1、Designation: D 2700 08Designation: 236/87An American National StandardStandard Test Method forMotor Octane Number of Spark-Ignition Engine Fuel1This standard is issued under the fixed designation D 2700; the number immediately following the designation indicates the year oforiginal adoption or, in t
2、he case of revision, 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 Department of Defense.1. Scope*1.1 Thi
3、s laboratory test method covers the quantitativedetermination of the knock rating of liquid spark-ignitionengine fuel in terms of Motor octane number except that thistest method may not be applicable to fuel and fuel componentsthat are primarily oxygenates.2The sample fuel is tested in astandardized
4、 single cylinder, four-stroke cycle, variable com-pression ratio, carbureted, CFR engine run in accordance witha defined set of operating conditions. The octane number scaleis defined by the volumetric composition of primary referencefuel blends. The sample fuel knock intensity is compared tothat of
5、 one or more primary reference fuel blends. The octanenumber of the primary reference fuel blend that matches theknock intensity of the sample fuel establishes the Motor octanenumber.1.2 The octane number scale covers the range from 0 to 120octane number, but this test method has a working range fro
6、m40 to 120 octane number. Typical commercial fuels producedfor automotive spark-ignition engines rate in the 80 to 90Motor octane number range. Typical commercial fuels pro-duced for aviation spark-ignition engines rate in the 98 to 102Motor octane number range. Testing of gasoline blend stocksor ot
7、her process stream materials can produce ratings at variouslevels throughout the Motor octane number range.1.3 The values of operating conditions are stated in SI unitsand are considered standard. The values in parentheses are thehistorical inch-pounds units. The standardized CFR enginemeasurements
8、continue to be in inch-pound units only becauseof the extensive and expensive tooling that has been created forthis equipment.1.4 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 ap
9、pro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For more specifichazard statements, see Section 8, 13.4.1, 14.5.1, 15.6.1, AnnexA1, A2.2.3.1, A2.2.3.3(6) and (9), A2.3.5, X3.3.7, X4.2.3.1,X4.3.4.1, X4.3.9.3, X4.3.12.4, and X4.5.1.8.2. R
10、eferenced Documents2.1 ASTM Standards:3D 1193 Specification for Reagent WaterD 2268 Test Method for Analysis of High-Purity n-Heptaneand Isooctane by Capillary Gas ChromatographyD 2360 Test Method for Trace Impurities in MonocyclicAromatic Hydrocarbons by Gas ChromatographyD2699 Test Method for Rese
11、arch Octane Number ofSpark-Ignition Engine FuelD 2885 Test Method for Determination of Octane Numberof Spark-Ignition Engine Fuels by On-Line Direct Com-parison TechniqueD 3703 Test Method for Hydroperoxide Number of Avia-tion Turbine Fuels, Gasoline and Diesel FuelsD 4057 Practice for Manual Sampli
12、ng of Petroleum andPetroleum ProductsD 4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD 4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD 4814 Specification forAutomotive Spark-Ignition EngineFuelD 5842 Practice for Sampling and Handling of Fuels forV
13、olatility MeasurementD 6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Additives by Coulo-metric Karl Fischer TitrationE 344 Terminology Relating to Thermometry and Hydrom-etry1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Prod
14、ucts and Lubricants and is the direct responsibility of SubcommitteeD02.01 on Combustion Characteristics.Current edition approved May 1, 2008. Published June 2008. Originallyapproved in 1968. Last previous edition approved in 2007 as D 270007b.2Research octane number, determined using Test Method D
15、2699, is a compan-ion method to provide a similar but typically higher octane rating under milderoperating conditions.3For 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 t
16、o the standards Document Summary page onthe ASTM website.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.E 456 Terminology Relating to Quality and StatisticsE 542 Prac
17、tice for Calibration of Laboratory VolumetricApparatus2.2 ANSI Standard:4C-39.1 Requirements for Electrical Analog Indicating In-struments2.3 Energy Institute Standard:IP 224/02 Determination of Low Lead Content of LightPetroleum Distillates by Dithizone Extraction and Colo-rimetric Method53. Termin
18、ology3.1 Definitions:3.1.1 accepted reference value, na value that serves as anagreed-upon reference for comparison, and which is derivedas: (1) a theoretical or established value, based on scientificprinciples, (2) an assigned or certified value, based on experi-mental work of some national or inte
19、rnational organization, or(3) a consensus or certified value, based on collaborativeexperimental work under the auspices of a scientific orengineering group. E 4563.1.1.1 DiscussionIn the context of this test method,accepted reference value is understood to apply to the Motoroctane number of specifi
20、c reference materials determinedempirically under reproducibility conditions by the NationalExchange Group or another recognized exchange testing orga-nization.3.1.2 Check Fuel, nfor quality control testing, a spark-ignition engine fuel of selected characteristics having an octanenumber accepted ref
21、erence value (O.N.ARV) determined byround-robin testing under reproducibility conditions.3.1.3 cylinder height, nfor the CFR engine, the relativevertical position of the engine cylinder with respect to thepiston at top dead center (tdc) or the top machined surface ofthe crankcase.3.1.4 detonation me
22、ter, nfor knock testing, the signalconditioning instrumentation that accepts the electrical signalfrom the detonation pickup and provides an output signal fordisplay.3.1.5 detonation pickup, nfor knock testing,amagnetostrictive-type transducer that threads into the enginecylinder and is exposed to c
23、ombustion chamber pressure toprovide an electrical signal that is proportional to the rate-of-change of cylinder pressure.3.1.6 dial indicator reading, nfor the CFR engine,anumerical indication of cylinder height, in thousandths of aninch, indexed to a basic setting at a prescribed compressionpressu
24、re when the engine is motored.3.1.7 digital counter reading, nfor the CFR engine,anumerical indication of cylinder height, indexed to a basicsetting at a prescribed compression pressure when the engine ismotored.3.1.8 dynamic fuel level, nfor knock testing, test proce-dure in which the fuel-air rati
25、o for maximum knock intensityfor sample and reference fuels is determined using the fallinglevel technique that changes carburetor fuel level from a highor rich mixture condition to a low or lean mixture condition, ata constant rate, causing knock intensity to rise to a maximumand then decrease, thu
26、s permitting observation of the maxi-mum knockmeter reading.3.1.9 equilibrium fuel level, nfor knock testing, test pro-cedure in which the fuel-air ratio for maximum knock intensityfor sample and reference fuels is determined by makingincremental step changes in fuel-air ratio, observing the equi-li
27、brium knock intensity for each step, and selecting the levelwhich produces the highest knock intensity reading.3.1.10 firing, nfor the CFR engine, operation of the CFRengine with fuel and ignition.3.1.11 fuel-air ratio for maximum knock intensity, nforknock testing, that proportion of fuel to air th
28、at produces thehighest knock intensity for each fuel in the knock testing unit,provided this occurs within specified carburetor fuel levellimits.3.1.12 guide tables, nfor knock testing, the specific rela-tionship between cylinder height (compression ratio) andoctane number at standard knock intensit
29、y for specific primaryreference fuel blends tested at standard or other specifiedbarometric pressure.3.1.13 knock, nin a spark-ignition engine, abnormal com-bustion, often producing audible sound, caused by autoignitionof the air/fuel mixture. D 41753.1.14 knock intensity, nfor knock testing, a meas
30、ure ofthe level of knock.3.1.15 knockmeter, nfor knock testing,the0to100division indicating meter that displays the knock intensitysignal from the detonation meter.3.1.16 motoring, nfor the CFR engine, operation of theCFR engine without fuel and with the ignition shut off.3.1.17 motor octane number,
31、 nfor spark-ignition enginefuel, the numerical rating of knock resistance obtained bycomparison of its knock intensity with that of primary refer-ence fuels when both are tested in a standardized CFR engineoperating under the conditions specified in this test method.3.1.18 octane number, nfor spark-
32、ignition engine fuel,any one of several numerical indicators of resistance to knockobtained by comparison with reference fuels in standardizedengine or vehicle tests. D 41753.1.19 oxygenate, nan oxygen-containing organic com-pound, which may be used as a fuel or fuel supplement, forexample, various
33、alcohols and ethers. D 41753.1.20 primary reference fuel blends above 100 octane,nthe millilitres per U.S. gallon of tetraethyllead in isooctanethat define octane numbers above 100 in accordance with anempirically determined relationship.3.1.21 primary reference fuels, nfor knock testing, isooc-tane
34、, n-heptane, volumetrically proportioned mixtures of isooc-tane with n-heptane, or blends of tetraetyllead in isooctane thatdefine the octane number scale.3.1.22 primary reference fuel blends below 100 octane,nthe volume percent of isooctane in a blend with n-heptanethat defines the octane number of
35、 the blend, isooctane beingassigned as 100 and n-heptane as zero octane number.4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036, http:/www.ansi.org.5Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K., http:/www.energy
36、inst.org.uk.D27000823.1.23 repeatability conditions, nconditions where inde-pendent test results are obtained with the same method onidentical test items in the same laboratory by the same operatorusing the same equipment within short intervals of time.E 4563.1.23.1 DiscussionIn the context of this
37、test method, ashort time interval between two ratings on a sample fuel isunderstood to be not less than the time to obtain at least onerating on another sample fuel between them but not so long asto permit any significant change in the sample fuel, testequipment, or environment.3.1.24 reproducibilit
38、y conditions, nconditions where testresults are obtained with the same method on identical testitems in different laboratories with different operators usingdifferent equipment. E 4563.1.25 spread, nin knock measurement, the sensitivity ofthe detonation meter expressed in knockmeter divisions peroct
39、ane number.3.1.26 standard knock intensity, nfor knock testing, thatlevel of knock established when a primary reference fuel blendof specific octane number is used in the knock testing unit atmaximum knock intensity fuel-air ratio, with the cylinderheight (dial indicator or digital counter reading)
40、set to theprescribed guide table value. The detonation meter is adjustedto produce a knockmeter reading of 50 for these conditions.3.1.27 toluene standardization fuels, nfor knock testing,those volumetrically proportioned blends of two or more of thefollowing: reference fuel grade toluene, n-heptane
41、, and isooc-tane that have prescribed rating tolerances for O.N.ARVdeter-mined by round-robin testing under reproducibility conditions.3.2 Abbreviations:3.2.1 ARVaccepted reference value3.2.2 CFRCooperative Fuel Research3.2.3 C.R.compression ratio3.2.4 IATintake air temperature3.2.5 K.I.knock intens
42、ity3.2.6 MIXTmixture temperature3.2.7 OAoctane analyzer3.2.8 O.N.octane number3.2.9 PRFprimary reference fuel3.2.10 RTDresistance thermometer device (TerminologyE 344), platinum type3.2.11 TSFtoluene standardization fuel4. Summary of Test Method4.1 The Motor O.N. of a spark-ignition engine fuel isde
43、termined using a standard test engine and operating condi-tions to compare its knock characteristic with those of PRFblends of known O.N. Compression ratio and fuel-air ratio areadjusted to produce standard K.I. for the sample fuel, asmeasured by a specific electronic detonation meter instrumentsyst
44、em. A standard K.I. guide table relates engine C.R. to O.N.level for this specific method. The fuel-air ratio for the samplefuel and each of the PRF blends is adjusted to maximize K.I.for each fuel.4.1.1 The fuel-air ratio for maximum K.I. may be obtained(1) by making incremental step changes in mix
45、ture strength,observing the equilibrium K.I. value for each step, and thenselecting the condition which maximizes the reading or (2)bypicking the maximum K.I. as the mixture strength is changedfrom either rich-to-lean or lean-to-rich at a constant rate.4.2 Bracketing ProceduresThe engine is calibrat
46、ed tooperate at standard K.I. in accordance with the guide table. Thefuel-air ratio of the sample fuel is adjusted to maximize theK.I., and then the cylinder height is adjusted so that standardK.I. is achieved. Without changing cylinder height, two PRFsare selected such that, at their fuel-air ratio
47、 for maximum K.I.,one knocks harder (higher K.I.) and the other softer (lowerK.I.) than the sample fuel. A second set of K.I. measurementsfor sample fuel and reference fuels is required, and the samplefuel O.N. is calculated by interpolation in proportion to thedifferences in average K.I. readings.
48、A final condition requiresthat the cylinder height used shall be within prescribed limitsaround the guide table value for the calculated O.N. Bracketingprocedure ratings may be determined using either the equilib-rium or dynamic fuel-air ratio approach.4.3 C.R. ProcedureA calibration is performed to
49、 establishstandard K.I. using the cylinder height specified by the guidetable for the O.N. of the selected PRF. The fuel-air ratio of thesample fuel is adjusted to maximize the K.I. under equilibriumconditions; the cylinder height is adjusted so that standard K.I.is achieved. The calibration is reconfirmed and the sample fuelrating is repeated to establish the proper conditions a secondtime. The average cylinder height reading for the sample fuel,compensated for barometric pressure, is converted directly toO.N. using the guide table. A final
