1、Designation: D7397 10 (Reapproved 2016)D7397 17Standard Test Method forCloud Point of Petroleum Products and Liquid Fuels(Miniaturized Optical Method)1This standard is issued under the fixed designation D7397; the number immediately following the designation indicates the year oforiginal adoption or
2、, in the case of revision, 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. Scope Scope*1.1 This test method covers the determination of the cloud point of petroleu
3、m products and biodiesel fuels that are transparentin layers 40 mm in thickness by an automatic instrument.1.2 This test method covers the range of temperatures from 60 C to +20 C with temperature resolution of 0.1 C; however,the range of temperatures included in the 2006 interlaboratory cooperative
4、 test program only covered the temperature range of35 C to +12 C. See Section 13.1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.4 This standard does not purport to address all of the safety concerns, if any, associated
5、with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.1.5 This international standard was developed in accordance with internationally recognized principles on stan
6、dardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Organization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2D2500 Test Method for Cloud Point of Petroleum
7、Products and Liquid FuelsD4057 Practice for Manual Sampling of Petroleum and Petroleum ProductsD4177 Practice for Automatic Sampling of Petroleum and Petroleum ProductsD5773 Test Method for Cloud Point of Petroleum Products and Liquid Fuels (Constant Cooling Rate Method)2.2 Energy Institute Standard
8、s:3IP 219 Test Method for Cloud Point of Petroleum ProductsIP 446 Test Method for Cloud Point of Petroleum Products3. Terminology3.1 Definitions:3.1.1 biodiesel, nfuel comprising mono-alkyl esters of long-chain fatty acids derived from vegetable oils or animal fats,designated B100.3.1.1.1 Discussion
9、Biodiesel is typically produced by a reaction of vegetable oil or animal fat with an alcohol such as methanol or ethanol in thepresence of a catalyst to yield mono-esters and glycerin. The fuel typically may contain up to 14 different types of fatty acids thatare chemically transformed into fatty ac
10、id methyl esters (FAME).1 This test method is under the jurisdiction ofASTM Committee D02 on Petroleum Products, Liquid Fuels, and Lubricants and is the direct responsibility of SubcommitteeD02.07 on Flow Properties.Current edition approved April 1, 2016May 1, 2017. Published May 2016May 2017. Origi
11、nally approved in 2007. Last previous edition approved in 20102016 asD7397 10.D7397 10 (2016). DOI: 10.1520/D7397-10R16.10.1520/D7397-17.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume in
12、formation, refer to the standards Document Summary page on the ASTM website.3 Available from Energy Institute, 61 New Cavendish St., London, WIG 7AR, U.K., http:/www.energyinst.org.uk.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of
13、what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be considered
14、the official document.*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 States13.1.2 biodiesel blend (BXX), nblend of biodiesel fuel with petroleum-based diesel fuel designated B
15、XX, where XX is thevolume percentage (as a whole number without the percentage sign) of biodiesel.3.1.3 cloud point, nin petroleum products and biodiesel fuels, the temperature of a liquid specimen when the smallestobservable cluster of hydrocarbonwax crystals first occurs upon cooling under prescri
16、bed conditions.3.1.3.1 DiscussionThe cloud point occurs when the temperature of the specimen is low enough to cause hydrocarbonwax crystals to precipitate. Ina homogeneous liquid, the cloud is always noted first at the location in the specimen where the specimen temperature is the lowest.The cloud p
17、oint is the temperature at which the crystals first occur, regardless of their location in the specimen, and not afterextensive crystallization has taken place. The hydrocarbonwax crystals that precipitate at lower temperatures are typically, but notexcluded to, straight chain hydrocarbons commonly
18、called “wax crystals.”straight-chain hydrocarbons and lipids.3.2 Definitions of Terms Specific to This Standard:3.2.1 D2500/IP 219 equivalent cloud point, ntemperature of a specimen, in integers, calculated by applying a bias androunding the result to the next lower integer (see 12.2).3.2.1.1 Discus
19、sionThis test method produces results with 0.1 C resolution. Should the user wish to provide results with a similar format to TestMethod D2500, then this calculation can be performed (see 12.2). Some apparatus can perform this calculation automatically.3.2.2 automatic cloud point, ntemperature of a
20、specimen, when the appearance of the cloud is determined under the conditionsof this test method.3.2.2.1 DiscussionThe cloud point in this test method is determined by an automatic instrument using a miniaturized test receptacle equipped withtwo optical fibers, one to bring light into the test recep
21、tacle and the other to receive light scattered from the specimen.3.2.3 miniaturized optical method, nin cloud point test methods, test procedure using prescribed cooling rate, specimenreceptacle, and optical system for detection of crystal formation.3.2.3.1 DiscussionThe prescribed cooling rate is d
22、escribed in 4.1, the specimen receptacle is described in Annex A1, and the optical system for thedetection of crystal formation is described in Annex A1.3.2.4 Peltier device, nsolid state solid-state thermoelectric device constructed with dissimilar semiconductor materials andconfigured in such a wa
23、y that it will transfer heat to or away from a test specimen dependent on the direction of electric currentapplied to the device.44. Summary of Test Method4.1 Aspecimen is cooled by a Peltier device in a miniaturized specimen receptacle (A1.1.1) at a rate of 30 C65 Cmin, whilecontinuously being illu
24、minated by a light source (A1.1.4). The specimen is continuously monitored by an optical detector (A1.1.5)for the first appearance of a cloud of wax crystals. Once crystals are first detected, as manifested by an increase in scattered lightlevel received by the optical detector, the specimen is warm
25、ed at a rate of 15 C 6 5 Cmin. As soon as all the crystals havere-dissolved into the liquid specimen, warming is halted and the specimen is cooled again; but this time at a slower rate of 6 C6 3 Cmin. When crystals first appear under this slower cooling rate, the temperature of the specimen is recor
26、ded to 0.1 Cresolution as cloud point.5. Significance and Use5.1 The cloud point of petroleum products and biodiesel fuels is an index of the lowest temperature of their utility for certainapplications. Wax crystals of sufficient quantity can plug filters used in some fuel systems.5.2 Petroleum blen
27、ding operations require a precise measurement of the cloud point.4 The Peltier device is covered by a patent. Interested parties are invited to submit information regarding the identification of an alternative(s) to this patented item to theASTM International Headquarters. Your comments will receive
28、 careful consideration at a meeting of the responsible technical mittee,1 which you may attend.D7397 1725.3 This test method can determine the temperature of the test specimen at which wax crystals have formed sufficiently to beobserved as a cloud with a resolution of 0.1C.0.1 C.5.4 This test method
29、 provides results that are equivalent to Test Method D5773/IP 446. The temperature results of this testmethod have been found to be warmer than those of Test Method D2500/IP 219 by an average of 0.49 C; however, no samplespecific bias was observed.5.5 Similar to Test Method D5773/IP 446, this test m
30、ethod determines cloud point in a shorter period of time than Test MethodD2500/IP 219.NOTE 1In cases of samples with cloud points near ambient temperatures, time savings may not be realized.NOTE 2This test method eliminates most of the operator time required of Test Method D2500/IP 219.NOTE 3The onl
31、y utility required by the apparatus described in this test method is electricity with power consumption of approximately 20 W. Theelectric power can come from an alternating current source (wall receptacle) or direct current source such as a battery or a cigarette lighter plug in avehicle.NOTE 4The
32、apparatus described by this test method can be made much smaller and lighter than that of Test Methods D5773/IP 446 and D2500/IP219, allowing full portability.NOTE 5The apparatus used in the 2006 interlaboratory study weighed approximately 1 kg and occupied the space of a small lunch box. See Sectio
33、n13.6. Apparatus6.1 Automatic Apparatus4,5The automatic cloud point apparatus described in this test method consists of a test chambercontrolled by a microprocessor that is capable of controlling the heating and cooling of the test specimen, optically observing thefirst appearance of a cloud of wax
34、crystals and recording the temperature of the specimen described in detail in Annex A1.6.2 The apparatus shall be equipped with a specimen receptacle, optical detector, light source, optical fibers, digital display,Peltier device, and a specimen temperature measuring device.6.3 The Peltier device sh
35、all be capable of heating or cooling the test specimen at a rate of 3 C to 35 Cmin.6.4 The temperature measuring temperature-measuring device in the specimen receptacle shall be capable of measuring thetemperature of the test specimen from 60 C to +20 C at a resolution of 0.1 C.4NOTE 6The apparatus
36、described above is covered by patents. If you are aware of an alternative(s) to the patented items, please attach to your ballotreturn a description of the alternative(s). All suggestions will be considered by the committee.7. Reagents and Materials7.1 Disposable syringe that is capable of dispensin
37、g at least 10 mL 6 0.5 mL per full discharge of sample into the specimenreceptacle.NOTE 7The apparatus can also be connected to a sample supply line to receive new sample. The amount of sample required per analysis is the sameas that for the syringe injection procedure (that is, 20 mL 6 1.0 mL per a
38、nalysis). In such cases, a disposable syringe would not be needed.8. Sampling8.1 Obtain a sample in accordance with PracticesPractice D4057 or D4177.8.2 Samples of very viscous materials may be warmed until they are reasonably fluid before they are tested. However, no sampleshould be heated more tha
39、n absolutely necessary.8.3 The sample shall not be heated above 70 C. When the sample is heated above 70 C, allow the sample to cool below 70 Cbefore filtering or inserting into the apparatus.8.4 When moisture is present in the sample, remove the moisture by a method,method such as filtration throug
40、h dry, lint-freefilter paper,paper until the specimen is perfectly clear, but make such filtration at a temperature at least 14 C above the expectedcloud point.NOTE 8Moisture will be noticed in the sample as a separate phase or as a haze throughout the entire sample. Generally, a slight haze will no
41、t interferewith the detection of the wax cloud.9. Preparation of Apparatus9.1 Prepare the instrument for operation in accordance with the manufacturers instructions.9.2 Turn on the main power switch of the analyzer.5 The sole source of supply of the apparatus known to the committee at this time is P
42、hase Technology Miniature Cloud Point Analyzer available from Phase Technology,11168 Hammersmith Gate, Richmond, B.C., Canada V7A-5H8. If you are aware of alternative suppliers, please provide this information toASTM International Headquarters.Your comments will receive careful consideration at a me
43、eting of the responsible technical committee,1 which you may attend.D7397 17310. Calibration and Standardization10.1 Ensure that all of the manufacturers instructions for calibrating, checking, and operating the apparatus are followed.10.2 A sample with a mutually agreed upon cloud point can be used
44、 to verify performance of the apparatus.11. Procedure11.1 Draw 10 mL 6 0.5 mL of bubble-free sample into a new disposable syringe. Connect the syringe to the inlet port, andinject the full charge of sample into the test receptacle. The specimen excess will flow into a waste-receiving container.11.2
45、Draw another 10 mL6 0.5 mL of bubble-free sample into the syringe. Connect the syringe to the inlet port, and inject thefull charge of sample into the test receptacle. The specimen excess will flow into a waste-receiving container. The total amountof sample (that is, 20 mL 6 1.0 mL) is sufficient in
46、 quantity to flush out any previous sample in the specimen receptacle and fillit with the fresh sample.NOTE 9Follow manufacturers instructions for sample injection if the specimen receptacle is connected to a sample supply line as described in Note7.11.3 Start the operation of the apparatus accordin
47、g to the manufacturers instructions. From this point on, the apparatusautomatically controls the procedure.11.4 Cool the sample at a rate of 30 C 6 5 Cmin, while continuously illuminating the sample with the light source. Monitorthe specimen continuously with the optical detector. Once crystals are
48、first detected, as manifested by an increase in light levelreceived by the optical detector, warm the specimen at a rate of 15 C 6 5 Cmin. As soon as all the crystals have re-dissolvedinto the liquid specimen in accordance with this test method, stop the warming and cool the specimen again at a slow
49、er rate of6 C 6 3 Cmin. When crystals first appear under this slower cooling rate, record the temperature of the specimen as the cloudpoint.11.5 The measurement is automatically terminated once the cloud point is detected.11.6 When the measurement is complete, the cloud point value per Test Method D7397 will be displayed by the apparatus.12. Calculation or Interpretation of Results12.1 Report the temperature recorded in 11.6 as the automatic cloud point Test Method D7397.12.2 When specified, corre
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