1、Designation: D 1480 07An 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 oforigi
2、nal 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.1. Scope*1.1 This test method covers two procedures for the mea-surement of
3、 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 viscositiesbelow 40 000 cSt (mm2/s) at the test temperature. The methodis designed for use at any temperature between 20 and 100C.It can b
4、e 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 temperatures, see Test Method D 1217.1.2 This test method provides a calculation procedure forconverting density to specific gravity.1
5、.3 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.4 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appr
6、o-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 1217 Test Method for Density and Relative Density(Specific Gravity) of Liquids by Bingham PycnometerE1 Specification for ASTM Liquid-in-Glass Ther
7、mometers3. 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 relative density (specific gravity)the ratio of themass (weight in a vacuum) of a given volume of material at atemperature, t1, to the mass of
8、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 referencetemperature is 4C (the temperature at which the relativedensity of water is unity), relative density (specific gravity) anddensity are numeri
9、cally equal.4. Summary of Test Method4.1 The liquid sample is introduced into the pycnometer,equilibrated to the desired temperature, and weighed. Thedensity or specific gravity is then calculated from this weightand the previously determined calibration factor, and a correc-tion is applied for the
10、buoyancy of air.5. Significance and Use5.1 Density is a fundamental physical property that can beused in conjunction with other properties to characterize boththe light and heavy fractions of petroleum and to assess thequality of crude oils.5.2 Determination of the density or relative density ofpetr
11、oleum 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 elevated tempera-tures of 40 and 100C is particularly useful in providing thedata needed for the conversion of kinematic viscosities incen
12、tistokes (mm2/s) to the corresponding dynamic viscositiesin centipoises (mPas).6. Apparatus6.1 Pycnometer,3Bingham-type of 10-mL capacity (asshown in Fig. 1), constructed of heat-resistant4glass.NOTE 2Pycnometers having capacities of 2 to 25 mLare available buthave not been cooperatively evaluated.6
13、.2 Constant-Temperature Bath, provided with suitable py-cnometer holders and means for maintaining temperaturesconstant to 60.01C in the desired range. Water-glycerinmixtures can be used for temperatures up to 100C.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Product
14、s and Lubricants and is the direct responsibility of SubcommitteeD02.04.0D on Physical and Chemical Methods.Current edition approved Dec. 1, 2007. Published January 2008. Originallyapproved in 1957. Last previous edition approved in 2002 as D 148002e1.2For referenced ASTM standards, visit the ASTM w
15、ebsite, 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.3There is more than one supplier. If you cannot find a supplier, then contactSubcommittee D02.04.0D on Physic
16、al and Chemical Methods for possible suppli-ers.4Borosilicate glass has been found satisfactory for this purpose.1*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.6.3 Ba
17、th Thermometer, graduated in 0.1C subdivisions andstandardized for the range of 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 there
18、fore an error of 60.013C would cause anerror of 60.00001 in density. A standardized platinum resis-tance thermometer may also be used, and it offers the bestmeans for observing temperature changes in the bath.6.4 Thermal Shields, as shown in Fig. 2, to hold thepycnometer and syringe during the filli
19、ng 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” wire, insulated from theshields with mica, covered with insulating tape, and ha
20、vingresistances 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 that the center of the wells may bealigned, and the upper shield raised 180 to 200
21、 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-off Needle, made of stainless-steel tubing, asshown in Fig. 3.6.7 Solvent Clean
22、ing 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 a room shielded from drafts and fumes and in which thetemperature changes betwe
23、en 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 to thenearest 0.05 mg or better. Use the same set of weights for thecalibration o
24、f 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 remove all sources of ignition, espe-cially non-explosion proof electrical apparatus
25、.)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. mm in. mm18 3.258 15.9 114 31.8 4 10214 6.434 19.1 1716 36.5 434 121716 11.1 1
26、132 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) (35.0V) wound vertically. Cover with insulating tape orinsulating cement and connect
27、 heaters in series. Insulate shields fromstand with14-in. Transite.FIG. 2 Details of Thermal Shields for 30-mL Syringe and 25-mLPycnometerD14800728. Preparation of Apparatus8.1 Clean the pycnometer thoroughly with hot chromic acidcleaning solution by means of the assembly shown in Fig. 5(WarningSee
28、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 necessaryamount of cleaning acid in the beaker, place the pycnometer onthe ground joint, and
29、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. Remove the acid from the pycnometer by evacuation,empty the acid from the trap, and
30、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, thepycnometer may be cleaned between determinations by wash-ing with a suitable solvent, r
31、insing 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 indicated. Place the pycnometer on the cleaner with theupper hypodermic needle ex
32、tending 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 suitable solvent and draw 20 to 25 mL through thepycnometer. Leaving the pycnometer
33、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 to use the lightest of a set of pycnometers asa tare. For best results the treatmen
34、t 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 fillingneedle (Note 6). Avoid trapping air bubbles in the bulb orcapillary of the pycn
35、ometer, 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 been moistened slightly with acetone. Do not touch theplunger of the syringe or h
36、ypodermic 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 PycnometerD14800739.3 Close the pycnometer with the glass stopper and im-merse it to a point above the calibration mark
37、 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 sufficiently to expose the calibration mark toview, and readjust the liquid level to th
38、e 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 SolutionD1480074stopped, indicating that the liquid has reached the temperatureof th
39、e 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 the level downexactly to the calibration line, avoiding parallax and using amagnifier,
40、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 overflow bulb can beremoved with a cotton swab moistened with acetone.NOTE 4For temperature
41、s 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 surface with acetone, and drythoroughly with a chemically clean, lint-free, slightly da
42、mpcloth. 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 induce static chargesequivalent to a loss of about 1 mg in the weight of the pycnomet
43、er. 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 higher, aids inreducing weighing difficulties due to static charges.9.5 Calculate the pycno
44、meter 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 a variationgreater than 60.2 mg in the net weight of the water in thepycnometer.10. P
45、rocedure 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 consistent with the fluidity and volatilityof sample. Draw the requisite amount of sam
46、ple 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 so that the tip remains immersed in thesample, until the sample has been added to a de
47、pth 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 sampleaddition before the level recedes into the capillary or until asufficient amount
48、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 tempera-ture of the sample at the time of filling. Usually this is three to four timesthat r
49、equired 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 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 Remov
