1、Designation: E 438 92 (Reapproved 2006)Standard Specification forGlasses in Laboratory Apparatus1This standard is issued under the fixed designation E 438; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) 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. Scope1.1 This specification covers the glasses commonly used
3、 tomanufacture laboratory glass apparatus.2. Referenced Documents2.1 ASTM Standards:2C 225 Test Methods for Resistance of Glass Containers toChemical AttackC 338 Test Method for Softening Point of GlassC 598 Test Method for Annealing Point and Strain Point ofGlass by Beam BendingC 729 Test Method fo
4、r Density of Glass by the Sink-FloatComparatorE 228 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 alumino-borosilicate gla
5、ss.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 shown.4.2 Suitable
6、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 shall be as pre-scribe
7、d 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 responsibility of Subcommittee
8、E41.01 onApparatus.Current edition approved Nov. 1, 2006. Published December 2006. Originallyapproved in 1971. Last previous edition approved in 2001 as E 438 92 (2001)e1.2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Ann
9、ual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.TABLE 1 Chemical Requirements of Type I GlassesType I, Class A,weight %Type I, Class B,weight %Major constituents, approximate:SiO281 73B2O313 10Al2O327BaO see below 02CaO see below 1Na2O46K
10、2O 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 glassbecause certain limited applications require a level under 0.1 %.TAB
11、LE 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 1.01Copyright ASTM International, 100 Barr
12、Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.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
13、 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, either reapproved or withdrawn. Your comments
14、 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 attend. If you feel that your comments have not
15、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 copie
16、s) 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).TABLE 3 Physical RequirementsNOTE 1Values in parentheses are the permissible ranges of nominal values and
17、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 300C, cm/cmC 3 107(3233) (4856) (9093) E 22861.5 62 62Annealing point, C 560 574 (520540) C 598610 610 610Soft
18、ening point, C (815820) (783799) (700720) C 338610 610 610Density, annealed, g/cm3(2.232.24) (2.332.36) (2.472.53) C 729A60.02 60.02 60.02Chemical durability, titration equivalent of: 0.02N H2SO4/10 g of glass,max, ml1.0 1.0 9.5 C 225 (Method P-W)ASee Day, R. K., Glass Research Methods, Industrial Publications, Inc., Chicago, IL, 1953, pp. 98100.E 438 92 (2006)2
