1、Designation: D2699 11Designation: 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 yea
2、r 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 This laboratory test method cov
3、ers 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 fuel is tested using astandardized single cylinder, four-stroke
4、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 that of one or more PRF blends.The O.N. of the PRF blend that ma
5、tches 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-ignition engines rate in the 88 to 101 Research O.N.range. Test
6、ing 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 parentheses are thehistorical inch-pound units. The standardiz
7、ed 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, associated with its use. It is theresponsibility of the user of thi
8、s 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 (6) and (9), A2.3.5, X3.3.7, X4.2.3.1,X4.3.4.1, X4.3.9.3, X4.3.1
9、1.4, 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 in MonocyclicAromatic Hydrocarbons by Gas ChromatographyD2700 T
10、est 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 AviationTurbine Fuels, Gasoline and Diesel FuelsD4057 Practice for M
11、anual Sampling of Petroleum andPetroleum ProductsD4175 Terminology Relating to Petroleum, PetroleumProducts, and LubricantsD4177 Practice for Automatic Sampling of Petroleum andPetroleum ProductsD4814 Specification for Automotive Spark-Ignition EngineFuelD5842 Practice for Sampling and Handling of F
12、uels 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 method is under the jurisdiction of ASTM Committee D02 onPetrole
13、um Products and Lubricants and is the direct responsibility of SubcommitteeD02.01 on Combustion Characteristics.Current edition approved May 1, 2011. Published May 2011. Originallyapproved in 1968. Last previous edition approved in 2010 as D269910. DOI:10.1520/D2699-11.2Motor O.N., determined using
14、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 Service at serviceastm.org. For Annual Book of ASTMStandards volume infor
15、mation, 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 19428-2959, United States.E456 Terminology Relating to Quality and Statis
16、ticsE542 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 LightPetroleum Distillates by Dithizone Extraction and Colo-rimetric Me
17、thod3. 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 assigned or certified value, based on experi-mental work of some nat
18、ional 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,accepted reference value is understood to apply to the Researchoctane nu
19、mber 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-ignition engine fuels of selected characteristics having anoctane num
20、ber 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 top dead center (tdc) or the top machined surface ofthe crankcase.3.1
21、.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 reading, nfor the CFR engine,anumerical indication of cylinder height
22、, indexed to a basicsetting at a prescribed compression pressure when the engine ismotored.3.1.4 detonation meter, analog, nfor knock testing, theanalog signal conditioning instrumentation that accepts theelectrical signal from the detonation pickup and provides anoutput signal for display.3.1.5 det
23、onation meter, digital, nfor knock testing, thedigital signal conditioning instrumentation that accepts theelectrical signal from the detonation pickup and provides adigital output for display.3.1.6 detonation pickup, nfor knock testing,amagnetostrictive-type transducer that threads into the enginec
24、ylinder and is exposed to combustion chamber pressure toprovide an electrical signal that is proportional to the rate-of-change of cylinder pressure.3.1.7 dynamic fuel level, nfor knock testing, test proce-dure in which the fuel-air ratio for maximum knock intensityfor sample and reference fuels is
25、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, thus permitting observation of the maxi-mum knockmeter reading.3.1
26、.8 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-librium knock intensity for each step, and selecting the leveltha
27、t produces the highest knock intensity reading.3.1.9 firing, nfor the CFR engine, operation of the CFRengine with fuel and ignition.3.1.10 fuel-air ratio for maximum knock intensity, nforknock testing, that proportion of fuel to air that produces thehighest knock intensity for each fuel in the knock
28、 testing unit,provided this occurs within specified carburetor fuel levellimits.3.1.11 guide tables, nfor knock testing, the specific rela-tionship between cylinder height (compression ratio) andoctane number at standard knock intensity for specific primaryreference fuel blends tested at standard or
29、 other specifiedbarometric pressure.3.1.12 knock, nin a spark-ignition engine, abnormal com-bustion, often producing audible sound, caused by autoignitionof the air/fuel mixture. D41753.1.13 knock intensity, nfor knock testing, a measure ofthe level of knock.3.1.14 knockmeter, analog, nfor knock tes
30、ting,the0to100 division analog indicating meter that displays the knockintensity signal from the analog detonation meter.3.1.15 knockmeter, digital, nfor knock testing,the0to999 division digital indicating meter that displays the knockintensity from the digital detonation meter.3.1.16 motoring, nfor
31、 the CFR engine, operation of theCFR engine without fuel and with the ignition shut off.3.1.17 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. D41753.1.17.
32、1 research octane number, nfor 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
33、.1.18 oxygenate, nan oxygen-containing organic com-pound, which may be used as a fuel or fuel supplement, forexample, various alcohols and ethers. D41753.1.19 primary reference fuels, nfor knock testing, isooc-tane, n-heptane, volumetrically proportioned mixtures of isooc-tane with n-heptane, or ble
34、nds of tetraethyllead in isooctanethat define the octane number scale.4Available 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 1123.1.19.1 primary reference fuel blends
35、 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.3.1.19.2 primary reference fuel blends above 100 octane,nthe millilitres per U.S. gallon of tetraethyllead in isooctaneth
36、at define octane numbers above 100 in accordance with anempirically determined relationship.3.1.20 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
37、 short intervals of time.E4563.1.20.1 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
38、in the sample fuel, testequipment, or environment.3.1.21 reproducibility conditions, nconditions where testresults are obtained with the same method on identical testitems in different laboratories with different operators usingdifferent equipment. E4563.1.22 spread, nin knock measurement, the sensi
39、tivity ofthe analog detonation meter expressed in knockmeter divisionsper octane number. (This feature is not a necessary adjustmentin the digital detonation meter.)3.1.23 standard knock intensity, analog, nfor knock test-ing, that level of knock established when a primary referencefuel blend of spe
40、cific octane number is used in the knocktesting unit at maximum knock intensity fuel-air ratio, with thecylinder height (dial indicator or digital counter reading) set tothe prescribed guide table value. The analog detonation meteris adjusted to produce an analog knockmeter reading of 50 forthese co
41、nditions.3.1.24 standard knock intensity, digital, nfor knock test-ing, that level of knock established when a primary referencefuel blend of specific octane number is used in the knocktesting unit at maximum knock intensity fuel-air ratio, with thecylinder height (dial indicator or digital counter
42、reading) set tothe prescribed guide table value. The digital detonation meterwill typically display a peak to peak voltage of approximately0.15 V for these conditions.3.1.25 toluene standardization fuels, nfor knock testing,those volumetrically proportioned blends of two or more of thefollowing: ref
43、erence 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 ratio3.2.4 IA
44、T = 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 spar
45、k-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 deto
46、nation measurementsystem. 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 obtained(1)
47、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 rate.4.2 Bra
48、cketing 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 PRFblends a
49、re 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 interpolation 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 e
