1、Designation: D7153 151IP 52915Standard Test Method forFreezing Point of Aviation Fuels (Automatic Laser Method)1This standard is issued under the fixed designation D7153; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of
2、last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1NOTEFigures 3, A1.3, and A1.5 were corrected editorially in March 2016.1. Scope*1.1 This test method covers the determination of
3、the tem-perature below which solid hydrocarbon crystals may form inaviation turbine fuels.1.2 This test method is designed to cover the temperaturerange of 80 C to 20 C; however, the interlaboratory studymentioned in 12.4 has only demonstrated the test method withfuels having freezing points in the
4、range of 60 C to 42 C.1.3 The values stated in SI units are to be regarded asstandard. No other units of measurement are included in thisstandard.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 stan
5、dard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D2386 Test Method for Freezing Point of Aviation FuelsD4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD4
6、177 Practice for Automatic Sampling of Petroleum andPetroleum Products2.2 Energy Institute Standard:IP 16 Determination Freezing Point of Aviation Fuels33. Terminology3.1 Definitions:3.1.1 freezing point, nin aviation fuels, the fuel tempera-ture at which solid hydrocarbon crystals, formed on coolin
7、g,disappear when the temperature of the fuel is allowed to riseunder specified conditions of test.3.2 Definitions of Terms Specific to This Standard:3.2.1 automatic laser method, nthe procedures of auto-matically cooling a liquid aviation fuel specimen until solidhydrocarbon crystals appear, followe
8、d by controlled warmingand recording of temperature at which hydrocarbon crystalscompletely redissolve into the liquid phase.3.3 Symbols:Cd = the specimen temperature at which the appearance ofthe first crystals are detected in the specimen by anoptical crystal detector under specified conditions of
9、test.Co = the specimen temperature at which the appearance ofopacity in the specimen is detected by an opticalopacity detector under specified conditions of test.Do = the specimen temperature at which the disappearanceof opacity in the specimen is detected by an opticalopacity detector under specifi
10、ed conditions of test.4. Summary of Test Method4.1 Aspecimen is cooled at a rate of 10 C min 6 5 C minwhile continuously being illuminated by a laser light source.The specimen is continuously monitored by optical crystal andopacity detectors for the first formation of solid hydrocarboncrystals. Once
11、 the hydrocarbon crystals are detected by bothsets of optical detectors, the specimen is then warmed at a rateof 3 C min 6 0.5 C min. When initial opacity in thespecimen disappears, the specimen is then warmed at a rate of12 C min 6 l C min. The specimen temperature at whichthe last hydrocarbon crys
12、tals return to the liquid phase, asdetected by the crystal detector, is recorded as the freezingpoint.4.2 In certain circumstances, as measured by the apparatus,the specimen is reheated to approximately 10 C, then cooledat the rate in 4.1 until hydrocarbon crystals are detected by thecrystal detecto
13、r. The specimen is then warmed at a rate of1This test method is under the jurisdiction of ASTM Committee D02 onPetroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility ofSubcommittee D02.07 on Flow Properties.Current edition approved April 1, 2015. Published April 2015. Orig
14、inallyapproved in 2005. Last previous edition approved in 2010 as D7153 05 (2010).DOI: 10.1520/D7153-15E01.2For 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 stand
15、ards Document Summary page onthe ASTM website.3Annual Book of IP Standards Methods, Vol 1. Available from Energy Institute,61 New Cavendish St., London, WIG 7AR, U.K.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, PO Box C700, Wes
16、t Conshohocken, PA 19428-2959. United States112 C min 6 l C min, until the last hydrocarbon crystalsreturn to the liquid phase. The specimen temperature at whichthe last hydrocarbon crystals return to the liquid phase, asdetected by the crystal detector, is recorded as the freezingpoint.5. Significa
17、nce and Use5.1 The freezing point of an aviation fuel is the lowesttemperature at which the fuel remains free of solid hydrocar-bon crystals which, if present in the fuel system of the aircraft,can restrict the flow of fuel through filters. The temperature ofthe fuel in the aircraft tank normally de
18、creases during flightdepending on aircraft speed, altitude, and flight duration. Thefreezing point of the fuel shall always be lower than theminimum operational fuel temperature.5.2 Petroleum blending operations require precise measure-ment of the freezing point.5.3 This test method expresses result
19、s to the nearest 0.1 C,and it eliminates most of the operator time and judgmentrequired by Test Method D2386.5.4 When a specification requires Test Method D2386,donot substitute this test method or any other test method.6. Apparatus6.1 Automatic Apparatus4This apparatus consists of amicroprocessor-c
20、ontrolled test cell that is capable of coolingand heating the specimen, dual optical detectors to monitor theappearance and disappearance of crystals and opacity, andrecording the temperature of the specimen. A detailed descrip-tion of the apparatus is provided in Annex A1.6.2 The apparatus shall be
21、 equipped with a specimenchamber, optical detectors, laser light source, digital display,cooling and heating systems, and a specimen temperaturemeasuring device.6.3 The temperature measuring device in the specimenchamber shall be capable of measuring the temperature of thespecimen from 80 C to +20 C
22、 at a resolution of 0.1 C andaccuracy of 0.1 C.6.4 The apparatus shall be capable of cooling the specimenat a rate of 10 C min 6 5 C min, heating the specimen atrates of 3 C min 6 0.5 C min and 12 C min 6 1 C minover the temperature range of 80 C to +20 C.NOTE 1The apparatus described is covered by
23、a patent. If you areaware of an alternative(s) to the patented item, please attach to your ballotreturn a description of the alternatives. All suggestions will be consideredby the committee.NOTE 2The software version used in this apparatus is version V 5.3.6.5 Standard Syringe, capable of injecting
24、approximately10 mL 6 2 mL of the specimen, with a tip or an adapter tip thatwill fit the inlet of the test cell. A disposable 10 mL syringewith a Luer type cone connection has been found suitable.6.6 Waste Receiving Container, capable of collecting theoverflow when the specimen is injected into the
25、test cell. A400 mL standard glass beaker has been found suitable.7. Sampling7.1 Obtain a sample in accordance with Practice D4057 orD4177.7.2 At least 30 mL of sample is required for each test.8. Preparation of Apparatus8.1 Install the apparatus for operation in accordance withthe manufacturers inst
26、ructions.8.2 Turn on the main power switch of the analyzer.9. Calibration and Standardization9.1 Ensure that all of the manufacturers instructions forcalibration of the mechanical and electronic systems andoperation of the apparatus are followed.9.2 To verify the performance of the apparatus, an avi
27、ationturbine fuel sample for which extensive data has been obtainedby Test Method D2386 may be used. Samples such as thoseused in the ASTM interlaboratory crosscheck program wouldmeet this criterion. Such verification materials can also beprepared from intra-company crosschecks.9.3 At intervals of n
28、ot more than 12 months, check thetemperature measuring system against a temperature measur-ing device that has a current calibration certificate.9.4 Verify the correct functioning of the apparatus in accor-dance with the manufacturers instructions using a verificationliquid (9.2) when first installe
29、d and thereafter at intervals notexceeding one month.10. Procedure10.1 Draw 10 mL 6 2 mL bubble-free portion of sampleinto a syringe. Connect the syringe to the inlet port (Fig. 1).Rinse the test cell by injecting 10 mL 6 2 mL of specimen intothe test cell; the specimen excess will flow into the was
30、tereceiving container (Fig. 2)10.2 Rinse the test cell a second time by repeating 10.1.10.3 Draw a 10 mL 6 2 mL bubble-free portion of sampleinto a syringe.10.4 Connect the syringe to the inlet port (Fig. 1). Dispensethe specimen into the test cell; the specimen excess will flowinto the waste receiv
31、ing container (Fig. 2). Leave the syringeconnected to the sample inlet for the entire duration of the test.10.5 Start the operation of the apparatus according themanufacturers instructions. From this point through Section11, the apparatus automatically controls the procedure.10.5.1 Cool the specimen
32、 at a rate of 10 C min 65 C min while continuously illuminating with a polarizedlaser light source. Monitor the specimen continuously with twooptical detectors, an opacity detector and a crystal detector(Fig. 3), for the first formation of solid hydrocarbon crystals.4The sole source of supply of the
33、 apparatus known to the committee at this timeis ISL model FZP 5G2s series Freezing Point Analyzer, available from PAC - ISL,BP 70285 - VERSON, 14653 CARPIQUET Cedex, France. If you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments wi
34、ll receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.D7153 151210.5.2 Once the appearance of the first crystals (Cd)isdetected on the crystal detector and opacity (Co) is detected onthe opacity detector, warm the specimen at a rate of 3 C min6 0.5
35、 C min until the disappearance of the opacity (Do)isdetected on the opacity detector. At that point, warm thespecimen at a rate of 12 C min 6 l C min while it is stillmonitored by the crystal detector. When the disappearance ofthe last crystals is detected on the crystal detector, record thespecimen
36、 temperature at which the last hydrocarbon crystalsreturn to the liquid phase. Refer to A1.2.12 and Fig. A1.5 fordetection curve examples.10.5.3 Compare this recorded temperature with the tem-perature at which the first crystals were detected (Cd). Whenthe recorded temperature is warmer than the (Cd
37、) temperature,it is recorded as the freezing point.NOTE 3In most cases, 10.5.3 is considered the termination of the test.(See 10.5.4.)10.5.4 In certain circumstances, as measured by theapparatus, perform a second test cycle as follows in 10.6.NOTE 4This circumstance may indicate the presence of cont
38、aminationof the specimen with material other than aviation fuel and the statedprecisions may not apply.10.6 Second Test Cycle:10.6.1 The original specimen is warmed up to approxi-mately 10 C and then cooled at a rate of 10 C min 65 C min while continuously being illuminated by a polarizedlaser light
39、 source. Monitor the specimen continuously with theoptical crystal detector (Fig. 3) for the first formation of solidhydrocarbon crystals.10.6.2 Once the appearance of the first crystals (Cd) aredetected on the crystal detector, continue to cool the specimenan additional 5 C and then discontinue the
40、 cooling.10.6.3 Warm the specimen a rate of 12 C min 6 l C minwhile it is still monitored by the crystal detector. When thedisappearance of the last crystals is detected on the crystaldetector, record the specimen temperature at which the lasthydrocarbon crystals return to the liquid phase as the fr
41、eezingpoint.NOTE 5When condition described in 10.5.4 is encountered, thisindicates that the sample may be contaminated. In that case, in order tominimize the test duration, only the 12 C 6 1 C warming rate is used.10.7 Once the freezing point is recorded, the test cell iswarmed up to ambient tempera
42、ture. Fig. A1.5 gives twoexamples of the testing process: one with a neat jet fuel, andone with a contaminated jet fuel.10.8 The freezing point value will be automatically roundedto the nearest 0.1 C and displayed by the apparatus.10.9 Disconnect the injection syringe from the sample inlet.The clean
43、ing of the test cell will be carried out during theperformance of the next test.11. Report11.1 Report the temperature recorded in 10.8 as the freezingpoint, determined by Test Method D7153.12. Precision and Bias12.1 PrecisionThe precision of this test method as deter-mined by the statistical examina
44、tion of the interlaboratory5testresults is as follows:12.1.1 RepeatabilityThe difference between two test re-sults obtained by the same operator with the same apparatusunder constant operating conditions on identical test materialwould, in the long run, in the normal and correct operation ofthis tes
45、t method, exceed 0.6 C only in one case in twenty.5Supporting data (the results of the 2003 Interlaboratory Cooperative TestProgram ) have been filed atASTM International Headquarters and may be obtainedby requesting Research Report RR:D02-1572.FIG. 1 Syringe Inserted in Inlet PortFIG. 2 Waste Conta
46、inerD7153 151312.1.2 ReproducibilityThe difference between two singleand independent results obtained by different operators work-ing in different laboratories on identical test material would, inthe long run, in the normal and correct operation of this testmethod, exceed 0.9 C only in one case in t
47、wenty.12.2 BiasBecause there are no liquid hydrocarbon mix-tures of known freezing point, which simulate aviation fuels,bias cannot be established.12.3 Relative BiasThe results for all the samples from theinterlaboratory program5were examined for biases relative toTest Method D2386 and IP 16. A syst
48、emic bias was observedand is quantified with the following equation:D2386 and IP 16 5 X 2 0.347 (1)where:D2386 and IP 16 = mean of the result tested by D2386 andIP 16.X = mean of the result tested by this testmethod (D7153).12.3.1 As example: For a D2386 and IP 16 result of 60 C,the result from this
49、 test method is 59.65 C , or 0.347 Cwarmer than the D2386 and IP 16 result.12.3.2 However, the relative bias is within the reproducibil-ity of both test methods.12.3.3 The cross method reproducibility (Rxy), identified inthe research report,5between this test method and Test MethodD2386 is 1.9. (See research report5for further information onrelative bias and the methods used to derive them.)12.4 The precision statements were derived from a 2003interlaboratory cooperative test prog
