1、Designation: D2700 13aDesignation: 236/87Standard Test Method forMotor Octane Number of Spark-Ignition Engine Fuel1This standard is issued under the fixed designation D2700; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year
2、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 cover
3、s the quantitativedetermination of the knock rating of liquid spark-ignitionengine fuel in terms of Motor octane number, including fuelsthat contain up to 25 % v/v of ethanol. However, this testmethod may not be applicable to fuel and fuel components thatare primarily oxygenates.2The sample fuel is
4、tested in astandardized 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 intensit
5、y is compared tothat of 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
6、has a working range from40 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 gas
7、oline blend stocksor other 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
8、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 this s
9、tandard to establish appro-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.
10、12.4, 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 ChromatographyD2699
11、Test Method for Research 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 Fuels, Gasoline and Diesel FuelsD4057 Practice f
12、or 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 EngineFuelD5842 Practice for Sampling and Handling
13、of Fuels forVolatility MeasurementD6304 Test Method for Determination of Water in Petro-leum Products, Lubricating Oils, and Additives by Cou-lometric Karl Fischer Titration1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the
14、 direct responsibility ofSubcommittee D02.01 on Combustion Characteristics.Current edition approved July 15, 2013. Published September 2013. Originallyapproved in 1968. Last previous edition approved in 2013 as D2700 13. DOI:10.1520/D2700-13A.2Research octane number, determined using Test Method D26
15、99, is a companionmethod 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 to th
16、e standards Document Summary page onthe ASTM website.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1E344 Terminology Relating to Thermometry and Hydrom-etryE456 Termino
17、logy Relating to Quality and StatisticsE542 Practice for Calibration of Laboratory VolumetricApparatusE1064 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-struments2.3 Energy Institute Standard
18、:IP 224/02 Determination of Low Lead Content of LightPetroleum Distillates by Dithizone Extraction and Colo-rimetric Method53. 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 estab
19、lished 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 scientific orengineering group. E4563.1.1
20、.1 DiscussionIn the context of this test method,accepted reference value is understood to apply to the Motoroctane number of specific reference materials determinedempirically under reproducibility conditions by the NationalExchange Group or another recognized exchange testing orga-nization.3.1.2 Ch
21、eck Fuel, nfor quality control testing, a spark-ignition engine fuel of selected characteristics having an octanenumber accepted reference value (O.N.ARV) determined byround-robin testing under reproducibility conditions.3.1.3 cylinder height, nfor the CFR engine, the relativevertical position of th
22、e engine cylinder with respect to thepiston at top dead center (tdc) or the top machined surface ofthe crankcase.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
23、 for display.3.1.5 detonation meter, digital, nfor knock testing, thedigital signal conditioning instrumentation that accepts theelectrical signal from the detonation pickup and provides adigital output signal for display.3.1.6 detonation pickup, nfor knock testing,amagnetostrictive-type transducer
24、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.3.1.7 dial indicator reading, nfor the CFR engine,anumerical indication of cylinder height, in thousandths of aninch, inde
25、xed to a basic setting at a prescribed compressionpressure when the engine is motored.3.1.8 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.3.1.9 dynamic fuel level, nfor k
26、nock 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 condition, ata constant rate, causing kn
27、ock intensity to rise to a maximumand then decrease, thus permitting observation of the maxi-mum knockmeter reading.3.1.10 equilibrium fuel level, nfor knock testing, testprocedure in which the fuel-air ratio for maximum knockintensity for sample and reference fuels is determined bymaking incrementa
28、l step changes in fuel-air ratio, observingthe equilibrium knock intensity for each step, and selecting thelevel which produces the highest knock intensity reading.3.1.11 firing, nfor the CFR engine, operation of the CFRengine with fuel and ignition.3.1.12 fuel-air ratio for maximum knock intensity,
29、 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.3.1.13 guide tables, n for knock testing, the specificrelationship between cylinder height (compressio
30、n ratio) andoctane number at standard knock intensity for specific primaryreference fuel blends tested at standard or other specifiedbarometric pressure.3.1.14 knock, nin a spark-ignition engine, abnormalcombustion, often producing audible sound, caused by autoi-gnition of the air/fuel mixture. D417
31、53.1.15 knock intensity, nfor knock testing, a measure ofthe level of knock.3.1.16 knockmeter, analog, nfor knock testing,the0to100 division analog indicating meter that displays the knockintensity signal from the analog detonation meter.3.1.17 knockmeter, digital, nfor knock testing,the0to999divisi
32、on digital indicating software meter that displays theknock intensity from the digital detonation meter.3.1.18 motoring, nfor the CFR engine, operation of theCFR engine without fuel and with the ignition shut off.3.1.19 motor octane number, nfor spark-ignition enginefuel, the numerical rating of kno
33、ck 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.3.1.20 octane number, nfor spark-ignition engine fuel,any one of several numerical indicators
34、 of resistance to knock4Available 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.energyinst.org.uk.D2700 13a2obtained by comparison with refere
35、nce fuels in standardizedengine or vehicle tests. D41753.1.21 oxygenate, nan oxygen-containing organiccompound, which may be used as a fuel or fuel supplement, forexample, various alcohols and ethers. D41753.1.22 primary reference fuel blends above 100 octane,nthe millilitres per U.S. gallon of tetr
36、aethyllead in isooctanethat define octane numbers above 100 in accordance with anempirically determined relationship.3.1.23 primary reference fuels, nfor knock testing,isooctane, n-heptane, volumetrically proportioned mixtures ofisooctane with n-heptane, or blends of tetraetyllead in isooc-tane that
37、 define the octane number scale.3.1.24 primary reference fuel blends below 100 octane,nthe volume percent of isooctane in a blend with n-heptanethat defines the octane number of the blend, isooctane beingassigned as 100 and n-heptane as zero octane number.3.1.25 repeatability conditions, nconditions
38、 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. E4563.1.25.1 DiscussionIn the context of this test method, ashort time interval between two ratings on a sampl
39、e 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.3.1.26 reproducibility conditions, nconditions where testresults are obtained with th
40、e same method on identical testitems in different laboratories with different operators usingdifferent equipment. E4563.1.27 spread, nin knock measurement, the sensitivity ofthe analog detonation meter expressed in knockmeter divisionsper octane number. (This feature is not a necessary adjustmentin
41、the digital detonation meter.)3.1.28 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
42、 or digital counter reading) set tothe prescribed guide table value. The analog detonation meteris adjusted to produce an analog knockmeter reading of 50 forthese conditions.3.1.29 standard knock intensity, digital, nfor knocktesting, that level of knock established when a primary refer-ence fuel bl
43、end 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 reading) set tothe prescribed guide table value. The digital detonation meterwill display a peak to peak voltage of approximately 0.25
44、V forthese conditions.3.1.30 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 r
45、eproducibility 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 intensity3.2.6 MIXTmixture temperature3.2.7 OAoctane analyzer3.2.8 O.N.octane number3.2.9 PRFprimary reference fuel
46、3.2.10 RTDresistance thermometer device (TerminologyE344), platinum type3.2.11 TSFtoluene standardization fuel4. Summary of Test Method4.1 The Motor 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
47、 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 measurementsystem. A standard K.I. guide table relates engine C.R. to O.N.level for this specific method. The fuel-air ratio for t
48、he 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 mixture strength,observing the equilibrium K.I. value for each step, and thenselecting the condition which maximizes t
49、he 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 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 for maximum K.I.,one knocks harder (higher K.I.) and the
