1、Designation: D1217 12D1217 15Standard Test Method forDensity and Relative Density (Specific Gravity) of Liquids byBingham Pycnometer1This standard is issued under the fixed designation D1217; the number immediately following the designation indicates the year oforiginal adoption or, in the case of r
2、evision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S. Department of Defense.1. Scope*1.1 This test
3、method covers the measurement of the density of pure hydrocarbons or petroleum distillates boiling between9090 C and 110C110 C that can be handled in a normal fashion as a liquid at the specified test temperatures of 2020 C and25C.25 C.1.2 This test method provides a calculation procedure for the co
4、nversion of density to relative density (specific gravity).1.3 WARNINGMercury has been designated by many regulatory agencies as a hazardous material that can cause centralnervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Cautionsh
5、ould be taken when handling mercury and mercury containing products. See the applicable product Material Safety Data Sheet(MSDS) for details and EPAs websitehttp:/www.epa.gov/mercury/faq.htmfor additional information. Users should be awarethat selling mercury and/or mercury containing products intoi
6、n your state or country may be prohibited by law.1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsi
7、bilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. Specific warning statements are given in Section 7.2. Referenced Documents2.1 ASTM Standards:2D4052 Test Method for Density, Relative Density
8、, and API Gravity of Liquids by Digital Density MeterE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 density, nmass per unit volume at a specified temperature. D40523.1.2 relative density, nthe ratio of the density of a material at a stated temperature to th
9、e density of water at a statedtemperature. D40524. Summary of Test Method4.1 The liquid sample is introduced into a pycnometer, equilibrated to the desired temperature, and weighed. The relativedensity (specific gravity) or density is then calculated from this weight and the previously determined we
10、ight of water that isrequired to fill the pycnometer at the same temperature, both weights being corrected for the buoyancy of air.5. Significance and Use5.1 Density is a fundamental physical property which can be used in conjunction with other properties to characterize purehydrocarbons and their m
11、ixtures.1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.04.0D on Physical and Chemical Methods.Current edition approved Nov. 1, 2012Dec. 1, 2015. Published December 2012February
12、2016. Originally approved in 1952. Last previous edition approved in 20072012as D121793(2007).D1217 12. DOI: 10.1520/D1217-12.10.1520/D1217-15.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvol
13、ume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adeq
14、uately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM
15、International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States15.2 This test method was originally developed for the determination of the density of the ASTM Knock Test Reference Fuelsn-heptane and isooctane, with an accuracy of 0.00003 g/mL. Although it is no lon
16、ger employed extensively for this purpose, thistest method is useful whenever accurate densities of pure hydrocarbons or petroleum fractions with boiling points between 9090 Cand 110C110 C are required.6. Apparatus6.1 Pycnometer, Bingham-type,3 conforming to the dimensions given in Fig. 1, construct
17、ed of borosilicate glass, and having atotal weight not exceeding 30 g.6.2 Constant-Temperature Bath, provided with suitable pycnometer holders or clips and means for maintaining temperaturesconstant to 60.01C60.01 C in the desired range.6.3 Bath Thermometer, graduated in 0.1C0.1 C subdivisions and s
18、tandardized for the ice point and the range of use to thenearest 0.01C.0.01 C. ASTM Saybolt Viscosity Thermometer 17C as prescribed in Specification E1, designed for tests at21.1C21.1 C and 25C,25 C, is recommended.Astandardized platinum resistance thermometer may also be used, and offers thebest me
19、ans for observing minute temperature changes in the bath. Whichever means are available, it must be realized that for mosthydrocarbons the density coefficient is about 0.0008 units/C, and therefore an error of 60.013C60.013 C would cause an errorof 60.00001 in density.6.4 Hypodermic Syringe, 30-mL30
20、 mL capacity, of chemically resistant glass, equipped with a 152-mm152 mm needle madeof stainless steel tubing as shown in Fig. 2.6.5 Draw-Off Needle, made of stainless steel tubing as shown in Fig. 2.6.6 Solvent-Cleaning Assembly, as shown in Fig. 3.6.7 Chromic Acid Cleaning Apparatus, similar to t
21、hat shown in Fig. 4.3 The sole source of supply of the pycnometer known to the committee at this time is Reliance Glass Co., 220 Gateway Rd., Bensenville, IL 60106-0825. If you are awareof alternative suppliers, please provide this information toASTM International Headquarters.Your comments will rec
22、eive careful consideration at a meeting of the responsibletechnical committee,1 which you may attend.FIG. 1 Bingham-Type Pycnometer, 25 mLD1217 1526.8 Balance, capable of reproducing weighings within 0.1 mg. 0.1 mg. Mechanical balances should have sensitivity whichcauses the pointer to be deflected
23、2 or 3 scale divisions per 1 mg 1 mg when carrying a load of 30 g or less on each pan.The balanceshould be located in a room shielded from drafts and fumes and in which the temperature changes between related weighings(empty and filled pycnometer) do not cause a significant change in the ratio of th
24、e balance arms. Otherwise weighings shall bemade by the method of substitution, in which the calibrated weights and pycnometer are alternately weighed on the same balancepan. The same balance shall be used for all related weighings.6.9 Weights, whose relative values are known to the nearest 0.05 mg
25、or better. The same set of weights shall be used for thecalibration of the pycnometer and the determination of densities.FIG. 2 Accessories for Bingham-Type PycnometerFIG. 3 Cleaner Assembly for Bingham-Type PycnometerD1217 1537. Reagents and Materials7.1 Acetone(WarningExtremely flammable. Use adeq
26、uate ventilation.)7.2 Isopentane( WarningExtremely flammable. Avoid buildup of vapors and remove all sources of ignition, especiallynon-explosion proof electrical apparatus.)7.3 Chromic Acid (Potassium Dichromate/Conc. Sulfuric Acid)(WarningCauses severe burns. A recognized carcinogen.Do not get in
27、eyes, or on skin or clothing.)8. Preparation of Apparatus8.1 Thoroughly clean the pycnometer with hot chromic acid cleaning solution by means of the assembly shown in Fig. 4.Chromic acid solution (WarningSee 7.3) is the most effective cleaning agent. However, surfactant cleaning fluids have also bee
28、nused successfully. Mount the apparatus firmly and connect the trap to the vacuum. Warm the necessary amount of cleaning acidin the beaker, place the pycnometer on the ground joint, and evacuate by opening the stopcock to vacuum. Fill the pycnometer withacid by turning the stopcock, repeat several t
29、imes or remove the filled pycnometer, and allow it to stand for several hours at 50to 60C. 50 C to 60 C. Remove the acid from the pycnometer by evacuation, empty the acid from the trap, and flush thepycnometer with water. Cleaning should be made in this manner whenever the pycnometer is to be calibr
30、ated or whenever liquidfails to drain cleanly from the walls of the pycnometer or its capillary. Ordinarily, the pycnometer may be cleaned betweendeterminations by washing with a suitable solvent, rinsing with pure, dry acetone, followed by isopentane, and vacuum drying.8.2 Transfer the pycnometer t
31、o the cleaner assembly shown in Fig. 3, with vacuum line and trap attached to the side tube asindicated. Place the pycnometer on the cleaner with the upper hypodermic needle extending upward into the pycnometer, and pressthe edge of the ground joint on the rubber stopper until the vacuum holds it in
32、 place. Draw out all the liquid or sample. Immersethe lower end of the hypodermic tube in a suitable solvent and draw 20 to 25 mL to 25 mL through the pycnometer. Leaving thepycnometer in place, draw air through it until it is dry. Clean the hypodermic syringe with the same apparatus.9. Calibration
33、of Pycnometer9.1 Proceeding as directed in Section 10, determine the weight of freshly-boiled and cooled distilled water (distilled fromalkaline permanganate through a tin condenser) held by the pycnometer when equilibrated to volume at the bath temperature tobe used in the determination. Repeat unt
34、il at least three values agree to 60.2 mg.10. Procedure10.1 Using another 25-mL25 mL pycnometer as a tare (Note 1), weigh the clean, dry pycnometer to 0.1 mg and record theweight.NOTE 1It is convenient to use the lightest of a set of pycnometers as a tare. For best results the treatment and environm
35、ent of both pycnometer andtare should be identical for some time prior to weighing.10.2 Cool the sample to 5 to 10C 5 C to 10 C below the test temperature, and fill the clean 30-mL30 mLhypodermic syringe.Transfer the sample to the pycnometer through the filling needle; avoid trapping air bubbles (Wa
36、rningExtremely flammable.Avoid buildup of vapors and remove all sources of ignition, especially non-explosion proof electrical apparatus) in the bulb orcapillary of the pycnometer. If any are present, draw them into the syringe where possible. Also remove with the syringe ordraw-off needle any liqui
37、d above the calibration mark in the capillary or overflow reservoir. Dry the remainder with a cotton fiberpipe cleaner or cotton swab which has been dampened slightly with acetone.FIG. 4 All-Glass Pycnometer Cleaner Assembly for Use with Hot Chromic Acid Cleaning SolutionD1217 154NOTE 2For work of h
38、ighest accuracy on pure compounds, dissolved air may be removed from the sample by repeated freezing and remelting of thesample under vacuum in the pycnometer.10.3 Close the pycnometer with the glass stopper and immerse it to a point above the calibration mark in the constant-temperature bath adjust
39、ed to a constancy of 60.01C60.01 C at the desired temperature. Periodically, or before the liquidexpands into the overflow chamber, remove the stopper, raise the pycnometer sufficiently to expose the calibration mark to view,and readjust the liquid level to the mark by withdrawing liquid through the
40、 steel draw-off needle until expansion has stopped,indicating that the liquid has reached the temperature of the thermostat. Do not allow the liquid to expand more than 10 mm abovethe calibration mark at any time, to minimize errors caused by faulty drainage. Allow the contents to equilibrate an add
41、itional 10min and draw the level down exactly to the calibration line, avoiding parallax and using a magnifier, if necessary, to obtain goodvisibility. Remove any liquid adhering to the walls above the calibration mark, with the draw-off needle or pipe cleaner, dependingupon the volatility of the sa
42、mple. Portions in the overflow bulb may be removed with a cotton swab moistened with acetone.10.4 Replace the glass stopper, remove the pycnometer from the bath, wash the outside surface with acetone, and dry thoroughlywith a chemically clean, lint-free, slightly damp cloth. Place the pycnometer in
43、or near the balance case for 20 min 20 min andweigh to the nearest 0.1 mg. 0.1 mg. In atmospheres of low humidity (60 % or lower), drying the pycnometer by rubbing with adry cotton cloth will induce static charges equivalent to a loss of about 1 mg in the weight of the pycnometer. This charge needno
44、t be completely dissipated in less than 30 min. 30 min. The use of about 0.1-mg 0.1 mg radium bromide- or polonium-coatedfoil in the balance case, or maintaining the relative humidity at 60 % or higher, aids in reducing weighing difficulties due to staticcharges.10.5 Record temperature of the balanc
45、e, barometric pressure, and relative humidity.11. Calculation11.1 Calculate the true density of the sample as follows:Density,g/mL at C5Ws11da/ds!2da/dwt!dw/Ww11da/dw!2da/dwt! (1)where:Ws = weight in air of sample contained in the pycnometer at the test temperature, g,Ww = weight in air of the water
46、 contained in the pycnometer at the calibration temperature, g,dw = density of water at the calibration temperature, as obtained from Table 1,da = density of air in balance case at the time of weighing, as calculated from 10.3,dwt = density of weights used in weighing the sample and water (brass = 1
47、0.4 g/mL, stainless steel = 7.75 g/mL), anddwt = density of weights used in weighing the sample and water (brass = 10.4 g/mL, stainless steel = 7.75 gmL), andds = approximate density of sample orWs3d!/Ww (2)11.2 The equation assumes that the weighings of the pycnometer empty and filled are made in s
48、uch a short time interval thatthe air density has not changed. If significant change should occur, the calculated apparent weight of the sample, Ws, in thisequation, must be corrected for the difference in air buoyancy exerted on the pycnometer as follows:Ws5W2PS2Wp11da/2.2! (3)2da/dwt!)/11da2/2.2!2
49、da2/dwt!where:W2PS = weight of pycnometer and contained sample under second or final air density,WP = weight of pycnometer in air of first density,da = density of air when weighing empty pycnometer,da 2 = density of air when weighing filled pycnometer,dwt = density of weights, and2.2 = borosilicate glass.Likewise, if the pycnometer, empty and filled with water for calibration, is weighed under different air densities a similarcorrection for different air buoyancies shall be applied.11.3 Calculate the relati
