1、Designation:E12494(Reapproved 2010)Standard Specification forWeighing and Drying Apparatus for Microchemical Analysis1This standard is issued under the fixed designation E124;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year o
2、f 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 specification covers apparatus used for weighingand drying operations in microchemical laboratory practice.1.2 The v
3、alues stated in inch-pound units are to be regardedas the standard.The metric equivalents may be approximate.NOTE1This specification was originally developed by the Committeeon MicrochemicalApparatus,Division ofAnalytical Chemistry,AmericanChemical Society.22.Referenced Documents2.1 ASTM Standards:3
4、E671 Specification for Maximum Permissible Thermal Re-sidual Stress in Annealed Glass Laboratory ApparatusE920 Specification for Commercially Packaged LaboratoryApparatusE921 Specification for Export Packaged Laboratory Appa-ratusE1133 Practice for Performance Testing of Packaged Labo-ratory Apparat
5、us for United States Government Procure-mentsE1157 Specification for Sampling and Testing of ReusableLaboratory Glassware3.Combustion Boats3.1 Combustion boats of three sizes shall conform to therequirements in Table 1 and Fig.1,Fig.2,and Fig.3.Theseboats shall be made of platinum-rhodium alloy cont
6、aining3.5%rhodium.4.Weighing Bottles4.1 Weighing bottles of seven capacities shall conform tothe requirements in Table 2 and Figs.4-9,inclusive.5.Weighing Cup5.1 The weighing cup shall conform to the requirementsshown in Fig.11,and shall be made of platinum-rhodium alloycontaining 3.5%rhodium.The cu
7、p is designed to be used as asample container to fit into the weighing bottle shown in Fig.5,and is useful for weighing hygroscopic materials.6.Weighing Tubes6.1 Weighing tubes of three types shall conform to therequirements shown in Fig.12,Fig.13,and Fig.14.Thesetubes should preferably be made of s
8、oda-lime glass.7.Spatulas7.1 Spatulas of four types,and preferably made of stainlesssteel,shall conform to the following requirements:7.1.1 Type A(Fig.15)This spatula is generally useful.Thetop can be used for crushing crystals and the bent blade forscraping containers.7.1.2 Type B(Fig.16)This spatu
9、la has a flat bent portionat one end and a V-shaped scoop at the other end.It isparticularly useful for weighing samples.7.1.3 Type C(Fig.17)This spatula is suitable for the largersamples commonly encountered in semimicro and preparativework.It has a U-shaped scoop at one end and a V-shaped scoopat
10、the other end.The spatula can be used to add shot or beadsto tare flasks and for measuring and introducing solid reagentinto combustion tubes.7.1.4 Type D(Fig.18)This spatula is useful in manymicrochemical applications.8.Forceps8.1 Forceps of two types,made of nickel-plated steel,shallconform to the
11、 following requirements:8.1.1 Forceps with Platinum5%Ruthenium Tips(Fig.19)The pin serves as a stop to prevent the forceps from beingdepressed to such an extent that the tips can open,allowing theheld object to drop.When pressed together,the tips makecontact for a distance of14to12in.(6.4 to 12.7 mm
12、).NOTE2Depending upon the intended use,other materials may be1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved July 1,2010.Published July 2010.Originally approvedin 1
13、956.Last previous edition approved in 2005 as E124 94(2005).DOI:10.1520/E0124-94R10.2See the“1949 Report on Recommended Specifications for MicrochemicalApparatus,Carbon-Hydrogen,Dumas Nitrogen,Sulfur and Halogen,”AnalyticalChemistry,Vol 21,December 1949,p.1555;and the“1953 Report on Recom-mended Spe
14、cifications for Microchemical Apparatus,Weighing and Drying,”Analytical Chemistry,Vol 26,July 1954,p.1186.3For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards D
15、ocument Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 substituted for the platinum alloy.Thec construction and over-all dimen-sions should be identical with those shown in Fig.19.8.1.2 Forceps with Conica
16、l Tapered Holders(Fig.20)These forceps shall be made of spring steel.They are useful forhandling weighing tubes,absorption tubes,filter tubes,etc.9.Tare Flasks9.1 Tare flasks of three types,made of soda-lime glass,shallconform to the requirements shown in Fig.21,Fig.22,and Fig.23.The serial numbers shall be etched on the flasks.10.Metal Cooling Block10.1 The metal cooling block shall conform to the require-ments shown in Fig.24,and shall be made of a metal or alloywith a high heat conductivity.T
