1、Designation: D 7153 05IP 529An American National StandardStandard Test Method forFreezing Point of Aviation Fuels (Automatic Laser Method)1This standard is issued under the fixed designation D 7153; the number immediately following the designation indicates the year oforiginal adoption or, in the ca
2、se of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of the tem-perature below which solid hydrocarb
3、on crystals may form inaviation turbine fuels.1.2 This test method is designed to cover the temperaturerange of -80 to 20C; however, the interlaboratory studymentioned in 12.4 has only demonstrated the test method withfuels having freezing points in the range of -60 to -42C.1.3 The values stated in
4、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 standard to establish appro-priate safety and healt
5、h practices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D 2386 Test Method for Freezing Point of Aviation Fuels.D 4057 Practice for Manual Sampling of Petroleum andPetroleum ProductsD 4177 Practice for Automatic Sampling of Petr
6、oleum 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 cooling,disappear when the temperature of the fue
7、l 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, followed by controlled warmingand recording of tem
8、perature 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 oftest.Co = the specimen temperature at which
9、 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 specified conditions of test.4. Summary of Test Me
10、thod4.1 A specimen is cooled at a rate of 10 6 5C/min whilecontinuously being illuminated by a laser light source. Thespecimen is continuously monitored by optical crystal andopacity detectors for the first formation of solid hydrocarboncrystals. Once the hydrocarbon crystals are detected by bothset
11、s of optical detectors, the specimen is then warmed at a rateof 3 6 0.5C/min. When initial opacity in the specimendisappears, the specimen is then warmed at a rate of 12 6lC/min. The specimen temperature at which the last hydro-carbon crystals return to the liquid phase, as detected by thecrystal de
12、tector, is recorded as the freezing point.4.2 In certain circumstances, as measured by the apparatus,the specimen is reheated to approximately 10C, then cooled atthe rate in 4.1 until hydrocarbon crystals are detected by thecrystal detector. The specimen is then warmed at a rate of 12 61This test me
13、thod is under the jurisdiction of ASTM Committee D02 onPetroleum Products and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved July 1, 2005. Published July 2005.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontac
14、t ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards 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.1Copyright ASTM Int
15、ernational, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.lC/min, until the last hydrocarbon crystals return to the liquidphase. The specimen temperature at which the last hydrocar-bon crystals return to the liquid phase, as detected by thecrystal detector, is r
16、ecorded as the freezing point.5. Significance 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 o
17、fthe fuel in the aircraft tank normally decreases 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 p
18、oint.5.3 This test method expresses results to the nearest 0.1C,and it eliminates most of the operator time and judgmentrequired by Test Method D 2386.5.4 When a specification requires Test Method D 2386,donot substitute this test method or any other test method.6. Apparatus6.1 Automatic Apparatus4T
19、his apparatus consists of amicroprocessor-controlled 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 prov
20、ided in Annex A1.6.2 The apparatus shall be 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 te
21、mperature of thespecimen from -80 to +20C at a resolution of 0.1C andaccuracy of 0.1C.6.4 The apparatus shall be capable of cooling the specimenat a rate of 10 6 5C/min, heating the specimen at rates of 3 60.5C/min and 12 6 1C/min over the temperature range of -80to +20C.NOTE 1The apparatus describe
22、d is covered by 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, capab
23、le of injecting approximately 106 2 mL of the specimen, with a tip or an adapter tip that willfit the inlet of the test cell. A disposable 10-mL syringe with aLuer type cone connection has been found suitable.6.6 Waste Receiving Container, capable of collecting theoverflow when the specimen is injec
24、ted into the test cell. A400-mL standard glass beaker has been found suitable.7. Sampling7.1 Obtain a sample in accordance with Practice D 4057 orD 4177.7.2 At least 30 mL of sample is required for each test.8. Preparation of Apparatus8.1 Install the apparatus for operation in accordance withthe man
25、ufacturers instructions.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 ap
26、paratus, an aviationturbine fuel sample for which extensive data has been obtainedby Test Method D 2386 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.10. P
27、rocedure10.1 Draw 10 6 2 mL bubble-free portion of sample into asyringe. Connect the syringe to the inlet port (Fig. 1). Rinse thetest cell by injecting 10 6 2 mL of specimen into the test cell;the specimen excess will flow into the waste receiving con-tainer (Fig. 2)10.2 Rinse the test cell a secon
28、d time by repeating 10.1.10.3 Draw a 10 6 2 mL bubble-free portion of sample intoa syringe.4The sole source of supply of the 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. I
29、f you are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend. FIG. 1 Syringe Inserted in Inlet PortD715305210.4 Connect the syringe
30、 to the inlet port (Fig. 1). Dispensethe specimen into the test cell; the specimen excess will flowinto the waste receiving 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 inst
31、ructions. From this point through Section11, the apparatus automatically controls the procedure.10.5.1 Cool the specimen at a rate of 10 6 5C/min whilecontinuously illuminating with a polarized laser light source.Monitor the specimen continuously with two optical detectors,an opacity detector and a
32、crystal detector (Fig. 3), for the firstformation of solid hydrocarbon crystals.10.5.2 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 60.5C/min until the disappearance of the opaci
33、ty (Do)isdetected on the opacity detector. At that point, warm thespecimen at a rate of 12 6 lC/min while it is still monitoredby the crystal detector. When the disappearance of the lastcrystals is detected on the crystal detector, record the specimentemperature at which the last hydrocarbon crystal
34、s return to theliquid phase. Refer to A1.2.12 and Fig. A1.5 for detectioncurve 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) temperature,it is recorded as the freezing point
35、.FIG. 2 Waste Containerwhere:1 = Specimen chamber2 = Temperature probe3 = Specimen test cell4 freezing point; wax crystals5Supporting data (the results of the 2003 Interlaboratory Cooperative TestProgram ) have been filed atASTM International Headquarters and may be obtainedby requesting Research Re
36、port RR:D021572.D7153054ANNEX(Mandatory Information)A1. APPARATUS DETAILSA1.1 GeneralThe microprocessor controlled test appara-tus is described in A1.2 and illustrated in Fig. A1.1.A1.2 Test apparatus shall consist of sample inlet tubing,optical detectors, laser light source, specimen chamber, tem-p
37、erature sensor, cooling system, and heater system arranged ina configuration as shown in Fig. A1.1.A1.2.1 Test Cell, comprised of sample inlet tubing, opticaldetectors, laser light source, specimen chamber, temperaturesensor, cooling device, and heater arranged in a configurationas shown in Fig. A1.
38、2.A1.2.2 Specimen Chamber, comprised of an aluminumblock bored with a hole of 3.7 6 0.1 mm on a length of 22 62 mm. The minimum external dimensions of the aluminumblock will be 66 by 42 by 16 mm. See Fig. A1.2.A1.2.3 Temperature Sensor, capable of reading to 0.1Cover the range +20 to -80C with a max
39、imum error of 0.1C.The sensor shall be calibrated at intervals of not more than 12months, and the calibration certificate shall include correctionsof at least the temperatures of +20, -40, and -80C. The sensorshall be permanently embedded into the bottom of the speci-men chamber and located in a pos
40、ition to measure accuratelythe specimen temperature.A1.2.4 Cooling System, an integral cooling system, capableof controlling the specimen temperature within the range ofanticipated test temperatures with a 0.1C accuracy.A1.2.5 Heating System, coupled to the specimen chambercapable of controlling the
41、 specimen temperature within therange of anticipated test temperatures with a 0.1C accuracy.A1.2.6 Optical Detection SystemAn electronic opticalsystem for monitoring the specimen for the appearance/disappearance of hydrocarbon crystals. The wavelength of thelaser light source shall be 650 6 20nmwith
42、a3mWpower.The system shall be composed of a light transmitter and twolight receivers, the crystal detector and the opacity detector.Two filters to polarize the light shall be positioned at eachextremity of 3.7 mm bore of the specimen chamber describedin A1.2.2. The opacity receiver shall be located
43、at 6 + 0.5 mmfrom the extremity of the bore of the specimen chamber, on theemitter side with a 90 angle. The window of the opacitydetector shall be tangent with the 3.7 mm bore.NOTE A1.1When the specimen is a homogeneous liquid, the crystaland the opacity detector do not receive any light. The signa
44、ls received onthe crystal detector and the opacity detector are transmitted to a micro-processor system and analyzed. When hydrocarbon crystals appear in thespecimen, the light beam is scattered and signal are received on bothdetectors. A typical configuration is shown in Fig. A1.2.A1.2.7 Apparatus
45、Exterior InterfaceThe exact layoutmay vary; however, the following displays and push buttonsare recommended.Atypical apparatus (see Fig.A1.3) is shownas an example.A1.2.8 Display, gives an update of the specimen tempera-ture during the measurement and with different menus providesinformation on the
46、status of the apparatus. It shall display anappropriate message when the apparatus is idle and no fault isfound. At the end of a test, the result is displayed. It shall bepossible to display the scattered light level received by theoptical detectors. This information may be used by servicepersonnel
47、for troubleshooting purposes. It displays a diagnosticmessage if a fault is detected in any of the major componentsof the apparatus. Detailed explanation of the diagnostic mes-sages is available in the manufacturers service manual.A1.2.9 Menu Buttons, allow the operator to access to thedifferent men
48、us like the change of the temperature fromCelsius to Fahrenheit and vice versa; noting that the Celsiusscale is regarded as the standard.A1.2.10 Run Button, allows the operator to start the mea-surement sequence once the specimen is put inside the test.A1.2.11 Stop Button, allows the operator to sto
49、p the mea-surement sequence. Upon pressing this button, the apparatuswill immediately stop the measurement sequence and warm thespecimen to ambient temperature.A1.2.12 Testing Process Charts, only possible with anoutput device. An example of possible signal curves is shownon Fig. A1.5. The specimen temperature profile shown is notavailable for the operator, it is given in Fig. A1.5 for a betterunderstanding of the specimen cooling profiles. Each fuel andeach contamination will produce different detection curves.However, when the same type of sam
