1、Designation: D 1015 05An American National StandardStandard Test Method forFreezing Points of High-Purity Hydrocarbons1This standard is issued under the fixed designation D 1015; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the
2、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 a procedure for the precisemeasurement of the freezing points of high-purity hydroca
3、r-bons.1.2 The values stated in SI units are to be regarded as thestandard. The values in parentheses are for information only.1.3 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 a
4、ppro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specific hazardstatements, see 5.1, 6.1 and 6.2.NOTE 1For the calculation of the molal purity of essentially purecompounds from measured freezing points and for procedures to be usedf
5、or the sampling and determination of purity of certain specific com-pounds, see Test Method D 1016.2. Referenced Documents2.1 ASTM Standards:2D 1016 Test Method for Purity of Hydrocarbons fromFreezing PointsD 1265 Practice for Sampling Liquefied Petroleum (LP)Gases (Manual Method)D 4057 Practice for
6、 Manual Sampling of Petroleum andPetroleum Products3. Summary of Test Method3.1 The precise experimental measurement of the freezingpoint is made from interpretation of time-temperature freezingor melting curves.34. Significance and Use4.1 The freezing point measured by this test method, whenused in
7、 conjunction with the physical constants for the hydro-carbons listed inTest Method D 1016, allows the determinationof the purity of the material under test. A knowledge of thepurity of these hydrocarbons is often needed to help controltheir manufacture and to determine their suitability for use asr
8、eagent chemicals or for conversion to other chemical inter-mediates or finished products.5. Apparatus5.1 Freezing-Point Apparatus,4,5as shown in Figs. 1-3comprising a freezing tube, a metal sheath for the freezingtube, a Dewar flask for the cooling bath, a Dewar flask for thewarming bath, a stirring
9、 mechanism, suitable clamps andholders for the parts, and the absorption tubes. The outer wallsof all Dewar flasks can be covered with adhesive tape tominimize danger from glass in case of breakage. (WarningWhen using liquid nitrogen as a refrigerant, provide a means toprevent condensation of oxygen
10、 in the space between thefreezing tube and the metal sheath and subsequent sealing ofthe space by ice forming on the ceramic (or glass) fiber collar.Provide the metal sheath with suitable openings in the sidesand bottom. Failure to do this may result in breakage of thefreezing tube when the liquefie
11、d oxygen evaporates within thesealed space.)1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.04 on Hydrocarbon Analysis.Current edition approved Nov. 1, 2005. Published November 2005. Originallya
12、pproved in 1949. Last previous edition approved in 2004 as D 101599(2004).2For referenced 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
13、ASTM website.3For details not given here, see Glasgow, A. R., Jr., Rossini, F. D., and Streiff,A. J., “Determination of the Purity of Hydrocarbons by Measurement of FreezingPoints,” Journal of Research, JNBAA, National Institute of Standards and Tech-nology, Vol 35, No. 6, 1945, p. 355.4The sole sou
14、rce of supply of the apparatus known to the committee at this timeis Reliance Glass Works, Inc., Bensenville, IL.5If you are aware of alternative suppliers, please provide this information toASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the respon
15、sible technical committee,1which you may attend.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.ABracket for motor, with rubber pad. QCeramic (or glass) fiber collar.B
16、Motor, with reduction gears, to give 120 r/min. RBrass cylinder, 317.5 mm (1212 in.) in length and 54 mm (218 in.) in inside diameter,with bakelite collar; when liquid nitrogen is used, the metal shield must be provided withsuitable openings in sides and bottom (see 5.1). If liquid air is used, the
17、metal shield shouldbe constructed so as to keep hydrocarbon from contact with liquid air (see 6.2).CCoupling. (See Fig. 3). SDewar flask, for cooling or warming bath; approximate inside diameter, 101 mm (4 in.);approximate inside depth, 330 mm (13 in.).DWheel. (See Fig. 3). TCeramic (or glass) fiber
18、 pad at bottom of cylinder R.ESteel rod. (See Fig. 3). UWood block support.FBearing. (See Fig. 3). VTable top.GSupport for bearing. (See Fig. 3). WWall.HSupport for freezing tube. X,X8Spherical joint, 18/7.IAdjustable clamp holder. YStandard metal (copper or brass) to glass taper connections soldere
19、d.JClamp for freezing tube. ZConnection to vacuum pump.KStirrer. (See Fig. 3). aAnhydrous calcium sulfate, with indicator.LThermometer. bAnhydrous magnesium perchlorate, granular.MTube for inlet of dry air, with 12/5 spherical joint. dSeparating layer of glass wool.M812/5 spherical joint connection
20、to rotameter. eAscarite.NCork stopper, with holes as shown, plus a small holefor the “seed” wire.fAnhydrous calcium sulfate.OFreezing tube, with silvered jacket. (See Fig. 2) gTo air.PStopcock on freezing tube. hTo source of compressed air.P8Stopcock (high vacuum) to drying tube. iFlow meter, for ra
21、tes of 10 to 20 mL/min.P9Stopcock (high vacuum) to vacuum line.FIG. 1 Assembly of the Freezing-Point ApparatusD10150525.2 Resistance Bridge,6Mueller type, reading from 0.0001to 50 V, in steps of 0.001 V.5.3 Platinum Resistance Thermometer,6precision grade,with a resistance near 25.5 V at 0C, calibra
22、ted by the NationalInstitute of Standards and Technology for the range from 190to 500C.5.4 Null Point Indicator, may be either a galvanometer or amicrovolt ammeter.5.4.1 Galvanometer,6having a sensitivity of 0.1 mV/m at 1m for highest precision or a sensitivity of 0.5 mV/m at 1 m forroutine precisio
23、n.5.4.2 Microvolt Ammeter.5,75.5 Lamp and Scale,6any suitable type.5.6 Stopwatch or Clock, preferably having graduations inminutes and hundredths of minutes.5.7 High-Vacuum Oil Pump,5,8capable of evacuating thejacket of the freezing tube to a pressure of 0.133 Pa in 10 minor less.5.8 Seeding Apparat
24、us, as shown in Fig. 4, for inducingcrystallization.5.9 Silica Gel Funnel, as shown in Fig. 5, for filteringcompounds through silica gel to remove water. To be used onlywhen specified in Test Method D 1016.6. Materials6.1 Carbon Dioxide RefrigerantSolid carbon dioxide in asuitable liquid. (WarningEx
25、tremely cold (78.5C). Liber-ates heavy gas which can cause suffocation. Contact with skincauses burns or freezing, or both. Vapors can react violentlywith hot magnesium or aluminum alloys.) Acetone is recom-mended. (WarningExtremely flammable. Harmful if in-haled. High concentrations can cause uncon
26、sciousness ordeath. Contact can cause skin irritation and dermatitis. Userefrigerant bath only with adequate ventilation.)6.2 Liquid Nitrogen or Liquid Air(WarningExtremelycold. Liberates gas which can cause suffocation. Contact withskin causes burns or freezing, or both. Vapors can reactviolently w
27、ith hot magnesium or aluminum alloys.) For use asa refrigerant. If obtainable, liquid nitrogen is preferable be-cause of its safety.6.2.1 Use liquid nitrogen refrigerant only with adequateventilation. If liquid air is used as a refrigerant, it is imperativethat any glass vessel containing hydrocarbo
28、n or other combus-tible compound and immersed in liquid air be protected with asuitable metal shield. The mixing of a hydrocarbon or othercombustible compound with liquid air due to the breaking of aglass container would almost certainly result in a violentexplosion. If liquid nitrogen is used as a
29、refrigerant, nohydrocarbon sample should ever be permitted to cool below thecondensation temperature of oxygen (183C at 1 atm). Thiswould not be likely to occur in normal operation, but mightoccur if the apparatus were left unattended for some time.6.3 Silica Gel, for use in silica gel funnel.5,9If
30、the gel hasbeen exposed to the atmosphere because of punctured orloosely sealed containers, before use, dry the gel in a shallowvessel at 150 to 205C for 3 h, then transfer while hot to anair-tight container.6Apparatus described in 5.2, 5.3, 5.4, and 5.5 was manufactured by the Leedsand Northrup Co.
31、, Philadelphia, PA, under the following catalog numbers: resistancebridge, No. 8069 B; platinum resistance thermometer, No. 8163 B; galvanometer,highest precision, No. 2284 D; galvanometer, routine precision, No. 2430 A; lampand scale, No. 2100. The galvanometer, routine precision, No. 2430-A, and t
32、he lampand scale, No. 2100, are still available from Leeds and Northrup. The platinumresistance thermometer, No. 8163-B, is no longer available from Leeds andNorthrup, but is available with the same part number from Yellows SpringsInstrument Co., Yellow Springs, OH. The resistance bridge No. 8069-B,
33、 and thegalvanometer, highest precision, No. 2284-D, are no longer available; however, theymay be obtainable from instrument exchanges or used equipment suppliers. If otheravailable instrumentation is substituted for the original, the precision statement ofSection 13 will not apply.7The sole source
34、of supply of the apparatus known to the committee at this timeis Keithley Instruments, Inc., 28775 Aurora Rd., Cleveland, OH.8The sole source of supply of the apparatus known to the committee at this timeis Boekel Industries, Inc. Philadelphia, PA.9The sole source of supply of the apparatus known to
35、 the committee at this timeis Davison Chemical Co., Baltimore, MD.AHigh-vacuum stopcock, hollow plug, oblique 312-mm bore.BInside opening of freezing tube, which must have no bulge at this point.CSlanted connection to jacket of freezing tube.DInternal walls of jacket of freezing tube, silvered.ESphe
36、rical joint, 18/7.FIG. 2 Details of the Freezing TubeD1015053AStainless steel rod, round.BGerman-silver tube.CPins.DHoles, 3.2 mm (18 in.) in diameter.EBrass wheel, with three holes; tapped for machine screws, spaced 12.7 mm (12 in.), 19.05 mm (34 in.), and 25.4 mm (1 in.) from center;normal positio
37、n is 19.05 mm (34 in.) from center.FSteel rod.GSet screws.HBrass coupling.ISteel shaft.JSteel rod, round.J8Steel rod, square.KConnecting pin.LBrass sleeve bearing.MSteel pipe, 12.7 mm (12 in.) nominal size.NBrass coupling.OBrass tee.PAluminum.QDouble helical stirrer, made by winding 1.6 mm (116 in.)
38、 diameter nichrome wire downwards on a cylinder 14.3 mm (916 in.) in outside di-ameter to form the inner helix, and then upwards over a cylinder 20.7 mm (1316 in.) in outside diameter to form the outer helix, with the twoends silver soldered together.RPlace where shaft of the double helical stirrer
39、is joined to the stirrer shaft.Metric Equivalentsmmin.0.79413211.9115324.76331624151674.6122151677.837169.533822.237828.611860.33238117.54586.41457.1521410841463.5212114.3412215.98812FIG. 3 Details of the Stirring Assembly and SupportsD10150547. Sampling7.1 Sampling from Bulk Storage:7.1.1 CylinderR
40、efer to Practice D 1265 for instructionson introducing samples into a cylinder from bulk storage.7.1.2 Open ContainersRefer to Practice D 4057 for in-structions on introducing samples into open-type containersfrom bulk storage.8. Calibration of Thermometric System and Conversionof Resistance Reading
41、s to Temperature8.1 Calibration of Resistance BridgeThe Mueller-typeresistance bridge should have its calibration checked at appro-priate intervals by measurement of a suitable external certifiedresistance, with intercomparison of the resistances of thebridge.8.2 Calibration of Resistance Thermomete
42、rThe platinum-resistance thermometer is provided with four calibration con-stants certified by the National Institute of Standards andTechnology for use in converting the resistance of the ther-mometer into temperature according to the International Tem-perature Scale, for use in the range from 190
43、to 500C,namely, R0, C, d, and b. If the thermometer has been properlyconstructed and annealed, the certified constants C, d, and bwill not change significantly with time, but the value of R0maychange slightly.NOTE 2International Practical Temperature Scale (IPTS)In 1968,a new IPTS was adopted, repla
44、cing the previous scale in use since 1948.The 1948 IPTS was based on the boiling point of oxygen, the sulfur point,ice point, and steam point. The 1968 IPTS is based on the triple point ofwater, tin point, zinc point, and boiling point of oxygen. The differencesin the two temperature scales T68T48va
45、ry. Above 100C the differencesare plus; below 100C they may be either plus or minus.If the measured freezing point is to be used for the determination ofpurity according to Test Method D 1016, the measured freezing point tf,and the freezing point of the pure material tfo, should be on the sametemper
46、ature scale. The values of tfogiven in Test Method D 1016 are onthe 1968 IPTS. Therefore, values of tfdetermined using thermometerscalibrated on the 1948 scale should be converted to their 1968 IPTSequivalent. This conversion can be made by applying the appropriatecorrection from Table 1.8.3 Checkin
47、g of the Ice PointFrequent measurements (atleast once every month) should be made of the resistance of thegiven platinum thermometer at the ice point, 0C, as measuredon the given resistance bridge.10This value should differ onlyslightly from the certified value of R0. If the differencebecomes apprec
48、iable (approaching 0.001 V), the calibration ofthe bridge should be checked. If the bridge has not changed, thechange has occurred in the thermometer, and a recalibration ofit is recommended.8.4 Conversion of Resistance Readings to TemperatureWhen determinations are made on a number of substanceshav
49、ing freezing points at different temperatures, time will besaved by making up a table giving values of the resistance, R,for each unit degree of temperature in the given range. Valuesof resistance for unit degrees, for the ranges from 190 to+50C and +50 to 290C, with differences between successiveunit degrees tabulated for linear interpolation (which is per-missible), may be easily placed on a single 300 by 400-mm (1410The ice point may be measured according to the
