1、Designation: E438 92 (Reapproved 2018)Standard Specification forGlasses in Laboratory Apparatus1This standard is issued under the fixed designation E438; 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 U.S. Department of Defense.1. Scope1.1 This specification covers the glasses commonly us
3、ed tomanufacture laboratory glass apparatus.1.2 This international standard was developed in accor-dance with internationally recognized principles on standard-ization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recom-mendations issued by the W
4、orld Trade Organization TechnicalBarriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2C225 Test Methods for Resistance of Glass Containers toChemical AttackC338 Test Method for Softening Point of GlassC598 Test Method for Annealing Point and Strain Point ofGlass by Beam Bendi
5、ngC729 Test Method for Density of Glass by the Sink-FloatComparatorE228 Test Method for Linear Thermal Expansion of SolidMaterials With a Push-Rod Dilatometer3. Classification3.1 Three types are included, as follows:3.1.1 Type I, Class AA low-expansion borosilicate glass.3.1.2 Type I, Class BAn alum
6、ino-borosilicate glass.3.1.3 Type IIA soda-lime glass.4. Chemical Requirements4.1 The Type I, Class A and B glasses shall have the majorconstituents and comply with the restrictions on trace constitu-ents given in Table 1. The major constituents will be varied tomaintain the physical requirements as
7、 shown.4.2 Suitable Type II glasses may vary somewhat in chemicalcomposition and still meet essential physical requirements.Two such compositions are shown in Table 2; both are readilyavailable and are used for laboratory apparatus.5. Physical Requirements5.1 The physical requirements for glasses sh
8、all be as pre-scribed in Table 3. The tolerances listed in Table 3 must be onthe published values of the manufacturers specific glasscompositions.6. Keywords6.1 glasses; laboratory1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibil
9、ity of Subcommittee E41.01 onLaboratory Ware and Supplies.Current edition approved Jan. 1, 2018. Published January 2018. Originallyapproved in 1971. Last previous edition approved in 2011 as E438 92 (2011).DOI: 10.1520/E0438-92R18.2For referenced ASTM standards, visit the ASTM website, www.astm.org,
10、 orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United StatesThis internationa
11、l standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
12、1TABLE 3 Physical RequirementsNOTE 1Values in parentheses are the permissible ranges of nominal values and the tolerances shown are permitted on the nominals published by eachmanufacturer.Property Type I, Class A Type I, Class B Type II Glass ASTM Test MethodLinear coefficient of expansion, 0 to 300
13、C, cm/cmC 107(3233) (4856) (9093) E2281.5 2 2Annealing point, C 560 574 (520540) C59810 10 10Softening point, C (815820) (783799) (700720) C33810 10 10Density, annealed, g/cm3(2.232.24) (2.332.36) (2.472.53) C729A0.02 0.02 0.02Chemical durability, titration equivalent of: 0.02N H2SO4/10 g of glass,m
14、ax, ml1.0 1.0 9.5 C225 (Method P-W)ASee Day, R. K., Glass Research Methods, Industrial Publications, Inc., Chicago, IL, 1953, pp. 98100.TABLE 1 Chemical Requirements of Type I GlassesType I, Class A,weight %Type I, Class B,weight %Major constituents, approximate:SiO281 73B2O313 10Al2O327BaO see belo
15、w 02CaO see below 1Na2O46K2O see below 1Trace constituents, max:As2O2plus Sb2O30.005 0.1PbO 0.1 0.1MgO 0.1 0.3ZnO 0.1 0.1CaO 0.1 see aboveK2O 0.75Asee aboveAll other constituents, max 0.2 1.0AEach manufacturer must publish the maximum percentage in his glass becausecertain limited applications requi
16、re a level under 0.1 %.TABLE 2 Chemical Requirements of Type II GlassesComposition A,weight %Composition B,weight %Major constituents, approximate:SiO268 72B2O32 .Al2O332BaO 2 .CaO 5 5MgO 4 4Na2O116K2Trace constituents, max:As2O3+Sb2O3Pb O0.10.10.10.1All other constituents, max 1.0 1.0E438 92 (2018)
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18、e 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, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standa
19、rdsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Commit
20、tee 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 the ASTM website(www.astm.org). Permission rights to photocopy the standard may also be secured from the Copyright Clearance Center, 222Rosewood Drive, Danvers, MA 01923, Tel: (978) 646-2600; http:/ 92 (2018)3
