1、Designation: D5482 07 (Reapproved 2013)Standard Test Method forVapor Pressure of Petroleum Products (Mini MethodAtmospheric)1This standard is issued under the fixed designation D5482; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision,
2、 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.1. Scope1.1 This test method covers a procedure for the determina-tion of total vapor pressure of petroleum products
3、usingautomatic vapor pressure instruments. The test method issuitable for testing samples with boiling points above 0C(32F) that exert a vapor pressure between 7 and 110 kPa (1.0and 16 psi) at 37.8C (100F) at a vapor-to-liquid ratio of 4:1.The test method is applicable to gasolines containing oxygen
4、-ates. No account is made of dissolved water in the sample.NOTE 1Because the external atmospheric pressure does not influencethe resultant vapor pressure, this vapor pressure is an absolute pressure at37.8C (100F) in kPa (psi). This vapor pressure differs from the truevapor pressure of the sample du
5、e to some small vaporization of the sampleand dissolved air into the air of the confined space.1.1.1 Some gasoline-oxygenate blends may show a hazewhen cooled to 0 to 1C. If a haze is observed in 8.5, it shallbe indicated in the reporting of results. The precision and biasstatements for hazy samples
6、 have not been determined (seeNote 6).1.2 This test method is a modification of Test MethodD5191 (Mini Method) in which the test chamber is at atmo-spheric pressure prior to sample injection.1.3 This test method covers the use of automated vaporpressure instruments that perform measurements on liqui
7、dsample sizes in the range from 1 to 10 mL.1.4 This test method is suitable for the determination of thedry vapor pressure equivalent (DVPE) of gasoline andgasoline-oxygenate blends by means of a correlation equation(see 13.2). The calculated DVPE is considered equivalent tothe result obtained on th
8、e same material when tested by TestMethod D4953.1.5 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibili
9、ty 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 specificwarning statements, see 7.2 through 7.7.)2. Referenced Documents2.1 ASTM Standards:2D4057 Practice for Manual Sampling of Petrol
10、eum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD4953 Test Method for Vapor Pressure of Gasoline andGasoline-Oxygenate Blends (Dry Method)D5190 Test Method for Vapor Pressure of Petroleum Prod-ucts (Automatic Method) (Withdrawn 2012)3D5191 Test Meth
11、od for Vapor Pressure of Petroleum Prod-ucts (Mini Method)3. Terminology3.1 Definitions:3.1.1 dry vapor pressure equivalent (DVPE), nvalue cal-culated by a defined correlation equation, that is expected to becomparable to the vapor pressure value obtained by TestMethod D4953, Procedure A.3.1.2 gasol
12、ine-oxygenate blend, nspark-ignition enginefuel consisting primarily of gasoline with one or more oxygen-ates.3.1.3 oxygenate, noxygen-containing ashless organiccompound, such as an alcohol or ether, which may be used asa fuel or fuel supplement. D41753.1.4 platinum resistance thermometer, n tempera
13、turemeasuring device with platinum wire, whose electrical resis-tance changes in relation to temperature.1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.08 on Volatility.Current edition approved
14、 June 1, 2013. Published August 2013. Originallyapproved in 1993. Last previous edition approved in 2007 as D5482 07. DOI:10.1520/D5482-07R13.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards vol
15、ume information, refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States13.1.5 total vapor pre
16、ssure, nobserved pressure measuredin the experiment, that is the sum of the partial pressure of thesample and the partial pressure of the dissolved air.3.1.6 vapor pressure, npressure exerted by the vapor of aliquid when in equilibrium with the liquid. D41753.2 Abbreviations:3.2.1 DVPE, ndry vapor p
17、ressure equivalent.3.2.2 MTBE, nmethyl t-butyl ether.4. Summary of Test Method4.1 A known volume of chilled, air-saturated sample isintroduced into a thermostatically controlled test chamber, theinternal volume of which is five times that of the total testspecimen introduced into the chamber. The te
18、st chamber is atatmospheric pressure prior to introduction of the sample. Afterintroduction of the sample into the test chamber, the testspecimen is allowed to reach thermal equilibrium at the testtemperature, 37.8C (100F). The resulting rise in pressure inthe chamber is measured using a pressure tr
19、ansducer sensorand indicator.4.2 The measured total vapor pressure is converted to aDVPE by use of a correlation equation (see 13.2).5. Significance and Use5.1 Vapor pressure is an important physical property ofvolatile liquids.5.2 Vapor pressure is critically important for both automo-tive and avia
20、tion gasolines, affecting starting, warm-up, andtendency to vapor lock with high operating temperatures orhigh altitudes. Maximum vapor pressure limits for gasoline arelegally mandated in some areas as a measure of air pollutioncontrol.6. Apparatus6.1 Vapor Pressure ApparatusThe type of apparatus4su
21、itable for use in this test method employs a small volume testchamber incorporating a transducer for pressure measurementsand associated equipment for thermostatically controlling thechamber temperature.6.1.1 The test chamber shall be designed to contain between2 and 50 mL of liquid and vapor and be
22、 capable of maintaininga vapor-liquid ratio between 3.95 and 1.00 and 4.05 and 1.00.6.1.2 The pressure transducer shall have a minimum opera-tional range from 0 to 172 kPa (0 to 25.0 psi) with a minimumresolution of 0.1 kPa (0.01 psi) and a minimum accuracy of60.3 kPa (60.05 psi). The pressure measu
23、rement system shallinclude associated electronics and readout devices to displaythe resulting pressure reading.6.1.3 A thermostatically controlled heater shall be used tomaintain the test chamber at 37.8 6 0.1C (100 6 0.2F) forthe duration of the test.6.1.4 A platinum resistance thermometer shall be
24、 used formeasuring the temperature of the test chamber. The minimumtemperature range of the measuring device shall be fromambient to 75C (167F) with a resolution of 0.1C (0.2F) andaccuracy of 0.1C (0.2F).6.1.5 The vapor pressure apparatus shall have provisions forintroduction of the test specimen in
25、to the test chamber and forthe cleaning or purging of the chamber following the test.6.2 Syringe, if required, gas tight, 1 to 20 mL capacity witha 61 %, or better, accuracy and a 61 %, or better, precision.The capacity of the syringe shall not exceed two times thevolume of the test specimen being d
26、ispensed, and shall bechosen so as to provide maximum accuracy and resolution forthe volume to be injected.6.3 Iced-Water Bath or Air Bath , for chilling the samplesand syringe to temperatures between 0 and 1C (32 and 34F).6.4 Pressure Measuring Device, capable of measuring am-bient and above ambien
27、t pressures with an accuracy of 0.20kPa (0.03 psi) or better at the same elevation relative to sealevel as the apparatus in the laboratory.6.4.1 When a mercury manometer is not used as thepressure measuring device, the calibration of the pressuremeasuring device employed shall be periodically checke
28、d(with traceability to a nationally recognized standard) to ensurethat the device remains within the required accuracy specifiedin 6.4.6.5 Pressure Source, clean, dry compressed gas or othersuitable compressed air capable of providing pressure forcalibration of the transducer and cleaning of the cel
29、l.NOTE 2Avacuum source is an alternate means for cleaning of the cell.7. Reagents and Materials7.1 Purity of ReagentsUse chemicals of at least 99 %purity for quality control checks (see Section 11). Unlessotherwise indicated, it is intended that all reagents conform tothe specifications of the Commi
30、ttee on Analytical Reagents ofthe American Chemical Society where such specifications areavailable.5Lower purities can be used, provided it is firstascertained that the reagent is of sufficient purity to permit itsuse without lessening the accuracy of the determination.7.2 Cyclohexane, (WarningCyclo
31、hexane is flammableand a health hazard).7.3 Cyclopentane, (WarningCyclopentane is flammableand a health hazard).7.4 2,2-Dimethylbutane, (Warning2,2-dimethylbutane isflammable and a health hazard).4The following instruments have been found satisfactory for use in this testprocedure as determined by i
32、nterlaboratory testing: Herzog Mini Reid VaporPressure Model MP970available from Varlen Instruments, Inc., 2777 WashingtonBlvd., Bellwood, IL 60104 and ABB Model 4100available from ABB ProcessAnalytics, Lewisburg, WV. If you are aware of alternative suppliers, please providethis information to ASTM
33、International Headquarters. Your comments will receivecareful consideration at a meeting of the responsible technical committee,1whichyou may attend.5Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For Suggestions on the testing of reagents notl
34、isted by the American Chemical Society, see Annual Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmacopeiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D5482 07 (2013)27.5 2,3-Dimethylbutane, (Warning2,3-dimethylbutane i
35、sflammable and a health hazard).7.6 2-Methylpentane, (Warning2-methylpentane is flam-mable and a health hazard).7.7 Toluene, (WarningToluene is flammable and a healthhazard).8. Sampling8.1 General Requirements:8.1.1 The extreme sensitivity of vapor pressure measure-ments to losses through evaporatio
36、n and the resulting changesin composition is such as to require the utmost precaution andthe most meticulous care in the handling of samples.8.1.2 Obtain a sample and test specimen in accordance with10.3 of Practice D4057, except do not use 10.3.1.8 of PracticeD4057, Sampling by Water Displacement,
37、for fuels containingoxygenates. Use a 1-L (1-qt) sized container filled between 70to 80 % with sample.8.1.3 Perform the vapor pressure determination on the firsttest specimen withdrawn from a sample container. Do not usethe remaining sample in the container for a second vaporpressure determination.
38、If a second determination is necessary,obtain a new sample.8.1.4 Protect samples from excessive temperatures prior totesting. This can be accomplished by storage in an appropriateice bath or refrigerator.8.1.5 Do not test samples stored in leaky containers. Discardand obtain a new sample if leaks ar
39、e detected.8.1.6 Do not store samples in plastic (polyethylene,polypropylene, and so forth) containers since volatile materialsmay diffuse through the walls of the container.8.2 Sampling TemperatureCool the sample container andcontents in an ice bath or refrigerator to the 0 to 1C (32 to34F) range p
40、rior to opening the sample container. Allowsufficient time to reach this temperature. Verify the sampletemperature by direct measurement of the temperature of asimilar liquid in a similar container placed in the cooling bathor refrigerator at the same time as the sample.8.3 Verification of Sample Co
41、ntainer FillingWith thesample at a temperature of 0 to 1C, take the container from thecooling bath or refrigerator and wipe dry with an absorbentmaterial. If the container is not transparent, unseal it and usinga suitable gage, confirm that the sample volume equals 70 to80 % of the container capacit
42、y (see Note 3). If the sample iscontained in a transparent glass container, verify that thecontainer is 70 to 80 % full by suitable means (see Note 3).8.3.1 Do not perform a vapor pressure test on the sample ifthe container is filled to less than 70 volume % of the containercapacity.8.3.2 If the con
43、tainer is more than 80 volume % full, pourout enough sample to bring the container contents within the 70to 80 volume % range. Do not return any sample to thecontainer once it has been withdrawn.NOTE 3For non-transparent containers, one way to confirm that thesample volume equals 70 to 80 % of the c
44、ontainer capacity is to use adipstick that has been pre-marked to indicate the 70 and 80 % containercapacities. The dipstick should be of such material that it shows wettingafter being immersed and withdrawn from the sample. To confirm thesample volume, insert the dipstick into the sample container
45、so that ittouches the bottom of the container at a perpendicular angle, beforeremoving the dipstick. For transparent containers, using a marked ruler orcomparing the sample container to a like container that has the 70 and80 % levels clearly marked, has been found suitable.8.3.3 Reseal the container
46、, if necessary, and return thesample container to the cooling bath or refrigerator.8.4 Air Saturation of the Sample in the Sample Container:8.4.1 Non-transparent Containers With the sample againat a temperature between 0 and 1C, take the container fromthe cooling bath or refrigerator, wipe it dry wi
47、th an absorbentmaterial, remove the cap momentarily, taking care that nowater enters, reseal, and shake it vigorously. Return it to thecooling bath or refrigerator for a minimum of 2 min.8.4.2 Transparent ContainersSince 8.3 does not requirethat the sample container be opened to verify the samplecap
48、acity, it is necessary to unseal the cap momentarily beforeresealing it so that samples in transparent containers are treatedthe same as samples in non-transparent containers. Afterperforming this task, proceed with 8.4.1.8.4.3 Repeat 8.4.1 twice more. Return the sample to the bathor refrigerator un
49、til the beginning of the procedure.8.5 Verification of Single Phase SamplesAfter drawing atest specimen and injecting it into the instrument for analysis,check the remaining sample for phase separation. If the sampleis contained in a transparent container, this observation can bemade prior to sample transfer. When the sample is contained ina non-transparent container, mix the sample thoroughly andimmediately pour a portion of the remaining sample into aclear glass container and observe for evidence of phaseseparation. A hazy appearan
