1、Designation: D2699 13Designation: 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., including fuels thatcontain up to 25 % v/v of ethanol. However, this test methodmay not be applicable to fuel and fuel components that areprimarily oxygenates.2The sample fuel is test
4、ed 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 that of one
5、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-ignition en
6、gines 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 parenthese
7、s 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, associated with
8、 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 specificwarning statements, 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)
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 in Monocyc
10、licAromatic Hydrocarbons by Gas ChromatographyD2700 Test Method for Motor Octane Number of Spark-Ignition Engine FuelD2885 Test Method for Determination of Octane Number ofSpark-Ignition Engine Fuels by On-Line Direct Compari-son TechniqueD3703 Test Method for Hydroperoxide Number of AviationTurbine
11、 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-Ignition En
12、gineFuelD5842 Practice for Sampling and Handling of Fuels forVolatility MeasurementD6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Additives by Cou-lometric Karl Fischer TitrationE344 Terminology Relating to Thermometry and Hydrom-etryE456 Terminology Relat
13、ing to Quality and StatisticsE542 Practice for Calibration of Laboratory VolumetricApparatus1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.01 on Combustion Characteristics.Curren
14、t edition approved May 1, 2013. Published September 2013. Originallyapproved in 1968. Last previous edition approved in 2012 as D2699 12a. DOI:10.1520/D2699-13.2Motor O.N., determined using Test Method D2700, is a companion method toprovide a similar but typically lower octane rating under more seve
15、re 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 information, refer to the standards Document Summary page onthe ASTM website.*A Summary of Changes section appears
16、at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E1064 Test Method for Water in Organic Liquids by Coulo-metric Karl Fischer Titration2.2 ANSI Standard:4C-39.1 Requirements for Electrical Analog Indicating In
17、-struments2.3 Energy Institute Standard:5IP 224/02 Determination of Low Lead Content of LightPetroleum 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 i
18、s 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 international organization, or(3) a consensus or certified value, based on collaborativeexperimental work under the auspices of a sc
19、ientific orengineering group. E4563.1.1.1 DiscussionIn the context of this test method,accepted reference value is understood to apply to the Researchoctane number of specific reference materials determinedempirically under reproducibility conditions by the NationalExchange Group or another recogniz
20、ed exchange testing orga-nization.3.1.2 Check Fuel, nfor quality control testing, a spark-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
21、engine, the relativevertical position of the engine cylinder with respect to thepiston at top dead center (tdc) or the top machined surface ofthe crankcase.3.1.3.1 dial indicator reading, nfor the CFR engine,anumerical indication of cylinder height, in thousandths of aninch, indexed to a basic setti
22、ng 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, indexed to a basicsetting at a prescribed compression pressure when the engine ismotored.3.1.4 detonation meter, analog, nfor knock testing
23、, theanalog signal conditioning instrumentation that accepts theelectrical signal from the detonation pickup and provides anoutput signal for display.3.1.5 detonation meter, digital, nfor knock testing, thedigital signal conditioning instrumentation that accepts theelectrical signal from the detonat
24、ion pickup and provides adigital output for display.3.1.6 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 p
25、ressure.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 determined using the fallinglevel technique that changes carburetor fuel level from a highor rich mixture condition to a low or lean mixture
26、condition, ata constant rate, causing knock intensity to rise to a maximumand then decrease, thus permitting observation of the maxi-mum knockmeter reading.3.1.8 equilibrium fuel level, nfor knock testing, test pro-cedure in which the fuel-air ratio for maximum knock intensityfor sample and referenc
27、e fuels 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.3.1.9 firing, nfor the CFR engine, operation of the CFRengine with fuel and ignition.3.1.10 fu
28、el-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 testing unit,provided this occurs within specified carburetor fuel levellimits.3.1.11 guide tables, n for knock testing, the specificrelatio
29、nship between cylinder height (compression ratio) andoctane number at standard knock intensity for specific primaryreference fuel blends tested at standard or other specifiedbarometric pressure.3.1.12 knock, nin a spark-ignition engine, abnormalcombustion, often producing audible sound, caused by au
30、toi-gnition of 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 testing,the0to100 division analog indicating meter that displays the knockintensity signal from the analog detonation meter.3.1.15 knockmeter, di
31、gital, nfor knock testing,the0to999division digital indicating meter that displays the knock inten-sity from the digital 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 octane number, nfor spark-ignition engine fuel
32、,any one of several numerical indicators of resistance to knockobtained by comparison with reference fuels in standardizedengine or vehicle tests. D41753.1.17.1 research octane number, nfor spark-ignition en-gine fuel, the numerical rating of knock resistance obtained bycomparison of its knock inten
33、sity with that of primary refer-ence fuel blends when both are tested in a standardized CFRengine operating under the conditions specified in this testmethod.3.1.18 oxygenate, nan oxygen-containing organiccompound, which may be used as a fuel or fuel supplement, forexample, various alcohols and ethe
34、rs. D41754Available 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 1323.1.19 primary reference fuels, nfor knock testing,isooctane, n-heptane, volumetrically proportione
35、d mixtures ofisooctane with n-heptane, or blends of tetraethyllead in isooc-tane that define the octane number scale.3.1.19.1 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
36、 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 isooctanethat define octane numbers above 100 in accordance with anempirically determined relationship.3.1.20 repeatability conditions, nconditions where in
37、de-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. E4563.1.20.1 DiscussionIn the context of this test method, ashort time interval between two ratings on a sample fuel is
38、understood 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.3.1.21 reproducibility conditions, nconditions where testresults are obtained with the same me
39、thod on identical testitems in different laboratories with different operators usingdifferent equipment. E4563.1.22 spread, nin knock measurement, the sensitivity ofthe analog detonation meter expressed in knockmeter divisionsper octane number. (This feature is not a necessary adjustmentin the digit
40、al detonation meter.)3.1.23 standard knock intensity, analog, nfor knocktesting, that level of knock established when a primary refer-ence fuel blend of specific octane number is used in the knocktesting unit at maximum knock intensity fuel-air ratio, with thecylinder height (dial indicator or digit
41、al counter reading) set tothe prescribed guide table value. The analog detonation meteris adjusted to produce an analog knockmeter reading of 50 forthese conditions.3.1.24 standard knock intensity, digital, nfor knocktesting, that level of knock established when a primary refer-ence fuel blend of sp
42、ecific 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 digital detonation meterwill typically display a peak to peak voltage of approximately0.15
43、V for these conditions.3.1.25 toluene standardization fuels, nfor knock testing,those volumetrically proportioned blends of two or more of thefollowing: reference fuel grade toluene, n-heptane, and isooc-tane that have prescribed rating tolerances for O.N.ARVdeter-mined by round-robin testing under
44、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 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.
45、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 spark-ignition engine fuel isdetermined using a standard test engine and operating condi-tions to compare its knock characteristic with those of PRF
46、blends 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 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 samp
47、lefuel 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) by making incremental step changes in mixture strength,observing the equilibrium K.I. value for each step, and thenselecting the condition that
48、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 calibrated tooperate at standard K.I. in accordance with the guide table. Thefuel-air ratio of the sample fuel i
49、s adjusted to maximize theK.I., and then the cylinder height is adjusted so that standardK.I. is achieved. Without changing cylinder height, two PRFblends 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 interpolation inproportion to the differences in average K.I. readings. A finalcondition requires that the cylinder heig
