1、Designation: D 1480 02e1An American National StandardStandard Test Method forDensity and Relative Density (Specific Gravity) of ViscousMaterials by Bingham Pycnometer1This standard is issued under the fixed designation D 1480; the number immediately following the designation indicates the year ofori
2、ginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.e1NOTEOriginal footnote 4 was deleted editorially in June 2006, since the
3、re is no longer a sole supplier of the pycnometer.1. Scope1.1 This test method describes two procedures for themeasurement of the density of materials which are fluid at thedesired test temperature. Its application is restricted to liquidsof vapor pressures below 600 mm Hg (80 kPa) and viscositiesbe
4、low 40 000 cSt (mm2/s) at the test temperature. The methodis designed for use at any temperature between 20 and 100C.It can be used at higher temperatures; however, in this case theprecision section does not apply.NOTE 1For the determination of density of materials which are fluidat normal temperatu
5、res, see Test Method D 1217.1.2 This test method provides a calculation procedure forconverting density to specific gravity.1.3 The values stated in acceptable SI units are to beregarded as the standard.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with
6、its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements see Note 1 and Note 2.2. Referenced Documents2.1 ASTM Standards:2D 1217 Te
7、st Method for Density and Relative Density(Specific Gravity) of Liquids by Bingham PycnometerE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 densitythe weight in a vacuum (that is, the mass) ofa unit volume of the material at any given temperature.3.1.2 rela
8、tive density (specific gravity)the ratio of themass (weight in a vacuum) of a given volume of material at atemperature, t1, to the mass of an equal volume of water at areference temperature, t2; or it is the ratio of the density of thematerial at t1to the density of water at t2. When the referencete
9、mperature is 4C (the temperature at which the relativedensity of water is unity), relative density (specific gravity) anddensity are numerically equal.4. Summary of Test Method4.1 The liquid sample is introduced into the pycnometer,equilibrated to the desired temperature, and weighed. Thedensity or
10、specific gravity is then calculated from this weightand the previously determined calibration factor, and a correc-tion is applied for the buoyancy of air.5. Significance and Use5.1 Density is a fundamental physical property that can beused in conjunction with other properties to characterize bothth
11、e light and heavy fractions of petroleum and to assess thequality of crude oils.5.2 Determination of the density or relative density ofpetroleum and its products is necessary for the conversion ofmeasured volumes to volumes at the standard temperatures of15C.5.3 The determination of densities at the
12、 elevated tempera-tures of 40 and 100C is particularly useful in providing thedata needed for the conversion of kinematic viscosities incentistokes (mm2/s) to the corresponding dynamic viscositiesin centipoises (mPas).6. Apparatus6.1 Pycnometer, Bingham-type of 10-mL capacity (asshown in Fig. 1), co
13、nstructed of heat-resistant3glass.NOTE 2Pycnometers having capacities of 2 to 25 mLare available buthave not been cooperatively evaluated.6.2 Constant-Temperature Bath, provided with suitable py-cnometer holders and means for maintaining temperatures1This test method is under the jurisdiction of AST
14、M Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04.0D on Physical and Chemical Methods.Current edition approved Nov. 10, 2002. Published January 2003. Originallyapproved in 1957. Last previous edition approved in 1997 as D 148093(1997).2For ref
15、erenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.3Borosilicate glass has been found satisfactory for this purpose.1Cop
16、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.constant to 60.01C in the desired range. Water-glycerinmixtures can be used for temperatures up to 100C.6.3 Bath Thermometer, graduated in 0.1C subdivisions andstandardized for the range of
17、 use to the nearest 0.01C (ASTMSaybolt Viscosity Thermometers 17C to 22C, conforming tothe requirements in Specification E1, are recommended). Formost hydrocarbons the density coefficient is about 0.0008units/C, and therefore an error of 60.013C would cause anerror of 60.00001 in density.6.4 Thermal
18、 Shields, as shown in Fig. 2, to hold thepycnometer and syringe during the filling procedure, con-structed of two aluminum shells with suitably spaced viewingports, the upper bored to hold a 30-mLhypodermic syringe andthe lower bored to hold a 25-mL Bingham pycnometer. Awinding of No. 26 Chromel “A”
19、 wire, insulated from theshields with mica, covered with insulating tape, and havingresistances connected in series of 25 V on the upper shield and35 V on the lower produces controlled heat to the shields bymeans of a variable transformer.Astand is necessary to supportthe shields in such a manner th
20、at the center of the wells may bealigned, and the upper shield raised 180 to 200 mm and swungthrough 45.6.5 Hypodermic Syringes, 2 to 30-mL capacity, of chemi-cally resistant glass, equipped with a 170-mm, 16-gage (0.065in.) filling needle made from stainless-steel tubing, as shown inFig. 3.6.6 Draw
21、-off Needle, made of stainless-steel tubing, asshown in Fig. 3.6.7 Solvent Cleaning Assembly, as shown in Fig. 4.6.8 Chromic Acid Cleaning Apparatus, similar to thatshown in Fig. 5.6.9 Balance, capable of reproducing weighings within 0.1mg when carrying a load of 30 g. The balance shall be locatedin
22、 a room shielded from drafts and fumes and in which thetemperature changes between related weighings (empty andfilled pycnometer) do not cause a significant change in the ratioof the balance arms. The same balance shall be used for allrelated weighings.6.10 Weights, whose relative values are known t
23、o thenearest 0.05 mg or better. Use the same set of weights for thecalibration of the pycnometer and the determination of densi-ties.7. Reagents and Materials7.1 Acetone(WarningExtremely flammable. Use ad-equate ventilation.)7.2 Isopentane(WarningExtremely flammable. Avoidbuild up of vapors and remo
24、ve all sources of ignition, espe-cially non-explosion proof electrical apparatus.)7.3 Chromic Acid (Potassium Dichromate/Conc. SulfuricAcid)(WarningCauses severe burns. A recognized car-cinogen. Do not get in eyes, on skin or clothing.)FIG. 1 Bingham-Type PycnometerMetric Equivalentsin. mm in. mm in
25、. mm in. mm18 3.258 15.9 114 31.8 4 10214 6.434 19.1 1716 36.5 434 121716 11.1 1132 26.2 178 47.6 538 13612 12.7 118 28.6 2 50.8 638 162714 184NOTECover shields with mica or insulating cement. Wind with No. 26gage Chromel “A” wire: Upper block 60 in. (1.52 m) (25.4V), lower block85 in. (2.16 m) (35.
26、0V) wound vertically. Cover with insulating tape orinsulating cement and connect heaters in series. Insulate shields fromstand with14-in. Transite.FIG. 2 Details of Thermal Shields for 30-mL Syringe and 25-mLPycnometerD148002e128. Preparation of Apparatus8.1 Clean the pycnometer thoroughly with hot
27、chromic acidcleaning solution by means of the assembly shown in Fig. 5(WarningSee 7.3.) Chromic acid solution is the mosteffective cleansing agent. However, surfactant cleansing fluidshave also been used successfully. Mount the apparatus firmlyand connect the trap to the vacuum. Warm the necessaryam
28、ount of cleaning acid in the beaker, place the pycnometer onthe ground joint, and evacuate by opening the stopcock tovacuum. Fill the pycnometer with acid by turning the stop-cock, and either repeat several times, or remove the filledpycnometer and allow it to stand for several hours at 50 to60C. Re
29、move the acid from the pycnometer by evacuation,empty the acid from the trap, and flush the pycnometer withdistilled water. Clean in this manner whenever the pycnometeris to be calibrated or whenever liquid fails to drain cleanly fromthe walls of the pycnometer or its capillary. Ordinarily, thepycno
30、meter may be cleaned between determinations by wash-ing with a suitable solvent, rinsing with pure, dry acetone,followed by isopentane, and vacuum drying. (WarningSee7.1 and 7.2.)8.2 Transfer the pycnometer to the cleaner assembly shownin Fig. 4, with vacuum line and trap attached to the side tubeas
31、 indicated. Place the pycnometer on the cleaner with theupper hypodermic needle extending upward into the pycnom-eter, and press the edge of the ground joint on the rubberstopper until the vacuum holds it in place. Draw out all theliquid or sample. Immerse the lower end of the hypodermictube in a su
32、itable solvent and draw 20 to 25 mL through thepycnometer. Leaving the pycnometer in place, draw air throughit until it is dry. Clean the hypodermic syringe with the sameapparatus.9. Calibration of Pycnometers9.1 Weigh the clean, dry pycnometer to 0.1 mg and recordthe weight.NOTE 3It is convenient t
33、o use the lightest of a set of pycnometers asa tare. For best results the treatment and environment of both pycnometerand tare should be identical for some time prior to weighing.9.2 With a syringe of suitable size, transfer freshly boiledand cooled distilled water to the pycnometer through the fill
34、ingneedle (Note 6). Avoid trapping air bubbles in the bulb orcapillary of the pycnometer, removing bubbles, as they form,with the syringe, when possible. Also remove any water abovethe calibration mark and dry the overflow chamber andcapillary with a cotton-fiber pipe cleaner or cotton swab whichhas
35、 been moistened slightly with acetone. Do not touch theplunger of the syringe or hypodermic needle with fingers asminute quantities of oil transferred this way would cause faultydrainage in the capillary neck of the pycnometer.FIG. 3 Accessories for Bingham-Type PycnometerD148002e139.3 Close the pyc
36、nometer with the glass stopper and im-merse it to a point above the calibration mark in the constant-temperature bath adjusted to a constancy of 60.01C at thedesired temperature (Note 4). Periodically, or before the liquidexpands into the overflow chamber, remove the stopper, raisethe pycnometer suf
37、ficiently to expose the calibration mark toview, and readjust the liquid level to the mark by withdrawingliquid through the steel draw-off needle until expansion hasFIG. 4 Cleaner Assembly for Bingham-Type PycnometerFIG. 5 All-Glass Pycnometer Cleaner Assembly for Use with Hot Chromic Acid Cleaning
38、SolutionD148002e14stopped, indicating that the liquid has reached the temperatureof the thermostat. To minimize errors caused by faulty drain-age, do not allow the liquid to expand more than 10 mm abovethe calibration mark at any time. Allow the contents toequilibrate an additional 10 min and draw t
39、he level downexactly to the calibration line, avoiding parallax and using amagnifier, if necessary, to obtain good visibility. Remove anyliquid adhering to the walls above the calibration mark, withthe draw-off needle or pipe cleaner, depending upon thevolatility of the sample. Portions in the overf
40、low bulb can beremoved with a cotton swab moistened with acetone.NOTE 4For temperatures above 80C calculate the volume from thecoefficient of expansion of the glass observed from calibrations made at60, 70, and 80C.9.4 Replace the glass stopper, remove the pycnometer fromthe bath, wash the outside s
41、urface with acetone, and drythoroughly with a chemically clean, lint-free, slightly dampcloth. Place the pycnometer in or near the balance case for 20min and weigh to the nearest 0.1 mg.NOTE 5In atmospheres of low humidity (60 % or lower), drying thepycnometer by rubbing with a dry cotton cloth will
42、 induce static chargesequivalent to a loss of about 1 mg in the weight of the pycnometer. Thischarge may not be completely dissipated in less than 30 min. The use ofabout 0.1 mg of radium bromide- or polonium-coated foil in the balancecase, or maintaining the relative humidity at 60 percent or highe
43、r, aids inreducing weighing difficulties due to static charges.9.5 Calculate the pycnometer calibration factor, Ft, from theequation:Ft5density of water at tC!/weight of water in pycnometer at tC! (1)See Table 2 for the density of water between 0 and 100C.9.6 Duplicate determinations should not show
44、 a variationgreater than 60.2 mg in the net weight of the water in thepycnometer.10. Procedure for Viscous Liquids10.1 Weigh the pycnometer as directed in Section 8.10.2 Warm, in an oven or convenient warming chamber, thepycnometer, syringe with needle, and sample to a convenientworking temperature
45、consistent with the fluidity and volatilityof sample. Draw the requisite amount of sample into thesyringe and immediately fill the warmed pycnometer takingcare to avoid occluding air bubbles in the pycnometer bulb orcapillary. Continue the addition of sample, withdrawing thefilling needle gradually
46、so that the tip remains immersed in thesample, until the sample has been added to a depth of 10 or 20mm in the expansion chamber above the capillary, dependingupon the amount of contraction expected.10.3 Immerse the pycnometer bulb in the constant-temperature bath. As the sample contracts continue s
47、ampleaddition before the level recedes into the capillary or until asufficient amount has been added to maintain the meniscusslightly above the calibration mark at the reference tempera-ture. Allow to equilibrate to reference temperature.NOTE 6Equilibration time depends upon the viscosity and temper
48、a-ture of the sample at the time of filling. Usually this is three to four timesthat required for a fluid sample. A safe criterion is to allow 15 min moreequilibration time after the meniscus remains stationary.10.4 Remove excess sample with the 16-gage needle at-tached to a vacuum line, warming the
49、 needle if necessary.Swab the capillary above the calibration mark and the overflowchamber several times with a pipe cleaner or small cotton swabslightly moistened with a suitable solvent. Follow with a dryswab. Final adjustment to the mark may be done by picking outsample with a small probe, splinter, or wire.10.5 Remove the pycnometer from the bath, wash the outersurface with a suitable solvent followed by acetone and drythoroughly with a clean, lint-free, slightly damp cloth. Observethe same cleaning procedure as used in calib
