1、Designation: D7153 05 (Reapproved 2010)IP 529Standard 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 revisio
2、n, the year 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.1. Scope1.1 This test method covers the determination of the tem-perature below which solid hydrocarbon crystals ma
3、y 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 SI units are t
4、o 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 health practices an
5、d 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 ProductsD4177 Practice for Automatic Sampling of Petroleum andPetroleum
6、 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 fuel is allowed to ri
7、seunder 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 temperature at which
8、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 the appearance of
9、opacity 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 Method4.1 A specimen
10、 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 bothsets of optical detec
11、tors, 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 detector, is recorde
12、d 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 6lC/min, until the last hydrocar
13、bon crystals return to the liquid1This test method 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 May 1, 2010. Published May 2010. Originallyapproved in 2005. Last
14、previous edition approved in 2005 as D715205. DOI:10.1520/D7153-05R10.2For 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 standards Document Summary page onthe ASTM
15、 website.3Annual Book of IP Standards Methods, Vol 1. Available from Energy Institute,61 New Cavendish St., London, WIG 7AR, U.K.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.phase. The specimen temperature at which the last hydroc
16、ar-bon crystals return to the liquid phase, as detected by thecrystal detector, is recorded 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 sys
17、tem of the aircraft,can restrict the flow of fuel through filters. The temperature ofthe 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 temperat
18、ure.5.2 Petroleum blending operations require precise measure-ment of the freezing point.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 D2386.5.4 When a specification requires Test Method D2386,donot substitu
19、te this test method or any other test method.6. Apparatus6.1 Automatic Apparatus4This 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
20、 the temperature of the specimen. A detailed descrip-tion of the apparatus is provided 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 temper
21、ature measuring device in the specimenchamber shall be capable of measuring the temperature 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
22、 12 6 1C/min over the temperature range of -80to +20C.NOTE 1The apparatus described 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 so
23、ftware version used in this apparatus is version V 5.3.6.5 Standard Syringe, capable 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
24、 Receiving Container, capable of collecting theoverflow when the specimen is injected into the 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. Preparati
25、on of Apparatus8.1 Install the apparatus for operation in accordance withthe manufacturers 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 an
26、doperation of the apparatus are followed.9.2 To verify the performance of the apparatus, an aviationturbine 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
27、verification materials can also beprepared from intra-company crosschecks.10. Procedure10.1 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 fl
28、ow into the waste receiving con-tainer (Fig. 2)10.2 Rinse the test cell a second time by repeating 10.1.10.3 Draw a 10 6 2 mL bubble-free portion of sample intoa syringe.10.4 Connect the syringe to the inlet port (Fig. 1). Dispensethe specimen into the test cell; the specimen excess will flowinto th
29、e waste receiving container (Fig. 2). Leave the syringeconnected to the sample inlet for the entire duration of the test.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, 14
30、653 CARPIQUET Cedex, France. If 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 PortD7
31、153 05 (2010)210.5 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 at a rate of 10 6 5C/min whilecontinuously illuminating with a polarized laser light source.
32、Monitor the specimen continuously with two optical detectors,an opacity detector and a 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 de
33、tector, warm the specimen at a rate of 3 60.5C/min until the disappearance of the opacity (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
34、 crystal detector, record the specimentemperature at which the last hydrocarbon crystals 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 record
35、ed temperature is warmer than the (Cd) 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 the appa-ratus, perform a second test cycle as follows in 10.6.FIG. 2 Waste Conta
36、inerwhere: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 Report RR:D02-1572.D7
37、153 05 (2010)4ANNEX(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-perature se
38、nsor, 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. A1.2.A1.2.2 S
39、pecimen 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 maximum error
40、 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 position to m
41、easure 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 specimen
42、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 20nmwitha3mWpower.
43、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 at 6 + 0.5
44、 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 signals receive
45、d 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 Exterior I
46、nterfaceThe 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 status of
47、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 for troubl
48、eshooting 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 menus like th
49、e 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 stop 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
