Fig. 1 ), constructed of heat-resistant glass.
3.1 Definitions:
NOTE 2—Pycnometershavingcapacitiesof2to25mLareavailablebut
3.1.1 density—the weight in a vacuum (that is, the mass) of
have not been cooperatively evaluated.
a unit volume of the material at any given temperature.
6.2 Constant-Temperature Bath, provided with suitable py-
cnometer holders and means for maintaining temperatures
This test method is under the jurisdiction of ASTM Committee D-2 on
constant to 60.01°C in the desired range. Water-glycerin
Petroleum Products and Lubricantsand is the direct responsibility of Subcommittee
mixtures can be used for temperatures up to 100°C.
D02.04on Hydrocarbon Analysis.
Current edition approved Feb. 15, 1993. Published May 1993. Originally
published as D1480–57T. Last previous edition D1480–91.
In 1962, this test method was adopted as standard without revision. Available from Reliance Glass Co., 220 Gateway Rd., Bensonville, IL
Annual Book of ASTM Standards, Vol 05.01. 60106-0825.
3 5
Annual Book of ASTM Standards, Vol 14.03. Borosilicate glass has been found satisfactory for this purpose.
D1480
FIG. 1 Bingham-Type Pycnometer
6.3 Bath Thermometer,graduatedin0.1°Csubdivisionsand
standardized for the range of use to the nearest 0.01°C (ASTM
Metric Equivalents
Saybolt Viscosity Thermometers 17C to 22C, conforming to
the requirements in Specification E1, are recommended). For in. mm in. mm in. mm in. mm
most hydrocarbons the density coefficient is about 0.0008
1 5 1
⁄8 3.2 ⁄8 15.9 1 ⁄4 31.8 4 102
units/°C, and therefore an error of 60.013°C would cause an
1 3 7 3
⁄4 6.4 ⁄4 19.1 1 ⁄16 36.5 4 ⁄4 121
7 1 7 3
error of 60.00001 in density. ⁄16 11.1 1 ⁄32 26.2 1 ⁄8 47.6 5 ⁄8 136
1 1 3
⁄2 12.7 1 ⁄8 28.6 2 50.8 6 ⁄8 162
6.4 Thermal Shields, as shown in Fig. 2 , to hold the
7 ⁄4 184
pycnometer and syringe during the filling procedure, con-
structed of two aluminum shells with suitably spaced viewing
NOTE 1—Cover shields with mica or insulating cement.Wind with No.
ports,theupperboredtoholda30-mLhypodermicsyringeand
26 gage Chromel “A” wire: Upper block 60 in. (1.52 m) (25.4V), lower
block (85 in. (2.16 m) (35.0V) wound vertically. Cover with insulating
the lower bored to hold a 25-mL Bingham pycnometer. A
tape or insulating cement and connect heaters in series. Insulate shields
winding of No. 26 Chromel“ A” wire, insulated from the
from stand with ⁄4-in. Transite.
shields with mica, covered with insulating tape, and having
FIG. 2 Details of Thermal Shields for 30-mL Syringe and 25-mL
resistancesconnectedinseriesof25Vontheuppershieldand
Pycnometer
35V on the lower produces controlled heat to the shields by
meansofavariabletransformer.Astandisnecessarytosupport
of the balance arms. The same balance shall be used for all
theshieldsinsuchamannerthatthecenterofthewellsmaybe
related weighings.
aligned, and the upper shield raised 180 to 200 mm and swung
6.10 Weights, whose relative values are known to the
through 45°.
nearest 0.05 mg or better. Use the same set of weights for the
6.5 Hypodermic Syringes, 2 to 30-mL capacity, of chemi-
calibration of the pycnometer and the determination of densi-
cally resistant glass, equipped with a 170-mm, 16-gage (0.065
ties.
in.)fillingneedlemadefromstainless-steeltubing,asshownin
Fig. 3 .
7. Reagents and Materials
6.6 Draw-off Needle, made of stainless-steel tubing, as
7.1 Acetone—(Warning—See Note 3).
shown in Fig. 3.
6.7 Solvent Cleaning Assembly, as shown in Fig. 4 .
NOTE 3—Warning:Extremely flammable. Use adequate ventilation.
6.8 Chromic Acid Cleaning Apparatus, similar to that
7.2 Isopentane—(Warning—See Note 4).
shown in Fig. 5 .
6.9 Balance, capable of reproducing weighings within 0.1 NOTE 4—Warning:Extremely flammable. Avoid build up of vapors
and remove all sources of ignition, especially non-explosion proof
mg when carrying a load of 30 g. The balance shall be located
electrical apparatus.
in a room shielded from drafts and fumes and in which the
temperature changes between related weighings (empty and 7.3 Chromic Acid (Potassium Dichromate/Conc. Sulfuric
filledpycnometer)donotcauseasignificantchangeintheratio Acid)—(Warning—See Note 5).
D1480
FIG. 3 Accessories for Bingham-Type Pycnometer
NOTE 5—Warning:Causes severe burns.Arecognized carcinogen. Do
as indicated. Place the pycnometer on the cleaner with the
not get in eyes, on skin or clothing.
upper hypodermic needle extending upward into the pycnom-
eter, and press the edge of the ground joint on the rubber
8. Preparation ofApparatus
stopper until the vacuum holds it in place. Draw out all the
8.1 Clean the pycnometer thoroughly with hot chromic acid
liquid or sample. Immerse the lower end of the hypodermic
cleaning solution by means of the assembly shown in Fig. 5
tube in a suitable solvent and draw 20 to 25 mL through the
(Warning—See Note 5). Chromic acid solution is the most
pycnometer.Leavingthepycnometerinplace,drawairthrough
effective cleansing agent. However, surfactant cleansing fluids
it until it is dry. Clean the hypodermic syringe with the same
have also been used successfully. Mount the apparatus firmly
apparatus.
and connect the trap to the vacuum. Warm the necessary
amountofcleaningacidinthebeaker,placethepycnometeron
9. Calibration of Pycnometers
the ground joint, and evacuate by opening the stopcock to
9.1 Weigh the clean, dry pycnometer to 0.1 mg and record
vacuum. Fill the pycnometer with acid by turning the stop-
the weight.
cock, and either repeat several times, or remove the filled
NOTE 6—It is convenient to use the lightest of a set of pycnometers as
pycnometer and allow it to stand for several hours at 50 to
a tare. For best results the treatment and environment of both pycnometer
60°C. Remove the acid from the pycnometer by evacuation,
and tare should be identical for some time prior to weighing.
empty the acid from the trap, and flush the pycnometer with
distilled water. Clean in this manner whenever the pycnometer 9.2 With a syringe of suitable size, transfer freshly boiled
istobecalibratedorwheneverliquidfailstodraincleanlyfrom andcooleddistilledwatertothepycnometerthroughthefilling
the walls of the pycnometer or its capillary. Ordinarily, the needle (Note 9). Avoid trapping air bubbles in the bulb or
pycnometer may be cleaned between determinations by wash- capillary of the pycnometer, removing bubbles, as they form,
ing with a suitable solvent, rinsing with pure, dry acetone, with the syringe, when possible.Also remove any water above
followed by isopentane, and vacuum drying. (Warning—See the calibration mark and dry the overflow chamber and
Note 3 and Note 4.) capillary with a cotton-fiber pipe cleaner or cotton swab which
8.2 Transfer the pycnometer to the cleaner assembly shown has been moistened slightly with acetone. Do not touch the
in Fig. 4, with vacuum line and trap attached to the side tube plunger of the syringe or hypodermic needle with fingers as
D1480
FIG. 4 Cleaner Assembly for Bingham-Type Pycnometer
FIG. 5 All-Glass Pycnometer Cleaner Assembly for Use with Hot Chromic Acid Cleaning Solution
minutequantitiesofoiltransferredthiswaywouldcausefaulty expands into the overflow chamber, remove the stopper, raise
drainage in the capillary neck of the pycnometer.
the pycnometer sufficiently to expose the calibration mark to
9.3 Close the pycnometer with the glass stopper and im-
view, and readjust the liquid level to the mark by withdrawing
merse it to a point above the calibration mark in the constant-
liquid through the steel draw-off needle until expansion has
temperature bath adjusted to a constancy of 60.01°C at the
stopped, indicating that the liquid has reached the temperature
desired temperature (Note 7). Periodically, or before the liquid
D1480
A
TABLE 2 Density of Water
of the thermostat. To minimize errors caused by faulty drain-
age, do not allow the liquid to expand more than 10 mm above Temperature, Density, Temperature, Density, Temperature, Density,
°C g/mL °C g/mL °C g/mL
the calibration mark at any time. Allow the contents to
equilibrate an additional 10 min and draw the level down
0 0.999840 21 0.997991 40 0.992212
3 0.999964 22 0.997769 45 0.990208
exactly to the calibration line, avoiding parallax and using a
4 0.999972 23 0.997537 50 0.988030
magnifier, if necessary, to obtain good visibility. Remove any
5 0.999964 24 0.997295 55 0.985688
liquid adhering to the walls above the calibration mark, with
10 0.999699 25 0.997043 60 0.983191
15 0.999099 26 0.996782 65 0.980546
the draw-off needle or pipe cleaner, depending upon the
15.56 0.999012 27 0.996511 70 0.977759
volatility of the sample. Portions in the overflow bulb can be
16 0.998943 28 0.996231 75 0.974837
removed with a cotton swab moistened with acetone. 17 0.998774 29 0.995943 80 0.971785
18 0.998595 30 0.995645 85 0.968606
NOTE 7—For temperatures above 80°C calculate the volume from the
19 0.998404 35 0.994029 90 0.965305
coefficient of expansion of the glass observed from calibrations made at 20 0.998203 37.78 0.993042 100 0.958345
60, 70, and 80°C. A
Densities conforming to the International Temperature Scale 1990 (ITS 90)
wereextractedfromAppendixG,StandardMethodsforAnalysisofPetroleumand
9.4 Replace the glass stopper, remove the pycnometer from
Related Products 1991
, Institute of Petroleum, London.
the bath, wash the outside surface with acetone, and dry
thoroughly with a chemically clean, lint-free, slightly damp
10.2 Warm,inanovenorconvenientwarmingchamber,the
cloth. Place the pycnometer in or near the balance case for 20
pycnometer, syringe with needle, and sample to a convenient
min and weigh to the nearest 0.1 mg.
working temperature consistent with the fluidity and volatility
NOTE 8—In atmospheres of low humidity (60% or lower), drying the
of sample. Draw the requisite amount of sample into the
pycnometer by rubbing with a dry cotton cloth will induce static charges
syringe and immediately fill the warmed pycnometer taking
equivalent to a loss of about 1 mg in the weight of the pycnometer. This
care to avoid occluding air bubbles in the pycnometer bulb or
charge may not be completely dissipated in less than 30 min. The use of
about 0.1 mg of radium bromide- or polonium-coated foil in the balance
capillary. Continue the addition of sample, withdrawing the
case, or maintaining the relative humidity at 60 percent or higher, aids in
filling needle gradually so that the tip remains immersed in the
reducing weighing difficulties due to static charges.
sample, until the sample has been added to a depth of 10 or 20
9.5 Calculatethepycnometercalibrationfactor,F,fromthe mm in the expansion chamber above the capillary, depending
t
equation: upon the amount of contraction expected.
10.3 Immerse the pycnometer bulb in the constant-
F 5~densityofwaterat t°C!/
t
temperature bath. As the sample contracts continue sample
~weightofwaterinpycnometerat t°C! (1)
addition bef
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