1、Designation:D332194 (Reapproved 2007) Designation: D3321 12Standard Test Method forUse of the Refractometer for Field Test Determination of theFreezing Point of Aqueous Engine Coolants1This standard is issued under the fixed designation D3321; the number immediately following the designation indicat
2、es the year oforiginal adoption or, 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. Scope1.1 This test method covers the use of a portable
3、 refractometer for determining the approximate freezing protection providedby ethylene and propylene glycol-based coolant solutions as used in engine cooling systems and special applications.NOTE 1Some instruments have a supplementary freezing protection scale for methoxypropanol coolants. Others ca
4、rry a supplemental scale calibratedin density or specific gravity readings of sulfuric acid solutions so that the refractometer can be used to determine the charged condition of lead acidstorage batteries.1.2 The values stated in SI units are to be regarded as the standard. The values given in paren
5、theses 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 is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitation
6、s prior to use.2. Referenced Documents2.1 ASTM Standards:2D1177Test Method for Freezing Point of Aqueous Engine CoolantsD1177 Test Method for Freezing Point of Aqueous Engine CoolantsE177 Practice for Use of the Terms Precision and Bias in ASTM Test MethodsE691 Practice for Conducting an Interlabora
7、tory Study to Determine the Precision of a Test Method3. Summary of Test Method3.1 These coolant testers3are critical-angle refractometers designed for rapid, approximate measurement of ethylene andpropylene glycol coolant freezing point protection. Only a few drops of test solution are required. So
8、me testers automaticallycorrect for ambient air temperature and the temperature of the solution being tested. The instrument is rugged, simple to read, andeasy to clean and maintain.3.2 The coolant freezing point readings are taken at points where the dividing line between light and dark crosses the
9、 scales.Some refractometers have a coolant scale for indicating the freezing point of aqueous ethylene glycol coolants only, while otherrefractometers also have a scale for indicating the freezing point of aqueous propylene glycol coolants. The range of the scalesvaries from one device to another.3.
10、3 Freezing point measurements are concentration-related values and are in turn directly related to refractive index. It has beenempirically determined that freezing point measurements are accurate within 1C (2F).4. Significance and Use4.1 This practice is commonly used by vehicle service personnel t
11、o determine the freezing point, in degrees Celsius orFahrenheit, of aqueous solutions of commercial ethylene and propylene glycol-based coolant. A durable hand-held refractometeris available that reads the freezing point, directly, in degrees Celsius or Fahrenheit, when a few drops of engine coolant
12、 are properlyplaced on the temperature-compensated prism surface of the refractometer. This refractometer is for glycol and water solutions,and is not suitable for other coolant solutions.4.2 The hand-held refractometer should be calibrated before use (see Section 7).1This test method is under the j
13、urisdiction of ASTM Committee D15 on Engine Coolants and Related Fluids and is the direct responsibility of Subcommittee D15.03 onPhysical Properties.Current edition approved Nov. 15, 2007. Published November 2007. Originally approved in 1974. Last previous edition approved in 2002 as D332194(2002).
14、 DOI:10.1520/D3321-94R07.Current edition approved April 1, 2012. Published May 2012. Originally approved in 1974. Last previous edition approved in 2007 as D3321 94(2007). DOI:10.1520/D3321-12.2For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at s
15、erviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.3Coolant testers are available from Leica Inc., P.O. Box 123, Buffalo, NY 14240 and Misco Products, 3401 Virginia Rd., Cleveland, OH 44122.1This document is not an AS
16、TM 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, ASTM recommends that users consult prior editions as appropriate. In a
17、ll cases only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.4.3 Care must be taken to use the correct glycol freezing point scale for
18、the glycol type being measured. Use of the wrong glycolscale can result in freezing point errors of 18 and more degrees Fahrenheit.4.4 Ethylene glycol/propylene glycol mixtures will result in inaccurate freezing point measurements using either freezing pointscale.5. Interferences5.1 Interference can
19、 occur if the mixture is contaminated or if the prism surface is not clean. The presence of other glycols suchas diethylene glycol in small amounts will not cause interference.6. Apparatus6.1 The hand-held critical angle refractometer is a rugged die-cast portable instrument that is covered with a h
20、igh-impact plasticto minimize damage to the eyepiece lens if dropped. A polished glass prism is opposite the viewing end. A hinged plastic coveris moved over the prism (sampling end) to allow for even sample distribution and prevent liquid sample spillage during the test.No eyepiece or prism adjustm
21、ents are required for sample testing.6.2 The telescopic recessed eyepiece is located at one end and the graduated, translucent prism on the opposite end (see Fig.1).7. Calibration7.1 Calibration of these coolant testers should periodically be verified by testing a water sample in accordance with the
22、procedure outlined in Section 8.7.2 If the sample tested deviates from 0C (+32F) the coolant tester is out of calibration and should be recalibrated.7.3 This calibration test is best performed with the coolant tester and water sample at room temperature. If the instrument usedis designed to be autom
23、atically temperature compensated, work within the stated temperature-compensated range.8. Procedure8.1 CleaningBefore using, swing back the plastic cover at the slanted end of the tester exposing both the measuring windowand the bottom of the plastic cover. Wipe both clean and dry with tissue or cle
24、an soft cloth. Close the plastic cover (see Fig. 2).8.2 Testing Coolant SolutionCommercial instruments are usually equipped with a small suction pipet for sampling solutions.This tube should be used to remove a sample (from below the coolant surface) and eject a few drops on the measuring window(see
25、 Fig. 3). Flush suction pipet with test solution before withdrawing sample for testing.8.3 Readings:8.3.1 Point the instrument toward any light source (for example, a headlight) and look into the eyepiece (Fig. 4).8.3.2 The freeze point protection is the point where the dividing line between light a
26、nd dark (edge of the shadow) crosses thescale; read the scale marked for the type of coolant being tested (see Fig. 5).NOTE 2Tester temperature scales are reversed from standard thermometer scales. Below zero readings are located on upper half of scale.8.3.3 A little experience is required to obtain
27、 the best contrast between the light and dark portions of the scale. Tilt theinstrument towards the light source until best results are obtained.NOTE 3Refractometer freezing point scales are available in C and F for both propylene glycol and ethylene glycol-base coolants.8.3.4 If the edge of the sha
28、dow is not sharp, the measuring surfaces were not sufficiently well cleaned or dried or an insufficientamount of coolant sample was used. Clean and dry the window. Conduct a new test.NOTE 4Oil contamination will reduce the sharpness of the dividing line.8.3.5 A completely dark scale indicates insuff
29、icient coolant sample was used. Completely light scale indicates that the coolantfreezing point is below the scale range.8.3.6 There is a danger of the loss of water vapor from the mixture, due to the small amount of sample required, if the solutionis sampled at elevated temperatures. Under these ci
30、rcumstances the reading should be taken immediately. More accurate readingsare obtained when testing at ambient temperature.9. Precision and Bias9.1 The precision of this test method is based on an interlaboratory study conducted in 2011. Twelve laboratories tested fourFIG. 1 Hand-Held Critical Angl
31、e RefractometerD3321 122FIG. 2 CleaningNOTE 1Do not remove clear plastic pump from tester. Release tip ofpump from tester housing and insert into radiator filler neck or coolantreservoir tank. Be sure to insert well below level of fluid. Press and releasebulb to draw up a sample of coolant. Eject th
32、e liquid to flush the tube.Repeat filling to obtain sample. Bend plastic tube around tester so that tipcan be inserted in cover plate opening. Eject a few drops of coolant ontomeasuring surface by pressing bulb. Ensure that the sample is notcontaminated with oil.FIG. 3 SamplingD3321 123different mat
33、erials for two different properties. Each “test result” represents an individual determination. Each laboratory reportedtriplicate test results for each analysis. Practice E691 was followed for the design and analysis of the data; the details are givenin RR:D15-1032.49.1PrecisionThe precision of thi
34、s test method, as determined by the examination of the interlaboratory test results, is asfollows:9.1.1For different test operators using the specified equipment and the procedure in Section 8, the results should not vary morethan 0.5C (1.0F) when the temperature of the coolant solution is 24C (75F)
35、 or more than 1C (2F) from the average valuewhen the coolant solution temperature is 82C (180F).9.1.2Table 1 lists the freezing points obtained by Test Method D1177 and the refractometer for representative glycolantifreeze/coolant mixtures and water.9.1.1 Repeatability Limit, rTwo test results obtai
36、ned within one laboratory shall be judged not equivalent if they differ bymore than the r value for that material; r is the interval representing the critical difference between two test results for the samematerial, obtained by the same operator using the same equipment on the same day in the same
37、laboratory.9.1.1.1 Repeatability limits are listed in Tables 1 and 2.9.1.2 Reproducibility Limit, RTwo test results shall be judged not equivalent if they differ by more than the R value for thatmaterial; R is the interval representing the critical difference between two test results for the same ma
38、terial, obtained by differentoperators using different equipment in different laboratories.9.1.2.1 Reproducibility limits are listed in Tables 1 and 2.4Supporting data are available from ASTM Headquarters. Request RR:D15-10132.FIG. 4 ReadingFIG. 5 Tester Temperature ScaleD3321 1249.1.3 The above ter
39、ms (repeatability limit and reproducibility limit) are used as specified in Practice E177.9.1.4 Any judgment in accordance with statements 9.1.1 and 9.1.2 would have an approximate 95% probability of being correct.9.2 BiasSince there is no acceptable reference material suitable for determining the b
40、ias for this test method, bias has not beendetermined. At the time of the study, there was no accepted reference material suitable for determining the bias for this testmethod, therefore no statement on bias is being made.9.3 The precision statement was determined through statistical examination of
41、288 results, from twelve laboratories, on fourdifferent materials.10. Keywords10.1 engine coolants; freezing point; refractometerTABLE 1 Comparison of Freezing PoinEts bhy Rlefrane Glyctometer versus Test Method D1177l (EG), %Base GlycolMixturerialFreezing Point 50/50Aqueous SolutionMaterial Aveous
42、SolutionRefractometer, C (F)Test Method D1177,C (F)Refrage, xARepeatabilityC (F)95 % Ethylene glycol 33; 34 (28; 29) 34 (30)95 % EStandard Deviation,Sr33; 34 (28; 29) 34 (30)5%H2O5 % HReproducibilityStandard Deviation, SRRepeatabilityLimit, rReproducibilityLimit, R90 % Ethylene glycol 34; 35 (30; 31
43、) 34; 35 (30;31)Sample No. 1:Ethylene Glycolin Water50.50 0;31)5 % Propylene glycol 0.00 2.805 % Propylene glycol.00 1.00 0.00 2.805%H2O90 % Ethylene glycol 34; 34 (30; 30) 35 (31)90 % Ethylene glycol5 % Diethylene glycol5%H2O 0.47 1.75Sample No. 2:Conventional FullyFormulated EG49.53 0.17 0.63 0.47
44、 1.7590 % Ethylene glycol 34; 34 (29; 29) 34 (30)2.5 % Propylene glycol 0.17 0.87 0.47 2.43Sample No. 3:ELC #150.44 0.17 0.87 0.47 2.432.5 % Diethylene glycol5%H2O0.29 0.83 0.81 2.32Sample No. 4:ELC #251.58 0.29 0.83 0.81 2.32AThe average of the laboratories calculated averages.TABLE 2 Freeze Point,
45、 CMaterialAverage, xARepeatabilityStandard Deviation, SrReproducibilityStandard Deviation, SRRepeatabilityLimit, rReproducibilityLimit, RSample No. 1:Ethylene Glycolin Water-35.67 0.33 2.09 0.93 5.84Sample No. 2:Conventional FullyFormulated EG-32.92 0.47 1.86 1.32 5.21Sample No. 3:ELC #1-35.03 0.37
46、1.85 1.04 5.17Sample No. 4:ELC #2-38.44 0.29 2.05 0.81 5.74AThe average of the laboratories calculated averages.D3321 125ASTM 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 expres
47、sly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif not revised,
48、 either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may at
49、tend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the 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 aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through t
