1、Designation: D1177 07 D1177 12Standard Test Method forFreezing Point of Aqueous Engine Coolants1This standard is issued under the fixed designation D1177; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 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 Scope*1.1 This test method covers the determination of t
3、he freezing point of an aqueous engine coolant solution in the laboratory.NOTE 1Where solutions of specific concentrations are to be tested, they shall be prepared from representative samples as directed in Practice D1176.Secondary phases separating on dilution need not be separated.NOTE 2These prod
4、ucts may also be marketed in a ready-to-use form (prediluted).1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It i
5、s the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use.2. Referenced Documents2.1 ASTM Standards:2D1176 Practice for Sampling and Preparing Aqueous Solutions of Engine Coolants or Ant
6、irusts for Testing PurposesE1 Specification for ASTM Liquid-in-Glass Thermometers3. Terminology3.1 Definitions:3.1.1 freezing pointthe temperature at which crystallization begins in the absence of supercooling, or the maximumtemperature reached immediately after initial crystal formation in the case
7、 of supercooling, or the temperature at which solidcrystals, formed on cooling, disappear when the temperature of the specimen is allowed to rise.4. Summary of Test Method4.1 This test method involves the determination of the time-temperature curve prior to freezing and the determination of thehoriz
8、ontal or flattened portion of the freezing curve. The freezing point is taken as the intersection of projections of the coolingcurve and the freezing curve. If the solution supercools, the freezing point is the maximum temperature reached after supercooling.5. Significance and Use5.1 The freezing po
9、int of an engine coolant indicates the coolant freeze protection.5.2 The freezing point of an engine coolant may be used to determine the approximate glycol content, provided the glycol typeis known.6. Apparatus6.1 Freezing Point Apparatus, shown assembled in Fig. 1, consisting of the following:6.1.
10、1 Cooling Bath, in which the refrigerant is contained, consisting of a standard 1.9-L (2-qt) Dewar flask. The flask may besilvered or unsilvered, and is supported in a close-fitting container. A pad of glass wool is placed in the bottom of the flask to protectit from damage by tip of freezing tube.1
11、 This test method is under the jurisdiction of ASTM Committee D15 on Engine Coolants and Related Fluids and is the direct responsibility of Subcommittee D15.03 onPhysical Properties.Current edition approved April 1, 2007Oct. 1, 2012. Published April 2007November 2012. Originally approved in 1951. La
12、st previous edition approved in 20052007 asD1177 05.D1177 07. DOI: 10.1520/D1177-07.10.1520/D1177-12.2 For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards
13、 Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, A
14、STM 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 the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM International, 100 Barr Harbor Drive, P
15、O Box C700, West Conshohocken, PA 19428-2959. United States16.1.2 Freezing Tube3 consisting of a 200-mL (6.8-oz.) unevacuated, unsilvered Dewar flask. The tube is closed by a cork havinga central hole for the thermocouple or thermometer, a second hole placed to one side for passage of the stirring r
16、od, and a thirdhole for introducing wire for seeding at appropriate time.6.1.3 Stirring Mechanism, consisting of a five-coil stirrer formed of stainless steel wire 1.6 mm (116 in.) in diameter. The coilsare so spaced that, in the extreme upward position during operation, no coils are exposed above t
17、he surface of the sample. Thestirrer is agitated by means of an ordinary windshield wiper motor or other motor devices, operating through suitable linkages soas to provide linear motion of the stirrer. The length of the stroke is adjusted so that the coil just clears the bottom of thefreezing-point
18、tube at low point of the stroke.6.1.4 Temperature MeasurementA resistance thermometer or a multi-junction copper-constantan thermocouple may be usedwith suitable measuring instruments, providing these give an over-all sensitivity of 0.1C (0.2F). The instrument shall becalibrated before each series o
19、f determinations by using suitable reference standards. Platinum resistance thermometers have beenadopted as a standard by the National Institute of Standards and Technology (NIST) and are recommended for this standard.NOTE 3ASTM Coolant Freezing Point Temperature Measuring Instruments having a rang
20、e from 37 to + 2C (35 to + 35F) or 54 to 15C(65 to + 5F) and conforming to the requirements for Thermometers 75F or 76F as prescribed in Specifications E1, may be used where less accuracyis acceptable provided reference standards are used for calibration purposes.7. Refrigerant7.1 The refrigerant sh
21、all consist of solid carbon dioxide in alcohol or in other suitable bath liquids.3 For routine work, a tube with a seeding tip as described in the paper by R. E. Mallonee and F. L. Howard, “The Determination of Freezing Point of Engine Antifreeze,”in the February 1951 issue of the ASTM Bulletin may
22、be used. (See Fig. 2.)FIG. 1 Assembly of Freezing Point ApparatusD1177 122NOTE 4A layer of dry ice, at least 13 mm (12 in.) thick, must be maintained in the bottom or on the top of the cooling bath during a determination,depending on the bath liquid used. Adequate precautions should be taken against
23、 fire hazards or toxic effects of bath liquids, or both.7.2 Liquid nitrogen may be used as the refrigerant when the freezing point of the coolant is 46C (50F) or lower.(WarningThe liquid nitrogen should be discarded after each days use to avoid the possibility of explosion due to dissolvedoxygen and
24、 inadvertent mixing with organic coolant materials.)8. Procedure8.1 Assemble the apparatus as shown in Fig. 1, with no refrigerant and no sample of coolant yet in place. Check the operationof the stirring mechanism after assembly to be sure that all parts operate freely.8.2 Fill the Dewar flask surr
25、ounding the freezing tube with the refrigerant liquid, adding pieces of solid carbon dioxide fromtime to time to maintain conditions mentioned in Note 4. Temporarily remove the stopper from the freezing tube and introduce75 to 100 mL (2.65 to 3.4 oz.) of the sample.NOTE 5The sample may be precooled
26、to approximately 8C (15F) above the expected freezing point before introducing it into the freezing tube.8.3 Start the stirrer and adjust it to operate at 60 to 80 strokes per min (Note 6). As soon as stirring is begun, observe and recordthe temperature at regular intervals of time. Electronic data
27、acquisition systems may also be used in place of manual observationand recording. As the expected freezing point is approached, the time intervals should be quite short, 15 s if possible. At theexpected freezing point, seeding should be started to prevent supercooling. This can be accomplished by in
28、troducing a wire whichhas a small portion of the solution being tested frozen on its tip. It is most convenient to freeze this solution in a small test tubeinserted directly into the cooling bath.NOTE 6A stroke is considered as a complete cycle of one upward and one downward motion of the stirrer.NO
29、TE 7The cooling rate must be less than 1C (2F)/min at the time the solution is seeded.8.4 Continue temperature readings at regular intervals for at least 10 min after the apparent freezing point.9. Report9.1 Plot the observed temperature against time on rectangular coordinate paper. Where the curve
30、shows a definite flat or plateauduring freezing, the freezing point is taken as the intersection of projections of the cooling curve and the flat or horizontal plateauportion of the freezing curve (see Fig. 32(a). If the solution supercools, the freezing point is the maximum temperature reachedimmed
31、iately after supercooling (see Fig. 32(b).NOTE 8The amount of supercooling should be held to a minimum. If the supercooling exceeds 1C (2F) the test should be rejected.10. Precision and Bias10.1 Precision and Bias results are as follows:4C FRepeatability of Test for a Given Analyst 0.17 0.31Intermed
32、iate Precision of Test for a Given Laboratory 0.88 1.58Reproducibility of Test Across Laboratories 1.30 2.3411. Keywords11.1 aqueous engine coolants; engine coolants; engine coolants; freezing point4 A research report is available from ASTM headquarters. Request RR:D15-1010.FIG. 32 Time-Temperature
33、Cooling Curves for Determining the Freezing Point of an Engine CoolantD1177 123SUMMARY OF CHANGESSubcommittee D15.03 has identified the location of the selected changes to this standard since the last issue(D1177-07) that may impact the use of this standard.(1) Updated 8.3.(2) Modified Fig. 1.(3) Re
34、moved Fig. 2.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of suc
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37、 ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the
38、aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).FIG. 2 Bottom of Freezing Tube Showing Seeding TipD1177 124
