1、Designation: D 5482 01An American National StandardStandard Test Method forVapor Pressure of Petroleum Products (Mini MethodAtmospheric)1This standard is issued under the fixed designation D 5482; the number immediately following the designation indicates the year oforiginal adoption or, in the case
2、 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 a procedure for the determina-tion of total vapor pressure of pet
3、roleum products 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 c
4、ontaining oxygen-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
5、of the sample due to some small vaporization of the sampleand dissolved air into the air of the confined space.1.1.1 Some gasoline-oxygenate blends my show a hazewhen cooled to 0 to 1 C. If a haze is observed in 8.5, it shallbe indicated in the reporting of results. The precision and biasstatements
6、for hazy samples have not been determined (seeNote 6).1.2 This test method is a modification of Test MethodD 5191 (Mini Method) in which the test chamber is atatmospheric pressure prior to sample injection.1.3 This test method covers the use of automated vaporpressure instruments that perform measur
7、ements on liquidsample 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
8、 obtained on the same material when tested by TestMethod D 4953.1.5 The values stated in acceptable SI units are regarded asstandard. The values given in parentheses are provided forinformation only.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its
9、use. It is theresponsibility 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 specific hazardstatements, see 7.2 through 7.7.)2. Referenced Documents2.1 ASTM Standards:D 4057 Practice for
10、Manual Sampling of Petroleum andPetroleum Products2D 4953 Test Method for Vapor Pressure of Gasoline andGasoline-Oxygenate Blends (Dry Method)2D 5190 Test Method for Vapor Pressure of Petroleum Prod-ucts (Automatic Method)2D 5191 Test Method for Vapor Pressure of Petroleum Prod-ucts (Mini Method)23.
11、 Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 dry vapor pressure equivalent (DVPE)a value cal-culated by a correlation equation (see 13.2) from the totalpressure.3.1.1.1 DiscussionThe DVPE is expected to be equivalentto the value obtained on the sample by Test Method D 4953.3.
12、1.2 total pressurethe observed pressure measured in theexperiment that is the resultant pressure increase from theinitial ambient atmospheric pressure.4. Summary of Test Method4.1 A known volume of chilled, air-saturated sample isintroduced into a thermostatically controlled test chamber, theinterna
13、l volume of which is five times that of the total testspecimen introduced into the chamber. The test 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 testtempe
14、rature, 37.8C (100F). The resulting rise in pressure inthe chamber is measured using a pressure transducer sensorand indicator.4.2 The measured total vapor pressure is converted to aDVPE by use of a correlation equation (see 13.2).1This test method is under the jurisdiction of ASTM Committee D02 onP
15、etroleum products and Lubricants and is the direct responsibility of SubcommitteeD02.08.ODon RVP and V/L Ratio.Current edition approved May 10, 2001. Published July 2001. Originallypublished as D 5482 93. Last previous edition D 5482 99.2Annual Book of ASTM Standards, Vol 05.02.1*A Summary of Change
16、s 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.5. Significance and Use5.1 Vapor pressure is an important physical property ofvolatile liquids.5.2 Vapor pressure is critically important fo
17、r both automo-tive and aviation 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 Appara
18、tusThe type of apparatus3suitable 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
19、 of liquid and vapor and be 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.
20、05 psi). The pressure measurement 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 resi
21、stance thermometer shall be 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 forintroduct
22、ion of the test specimen into 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 o
23、f the test specimen being dispensed, 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
24、 am-bient and above ambient 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 sh
25、all be periodically checked(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 transduc
26、er and cleaning of the cell.NOTE 2A vacuum source is an alternate means for cleaning of thecell.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 s
27、pecifications of the Committee on Analytical Reagents ofthe American Chemical Society where such specifications areavailable.4Lower 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
28、Cyclohexane,(WarningCyclohexane 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).7.5 2,3-Dimethylbutane,(Warning2,3-dimethylbutane isflammable and a health hazard
29、).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 evaporation and the resulting changesin co
30、mposition 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 D 4057, except do not use 10.3.1.8 of PracticeD 4057, Sampling by Water Displacement, for fuels containingoxygenates
31、. 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. If a second determination is n
32、ecessary,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 are detected.3The following inst
33、ruments have been found satisfactory for use in this testprocedure as determined by interlaboratory testing: Herzog Mini Reid VaporPressure Model MP970available from Varlen Instruments, Inc., 2777 WashingtonBlvd., Bellwood, IL 60104 and ABB Model 4100available from ABB ProcessAnalytics, Lewisburg, W
34、V.4Reagent Chemicals, American Chemical Society Specifications, AmericanChemical Society, Washington, DC. For suggestions on the testing of reagents notlisted by the American Chemical Society, see Analar Standards for LaboratoryChemicals, BDH Ltd., Poole, Dorset, U.K., and the United States Pharmaco
35、peiaand National Formulary, U.S. Pharmacopeial Convention, Inc. (USPC), Rockville,MD.D 548228.1.6 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 conta
36、iner andcontents in an ice bath or refrigerator to the 0 to 1C (32 to34F) range prior 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
37、 bathor refrigerator at the same time as the sample.8.3 Verification of Sample Container 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 suitab
38、le gage, confirm that the sample volume equals 70 to80 % of the container capacity (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 conta
39、iner is filled to less than 70 volume % of the containercapacity.8.3.2 If the container 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-transparen
40、t containers, one way to confirm that thesample volume equals 70 to 80 % of the container 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 sa
41、mple. To confirm thesample volume, insert the dipstick into the sample container 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
42、and80 % levels clearly marked, has been found suitable.8.3.3 Reseal the container, 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 ContainersWith the sample againat a temperature between 0
43、 and 1C, take the container fromthe cooling bath or refrigerator, wipe it dry with 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
44、 8.3 does not requirethat the sample container be opened to verify the samplecapacity, 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.
45、1.8.4.3 Repeat 8.4.1 twice more. Return the sample to the bathor refrigerator until 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 c
46、ontained 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 phaseseparati
47、on. A hazy appearance is to be carefully distinguishedfrom separation into two distinct phases. The hazy appearanceshall not be considered grounds for rejection of the fuel. If asecond phase is observed, discard the test and the sample. Hazysamples may be analyzed (see Report section).9. Preparation
48、 of Apparatus9.1 Prepare the instrument for operation in accordance withthe manufacturers instructions.9.2 Prepare the sample introduction accessories, if required,in accordance with the manufacturers instructions.9.3 Chill the sample syringe to between 0 and 4.5C (32 and40F) in a refrigerator or ic
49、e bath. Avoid water contaminationof the syringe reservoir by suitably sealing the outlet of thesyringe during the cooling process.9.4 Clean and dry the test chamber in accordance with themanufacturers instructions. With the test chamber sealed,observe that the instrument display is stable and does notexceed 0.00 6 0.20 kPa (0.00 6 0.03 psi).9.5 If in doubt of the cleanliness of the cell, refer to thecleaning procedure in the manufacturers instructions, or if thedisplay does not return to zero, refer to the calibrationprocedure in the m
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