1、Designation: D3941 90 (Reapproved 2007)D3941 14Standard Test Method forFlash Point by the Equilibrium Method With a Closed-CupApparatus1This standard is issued under the fixed designation D3941; the number immediately following the designation indicates the year oforiginal adoption or, in the case o
2、f 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.This standard has been approved for use by agencies of the U.S. Department of Defense.INTRODUCTIONTest Met
3、hods D56 and D93 describe procedures using the Tag Closed Tester and the Pensky-Martens Tester, respectively. Both test methods depend on a definite rate of temperature increase tocontrol the precision of the test method. The rate of heating may not in all cases give the accuracyexpected because of
4、low thermal conductivity of certain materials. To reduce this effect, ISO/TC 35,Paints and Varnishes, and ISO/TC 28, Petroleum Products and Lubricants, have issued ISO 1523 inwhich the heating rate is considerably slower. This test method is similar to ISO 1523, but usesstandard ASTM cups, style, an
5、d format. Due to the slower heating rate, the time required to make adetermination of a flash point is considerably longer than for Test Methods D56 and D93 but theaccuracy is improved.1. Scope Scope*1.1 This test method covers the determination of the flash point of liquids in which the specimen an
6、d the air/vapor mixture aboveit are approximately in temperature equilibrium.1.2 This test method is limited to a temperature range from 0 to 110C (32 to 230F).1.3 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.1.4 WarningMe
7、rcury has been designated by many regulatory agencies as a hazardous material that can cause centralnervous system, kidney and liver damage. Mercury, or its vapor, may be hazardous to health and corrosive to materials. Cautionshould be taken when handling mercury and mercury containing products. See
8、 the applicable product Safety Data Sheet (SDS) fordetails and EPAs website, http:/www.epa.gov/mercury/faq.htm, for additional information. Users should be aware that sellingmercury and/or mercury containing products into your state or country may be prohibited by law.1.5 This standard should be use
9、d to measure and describe the properties of material, products, or assemblies in response to heatand flame under controlled laboratory conditions and should not be used to describe or appraise the fire hazard or fire risk ofmaterials, products or assemblies under actual fire conditions. However, res
10、ults of this test may be used as elements of a fire riskassessment which takes into account all of the factors which are pertinent to an assessment of the fire hazard of a particular enduse.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It
11、is 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:2D56 Test Method for Flash Point by Tag Closed Cup Tester1 This test method is under
12、the jurisdiction of ASTM Committee D01 on Paint and Related Coatings, Materials, and Applications and is the direct responsibility ofSubcommittee D01.21 on Chemical Analysis of Paints and Paint Materials.Current edition approved June 1, 2007Dec. 15, 2014. Published June 2007January 2015. Originally
13、approved in 1980. Last previous edition approved in 20012007 asD3941 90 (2001).(2007). DOI: 10.1520/D3941-90R07.10.1520/D3941-14.2 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume informatio
14、n, refer to the standardsstandards 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 adequatel
15、y 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 the official document.*A Summary of Changes section appears at the end of this standardCopyright ASTM Inter
16、national, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1D93 Test Methods for Flash Point by Pensky-Martens Closed Cup TesterE1 Specification for ASTM Liquid-in-Glass ThermometersE1137 Specification for Industrial Platinum Resistance ThermometersE2251 Specificati
17、on for Liquid-in-Glass ASTM Thermometers with Low-Hazard Precision LiquidsE2877 Guide for Digital Contact Thermometers2.2 ISO Standard:ISO 1523 Paints, varnishes, petroleum, and related productsDetermination of flash pointClosed cup equilibrium method33. Terminology3.1 Definitions:3.1.1 flash point,
18、 nthe lowest temperature corrected to a pressure of 760 mm Hg (101.3 kPa) (1013 millibars) at whichapplication of an ignition source causes the vapor of the specimen to ignite under specified conditions of test.4. Summary of Test Method4.1 A specimen is heated in a closed cup of standard design in a
19、 suitable liquid bath at the rate of 0.5C (1.0F) in not less than1.5 min so that the difference in temperature between the specimen in the cup and bath never exceeds 2.0C (3.5F). Flashdeterminations are made at intervals of not less than 1.5 min.5. Significance and Use5.1 This test method, using a s
20、low rate of heating, provides a uniform temperature throughout the specimen. The slow rate ofheating is necessary because of the low thermal conductivity of some liquids such as paints, resins, and related products, and alsobecause of the poor heat transfer by convection in high-viscosity products.
21、Since the specimen is being heated at a reduced rate,the longer time interval between each determination is necessary to reestablish after each flash test the saturation concentration ofvapor in the air space above the specimen.NOTE 1ISO 1523 is used in United Nations Recommendations for Transportat
22、ion of Dangerous Goods and in the International Civil AviationOrganization (ICAO) regulations and for similar regulations in the International Maritime Dangerous Goods (IMDG) code. Test Method D3941, whichis similar to ISO 1523, is used in the United States Department of Transportation (USDOT) regul
23、ations. The ICAO and IMDG codes are used fortransshipment of hazardous materials through the United States to other countries.6. Apparatus6.1 Test Cups, equipped with their lid as specified in Test Methods D56 (Tag) and D93 (Pensky-Martens). Remove the test cupassembly (including lid and specimen th
24、ermometer) from the Tag and Pensky-Martens apparatus to permit either to be used in aseparate water bath.6.1.1 If a stirrer is fitted to the test cup used, it shall operate during the heating period but must be stopped during the flashingdetermination. If the stirrer originally fitted to the test cu
25、p is removed, the aperture in the cover shall be securely plugged beforestarting the test.6.2 Liquid BathAny suitable liquid bath capable of being adjusted to the required temperature and of adequate heat capacityto meet the requirements of the test. A bath fitted with a stirrer and an adjustable th
26、ermostat is convenient (see 4.1).NOTE 2The bath should be fitted with a cover, especially when the specified temperature is above 160F.At about this temperature the inerting effectof the water vapor may prevent or delay the flashing of the liquid under test.6.3 ThermometersStandard thermometers as s
27、pecified in Test Methods D56 and D93. Alternative temperature measuringdevices are permitted providing they have a similar response time and meet the respective performance and immersion depthspecifications of thermometers listed in Specification E1. See Specifications E1137 and E2251, and Guide E28
28、77 when selectingalternative temperature measuring devices. One thermometer shall be used to measure the temperature of the water bath and oneshall be used for measuring the temperature of the specimen in the cup.NOTE 3The thermometers for the water bath should be mounted at the correct level of imm
29、ersion for which they are specified in Specification E1.6.4 Support, for holding the test cup in the liquid bath so that the cover and upper edge are horizontal and the cup is immersedin direct contact with the liquid in such a position that the level of the specimen in the cup is the same as that o
30、f the liquid in thebath.6.5 ShieldA three sided shield, open in front, each side 460 mm (18 in.) wide and 610 mm (24 in.) high, is recommended.7. Reagents and Materials7.1 Water or Mixture of Water and Ethylene Glycol (1 + 1) may be used as a bath liquid.3 Available from American National Standards
31、Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.D3941 1428. Preparation of Sample8.1 Obtain a representative sample of the product under test and keep in an airtight container.8.2 Because of the possibility of loss of volatile constituents, the sample should recei
32、ve only the minimum treatment to ensureuniformity. After removing the specimen, immediately close the sample container tightly to ensure that no volatile flammablecomponents escape from the container (otherwise a new sample may be necessary if further testing is required).8.3 Do not open containers
33、unnecessarily. Do not make transfers unless the sample temperature is at least 10C (20F) belowthe expected flash point, except for materials that are too viscous to be handled at that temperature. In these cases, transfer thespecimens at the lowest possible temperature at which the material can be a
34、ccurately measured into the cup.8.4 Discard samples in leaky containers.8.5 Do not store samples in plastic (polyethylene, polypropylene, etc.) bottles, since volatile material may diffuse through thewalls of the bottles.9. Preparation of Apparatus9.1 Support the cup and liquid bath on a level stead
35、y table. Unless tests are made in a draft-free room or compartment, surroundthe tester on three sides by the shield for protection from drafts. Tests made in a laboratory draft hood or near ventilators are notreliable.9.2 Adjust the temperature of the bath to 5C (10F) below the approximate flash poi
36、nt determined by Section 10.9.3 Carefully clean and dry the test cup, the cover, and the cup thermometer, and bring them to approximately the sametemperature as the bath liquid.10. Procedure10.1 Preliminary TestDetermine the approximate flash point of the material by one or more preliminary tests. S
37、ee 10.2through 10.7.10.2 Fill the test cup with the appropriate amount of specimen for the cup being used at a temperature that is at least 10C (20F)below the approximate flash point (10.1). (See 8.3 for viscous materials.) Remove any bubbles on the surface of the specimen.Wipe the inside of the cov
38、er with a clean cloth or absorbent tissue paper.10.3 Immediately after filling the test cup, place the cover in position and support the cup in the bath so that the cover ishorizontal and the cup is immersed in direct contact with the bath liquid and with the surface of the specimen at the same leve
39、las or below that of the liquid in the bath. Confirm that the bath is at a temperature 5C (10F) below the approximate flash point.10.4 Light the flame of the ignition device and adjust it to the size of a bead of diameter 4.0 mm (532 in.).10.5 As soon as the specimen has attained the same temperatur
40、e as the bath (that is, the starting temperature of the definitivetests), perform a flash point test by opening the slide, inserting and removing the test flame, and closing the slide again, over aperiod of 2.5 6 0.5 s. While the test flame is inserted, observe whether there is a flash.10.6 If ignit
41、ion occurs (Note 4), the initial temperature selected was too high. Repeat the complete procedure from 10.2 witha fresh specimen at a temperature about 5C (10F) lower.NOTE 4When the vapor mixture under test is near the flash-point temperature, application of the test flame may give rise to a halo; h
42、owever, theproduct is only deemed to have flashed if a comparatively large flame appears and propagates itself over the surface of the liquid. If a large blue flamedoes not appear as a flash, but instead a continuous luminous flame burns in the orifice when the slide is opened and the ignition flame
43、 introduced, thenthe flash point of the product is much lower than the test temperature.10.7 If no ignition occurs (Note 4), heat the bath at a rate such that the difference in temperature between the bath and thespecimen never exceeds 2C (3.5F). When the specimen has increased in temperature by 0.5
44、C (1F) (that is, after not less than1.5 min nor more than 5 min), repeat the ignition test, and if no ignition occurs, repeat the procedure until a temperature is reachedat which ignition occurs. Read to the nearest 0.5C (1F) the temperature indicated by the cup thermometer.10.8 Make two determinati
45、ons repeating the procedure from 10.2, using the flash point temperature determined in 10.7 as theinitial temperature. Correct each temperature reading for any known thermometer correction and record the result as the flash pointtemperature at the barometric pressure prevailing during the test. Reco
46、rd also the barometric pressure in millimetres of mercuryor kilopascals. Correct each flash point reading when the barometric pressure differs from 760 mm Hg (101.3 kPa). (see 11.1).Determine the mean of the corrected results of the two determinations.NOTE 5As volatile components are liable to be pr
47、esent in the products being tested, the total duration of the test should not exceed 1 h.11. Calculation of Correction for Barometric Pressure11.1 When the barometric pressure differs from 760 mm Hg (101.3 kPa) calculate the corrected flash point temperature Tbymeans of the following equation:D3941
48、143T 5F10.06 7602P! (1)5C10.03 7602P!5F10.42 101.32B!5C10.23 101.32B!where:F (C) = observed flash point, F (C) andP (B) = barometric pressure, mm of Hg (kPa).where:F (C) = observed flash point, F (C) andP (B) = barometric pressure, mm of Hg (kPa).12. Report12.1 Report the flash point (the mean of tw
49、o results) to the nearest 0.5C (1F) and the cup used in the test.13. Precision and Bias13.1 PrecisionISO reported the following:13.1.1 RepeatabilityTwo results, each the mean of two determinations, obtained by the same operator using the sameapparatus should be considered suspect if they differ by more than 2C (3.5F).13.1.2 ReproducibilityTwo results, each the mean of two determinations, obtained by operators in different laboratories shouldbe considered suspect if they differ by more than 3C (5F).13.2 BiasThe procedure
