1、Designation: D1015 05 (Reapproved 2015)Standard Test Method forFreezing Points of High-Purity Hydrocarbons1This standard is issued under the fixed designation D1015; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last
2、revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers a procedure for the precisemeasurement of the freezing points of high-purity hydrocar-bons.1.2 The
3、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 appro-priate saf
4、ety 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 usedfor the sampling
5、 and determination of purity of certain specificcompounds, see Test Method D1016.2. Referenced Documents2.1 ASTM Standards:2D1016 Test Method for Purity of Hydrocarbons from Freez-ing PointsD1265 Practice for Sampling Liquefied Petroleum (LP)Gases, Manual MethodD4057 Practice for Manual Sampling of
6、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 conjunction with th
7、e physical constants for the hydro-carbons listed in Test Method D1016, 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 asreagent chemicals or
8、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 mechanism, suitable
9、 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 in the space betwee
10、n 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 liquefied oxygen evaporates
11、within thesealed space.)5.2 Resistance Bridge,6Mueller type, reading from0.0001 to 50 , in steps of 0.001 .1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.04.0D on Physical and Ch
12、emical Methods.Current edition approved June 1, 2015. Published July 2015. Originally approvedin 1949. Last previous edition approved in 2010 as D1015 05 (2010). DOI:10.1520/D1015-05R15.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceas
13、tm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe 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,” Journa
14、l of Research, JNBAA, National Institute of Standards andTechnology, Vol 35, No. 6, 1945, p. 355.4The sole source 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 t
15、oASTM International Headquarters. Your comments will receive careful consider-ation at a meeting of the responsible technical committee,1which you may attend.6Apparatus described in 5.2, 5.3, 5.4, and 5.5 was manufactured by the Leedsand Northrup Co., Philadelphia, PA, under the following catalog nu
16、mbers: 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 the lampand scale, No. 2100, are still available fr
17、om 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, and thegalvanometer, highest precision, No. 2284-
18、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.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, W
19、est Conshohocken, PA 19428-2959. United States1ABracket for motor, with rubber pad. QCeramic (or glass) fiber collar.BMotor, 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 us
20、ed, the metal shield must be provided withsuitable openings in sides and bottom (see 5.1). If liquid air is used, the 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 ins
21、ide diameter, 101 mm (4 in.);approximate inside depth, 330 mm (13 in.).DWheel. (See Fig. 3). TCeramic (or glass) fiber 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,
22、 XSpherical joint, 18/7.IAdjustable clamp holder. YStandard metal (copper or brass) to glass taper connections soldered.JClamp for freezing tube. ZConnection to vacuum pump.KStirrer. (See Fig. 3). aAnhydrous calcium sulfate, with indicator.LThermometer. bAnhydrous magnesium perchlorate, granular.MTu
23、be for inlet of dry air, with 12/5 spherical joint. dSeparating layer of glass wool.M12/5 spherical joint connection 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.
24、PStopcock on freezing tube. hTo source of compressed air.PStopcock (high vacuum) to drying tube. iFlow meter, for rates of 10 mL min to 20 mL min.P9Stopcock (high vacuum) to vacuum line.FIG. 1 Assembly of the Freezing-Point ApparatusD1015 05 (2015)25.3 Platinum Resistance Thermometer ,6precision gra
25、de,with a resistance near 25.5 at 0 C, calibrated by theNational Institute of Standards and Technology for the rangefrom 190 C to 500 C.5.4 Null Point Indicator, may be either a galvanometer or amicrovolt ammeter.5.4.1 Galvanometer,6having a sensitivity of 0.1 mVm at1 m for highest precision or a se
26、nsitivity of 0.5 mVm at 1 mfor routine precision.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 o
27、f 0.133 Pa in 10 minor less.5.8 Seeding Apparatus, 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 D1016.6. Materials6.1 Carbon Dioxide RefrigerantSolid
28、carbon dioxide in asuitable liquid. (WarningExtremely cold (78.5 C). 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 i
29、f in-haled. High concentrations can cause unconsciousness 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
30、 freezing, or both. Vapors can reactviolently with 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 impera
31、tivethat any glass vessel containing hydrocarbon 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 vio
32、lentexplosion. If liquid nitrogen is used as a refrigerant, nohydrocarbon sample should ever be permitted to cool below thecondensation temperature of oxygen (183 C 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
33、 Silica Gel, for use in silica gel funnel.5,9If the gel hasbeen exposed to the atmosphere because of punctured orloosely sealed containers, before use, dry the gel in a shallowvessel at 150 C to 205 C for 3 h, then transfer while hot to anair-tight container.7. Sampling7.1 Sampling from Bulk Storage
34、:7.1.1 CylinderRefer to Practice D1265 for instructions onintroducing samples into a cylinder from bulk storage.7.1.2 Open ContainersRefer to Practice D4057 for in-structions on introducing samples into open-type containersfrom bulk storage.7The sole source of supply of the apparatus known to the co
35、mmittee 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 the committee at this timeis Davison Chem
36、ical 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.ESpherical joint, 18/7.FIG. 2 Details of the Fr
37、eezing TubeD1015 05 (2015)3AStainless 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 position is 19.05 mm (34 in.) from center
38、.FSteel rod.GSet screws.HBrass coupling.ISteel shaft.JSteel rod, round.JSteel 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.) diameter nichrome wire downwards o
39、n a cylinder 14.3 mm (916 in.) in outside diam-eter 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 two endssilver soldered together.RPlace where shaft of the double helical stirrer is joined to the stirrer shaft.Metr
40、ic Equivalentsmmin.0.79413211.9115324.76331624151674.6122151677.837169.533822.237828.611860.33238117.54586.41457.1521410841463.5212114.3412215.98812FIG. 3 Details of the Stirring Assembly and SupportsD1015 05 (2015)48. Calibration of Thermometric System and Conversionof Resistance Readings to Temper
41、ature8.1 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 ThermometerThe platin
42、um-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 C to 500 C,
43、namely, R0, C, , and . If the thermometer has been properlyconstructed and annealed, the certified constants C, , and will not change significantly with time, but the value of R0maychange slightly.NOTE 2International Practical Temperature Scale (IPTS)In 1968, anew IPTS was adopted, replacing the pre
44、vious 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 T68T48vary. Above 10
45、0 C the differencesare plus; below 100 C they may be either plus or minus.If the measured freezing point is to be used for the determination ofpurity according to Test Method D1016, the measured freezing point tf,and the freezing point of the pure material tfo, should be on the sametemperature scale
46、. The values of tfogiven in Test Method D1016 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 Checking of the Ice
47、 PointFrequent measurements (atleast once every month) should be made of the resistance of thegiven platinum thermometer at the ice point, 0 C, as measuredon the given resistance bridge.10This value should differ onlyslightly from the certified value of R0. If the differencebecomes appreciable (appr
48、oaching 0.001 ), 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 substanceshaving freezing
49、 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 C to+50 C and +50 C to 290 C, with differences between suc-cessive unit degrees tabulated for linear interpolation (which ispermissible), may be easily placed on a single 300 mm by400 mm (14 in. by 16 in.) sheet
