1、Designation: D2699 091Designation: 237/87Standard Test Method forResearch Octane Number of Spark-Ignition Engine Fuel1This standard is issued under the fixed designation D2699; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the ye
2、ar 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.1NOTECorrected wording in Table 4 editorial
3、ly in October 2010.1. Scope*1.1 This laboratory test method covers the quantitativedetermination of the knock rating of liquid spark-ignitionengine fuel in terms of Research O.N., except that this testmethod may not be applicable to fuel and fuel components thatare primarily oxygenates.2The sample f
4、uel is tested using astandardized single cylinder, four-stroke cycle, variable com-pression ratio, carbureted, CFR engine run in accordance witha defined set of operating conditions. The O.N. scale is definedby the volumetric composition of PRF blends. The sample fuelknock intensity is compared to t
5、hat of one or more PRF blends.The O.N. of the PRF blend that matches the K.I. of the samplefuel establishes the Research O.N.1.2 The O.N. scale covers the range from 0 to 120 octanenumber but this test method has a working range from 40 to120 Research O.N. Typical commercial fuels produced forspark-
6、ignition engines rate in the 88 to 101 Research O.N.range. Testing of gasoline blend stocks or other process streammaterials can produce ratings at various levels throughout theResearch O.N. range.1.3 The values of operating conditions are stated in SI unitsand are considered standard. The values in
7、 parentheses are thehistorical inch-pound units. The standardized CFR enginemeasurements 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, asso
8、ciated with its 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 Section 8, 13.4.1, 14.5.1, 15.6.1, Annex A1,A2.2.3.1, A2.2.3.3 (
9、6) and (9), A2.3.5, X3.3.7, X4.2.3.1,X4.3.4.1, X4.3.9.3, X4.3.11.4, and X4.5.1.8.2. Referenced Documents2.1 ASTM Standards:3D1193 Specification for Reagent WaterD2268 Test Method for Analysis of High-Purity n-Heptaneand Isooctane by Capillary Gas ChromatographyD2360 Test Method for Trace Impurities
10、in MonocyclicAromatic Hydrocarbons by Gas ChromatographyD2700 Test Method for Motor Octane Number of Spark-Ignition Engine FuelD2885 Test Method for Determination of Octane Numberof Spark-Ignition Engine Fuels by On-Line Direct Com-parison TechniqueD3703 Test Method for Hydroperoxide Number of Aviat
11、ionTurbine Fuels, Gasoline and Diesel FuelsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4814 Specification for Automotive Spark-I
12、gnition EngineFuelD5842 Practice for Sampling and Handling of Fuels forVolatility MeasurementD6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Additives by Coulo-metric Karl Fischer TitrationE344 Terminology Relating to Thermometry and Hydrom-etry1This test m
13、ethod is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.01 on Combustion Characteristics.Current edition approved Oct. 1, 2009. Published November 2009. Originallyapproved in 1968. Last previous edition approved in
14、 2008 as D269908. DOI:10.1520/D2699-09.2Motor O.N., determined using Test Method D2700, is a companion method toprovide a similar but typically lower octane rating under more severe operatingconditions.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Serv
15、ice at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to 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 1942
16、8-2959, United States.E456 Terminology Relating to Quality and StatisticsE542 Practice for Calibration of Laboratory VolumetricApparatus2.2 ANSI Standard:4C-39.1 Requirements for Electrical Analog Indicating In-struments2.3 Energy Institute Standard:5IP 224/02 Determination of Low Lead Content of Li
17、ghtPetroleum Distillates by Dithizone Extraction and Colo-rimetric Method3. Terminology3.1 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
18、 assigned or certified value, based on experi-mental work of some national or international organization, or(3) a consensus or certified value, based on collaborativeexperimental work under the auspices of a scientific orengineering group. E4563.1.1.1 DiscussionIn the context of this test method,acc
19、epted reference value is understood to apply to the Researchoctane number of specific 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-
20、ignition engine fuels of selected characteristics having anoctane number accepted reference value (O.N.ARV) determinedby round-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
21、top dead center (tdc) or the top machined surface ofthe crankcase.3.1.3.1 dial indicator reading, nfor the CFR engine,anumerical indication of cylinder height, in thousandths of aninch, indexed to a basic setting at a prescribed compressionpressure when the engine is motored.3.1.3.2 digital counter
22、reading, nfor the CFR engine,anumerical indication of cylinder height, indexed to a basicsetting at a prescribed compression pressure when the engine ismotored.3.1.4 detonation meter, nfor knock testing, the signalconditioning instrumentation that accepts the electrical signalfrom the detonation pic
23、kup 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 combustion chamber pressure toprovide an electrical signal that is proportional to the rate-of-change of cylinder pressure
24、.3.1.6 dynamic fuel level, nfor knock testing, test proce-dure in which the fuel-air ratio 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 conditi
25、on, ata constant rate, causing knock intensity to rise to a maximumand then decrease, thus permitting observation of the maxi-mum knockmeter reading.3.1.7 equilibrium fuel level, nfor knock testing, test pro-cedure in which the fuel-air ratio for maximum knock intensityfor sample and reference fuels
26、 is determined by makingincremental step changes in fuel-air ratio, observing the equi-librium knock intensity for each step, and selecting the levelthat produces the highest knock intensity reading.3.1.8 firing, nfor the CFR engine, operation of the CFRengine with fuel and ignition.3.1.9 fuel-air r
27、atio for maximum knock intensity, nforknock testing, that proportion of fuel to air that produces thehighest knock intensity for each fuel in the knock testing unit,provided this occurs within specified carburetor fuel levellimits.3.1.10 guide tables, nfor knock testing, the specific rela-tionship b
28、etween cylinder height (compression ratio) andoctane number at standard knock intensity for specific primaryreference fuel blends tested at standard or other specifiedbarometric pressure.3.1.11 knock, nin a spark-ignition engine, abnormal com-bustion, often producing audible sound, caused by autoign
29、itionof the air/fuel mixture. D41753.1.12 knock intensity, nfor knock testing, a measure ofthe level of knock.3.1.13 knockmeter, nfor knock testing,the0to100division indicating meter that displays the knock intensitysignal from the detonation meter.3.1.14 motoring, nfor the CFR engine, operation of
30、theCFR engine without fuel and with the ignition shut off.3.1.15 octane number, nfor spark-ignition engine fuel,any one of several numerical indicators of resistance to knockobtained by comparison with reference fuels in standardizedengine or vehicle tests. D41753.1.15.1 research octane number, nfor
31、 spark-ignition en-gine fuel, the numerical rating of knock resistance obtained bycomparison of its knock intensity with that of primary refer-ence fuel blends when both are tested in a standardized CFRengine operating under the conditions specified in this testmethod.3.1.16 oxygenate, nan oxygen-co
32、ntaining organic com-pound, which may be used as a fuel or fuel supplement, forexample, various alcohols and ethers. D41753.1.17 primary reference fuels, nfor knock testing, isooc-tane, n-heptane, volumetrically proportioned mixtures of isooc-tane with n-heptane, or blends of tetraethyllead in isooc
33、tanethat define the octane number scale.3.1.17.1 primary reference fuel blends below 100 octane,nthe volume % of isooctane in a blend with n-heptane thatdefines the octane number of the blend, isooctane beingassigned as 100 and n-heptane as 0 octane number.3.1.17.2 primary reference fuel blends abov
34、e 100 octane,nthe millilitres per U.S. gallon of tetraethyllead in isooctane4Available from American National Standards Institute (ANSI), 25 W. 43rd St.,4th Floor, New York, NY 10036.5Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR,U.K.D2699 0912that define octane numbers abov
35、e 100 in accordance with anempirically determined relationship.3.1.18 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.E456
36、3.1.18.1 DiscussionIn the context of this 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, testequip
37、ment, or environment.3.1.19 reproducibility conditions, nconditions where testresults are obtained with the same method on identical testitems in different laboratories with different operators usingdifferent equipment. E4563.1.20 spread, nin knock measurement, the sensitivity ofthe detonation meter
38、 expressed in knockmeter divisions peroctane number.3.1.21 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 (di
39、al indicator or digital counter reading) set to theprescribed guide table value. The detonation meter is adjustedto produce a knockmeter reading of 50 for these conditions.3.1.22 toluene standardization fuels, nfor knock testing,those volumetrically proportioned blends of two or more of thefollowing
40、: reference fuel grade toluene, n-heptane, 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 ARV = accepted reference value3.2.2 CFR = Cooperative Fuel Research3.2.3 C.R. = compression ratio3.2
41、.4 IAT = intake air temperature3.2.5 K.I. = knock intensity3.2.6 OA = Octane Analyzer3.2.7 O.N. = octane number3.2.8 PRF = primary reference fuel3.2.9 RTD = resistance thermometer device (E344) plati-num type3.2.10 TSF = toluene standardization fuel4. Summary of Test Method4.1 The Research O.N. of a
42、 spark-ignition engine fuel isdetermined 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
43、 detonation meter instrumentsystem. 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 primary reference fuel blends is adjustedto maximize K.I. for each fuel.4.1.1 The fuel-air ratio for maximum K.I. may be ob
44、tained(1) by making incremental step changes in mixture strength,observing the equilibrium K.I. value for each step, and thenselecting the condition that 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 ra
45、te.4.2 Bracketing ProceduresThe engine is calibrated 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 P
46、RFblends are selected such that, at their fuel-air ratio for maxi-mum K.I., one knocks harder (higher K.I.) and the other softer(lower K.I.) than the sample fuel. A second set of K.I.measurements for sample fuel and PRF blends is required, andthe sample fuel octane number is calculated by interpolat
47、ion inproportion to the differences in average K.I. readings. A finalcondition requires that the cylinder height used shall be withinprescribed limits around the guide table value for the calculatedO.N. Bracketing procedure ratings may be determined usingeither the equilibrium or dynamic fuel-air ra
48、tio approach.4.3 C.R. ProcedureA calibration is performed to 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 adjust
49、ed 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 condition for the ratingrequires that the sample fuel O.N. be within prescribed limitsaround that of the O.N. of the single PRF blend used tocalibrate the engine to the guide table standard K.I. condition.5. Significance and Use5.1 Research O.N.
