1、Designation:E129302(Reapproved 2012)Standard Specification forGlass Measuring Pipets1This standard is issued under the fixed designation E1293;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in pare
2、ntheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification covers requirements for glass measur-ing pipets of precision and general purpose grades,used inmeasuring volumes of liquids.2.Referenc
3、ed Documents2.1 ASTM Standards:2E438 Specification for Glasses in Laboratory ApparatusE542 Practice for Calibration of Laboratory VolumetricApparatusE671 Specification for Maximum Permissible Thermal Re-sidual Stress in Annealed Glass Laboratory ApparatusE694 Specification for Laboratory Glass Volum
4、etric Appa-ratusE920 Specification for Commercially Packaged LaboratoryApparatusE921 Specification for Export Packaged Laboratory Appa-ratusE1133 Practice for Performance Testing of Packaged Labo-ratory Apparatus for United States Government Procure-mentsE1157 Specification for Sampling and Testing
5、of ReusableLaboratory GlasswareE1273 Specification for Color Coding of Reusable Labora-tory Pipets3.Classification3.1 Style,Class and CapacityPipets covered by this speci-fication shall be of the following styles,classes,and capacities:3.1.1 Style 1Standard taper tip.3.1.1.1 Class AEach pipet of pre
6、cision grade shall bemarked with the letter“A”to signify compliance with appli-cable construction and accuracy requirements in Table 1.Eachpipet may be marked with a permanent serial number at theoption of the manufacturer.3.1.1.2 Class BGeneral purpose pipets are of the samebasic design as Class A
7、pipets.Volumetric tolerances for ClassB pipets shall be within twice the specified range allowed forClass A pipets.These pipets need not be marked with theirclass designation or serial number.See Table 1 for tolerancesand dimensional requirements.3.1.2 Style 2Long taper tip(Class B only).3.1.3 Capac
8、ities,(mL)0.1,0.2,0.5,1,2,5,10,25,and 50.4.Design4.1 ShapeThe pipets shall be straight and of one-piececonstruction.Any cross section of a pipet taken in a planeperpendicular to the longitudinal axis shall be circular.4.2 Delivery TipsDelivery tips of Style 1 pipets shall bemade with a gradual taper
9、 of 15 to 30 mm for capacities up to5 mL inclusive,and 20 to 40 mm for 10 to 50 mL capacitypipets.Style 2 pipets shall have a taper at a distance of 50 to 65mm from the tip end.The end of the tip shall be perpendicularto the longitudinal axis of the pipet.A sudden constriction atthe orifice shall no
10、t be acceptable.The outside edge of the tipshall be beveled slightly at the end,and the bevel shall beground or firepolished.4.3 Zero Graduation Line Position The distance from thetop end to the top graduation of all pipets(except for 0.5 mLpipets)shall be not less than 90 mm;for 0.5 mL pipets thisd
11、istance shall be not less than 80 mm.4.4 Dimensions and Outflow TimesThe limiting dimen-sions and outflow times are shown in Table 1.Outflow timesshall be determined on unplugged pipets using distilled waterat 256 5C and by means of a stopwatch.Outflow time shallbe determined by the unrestricted out
12、flow of the water from thezero mark to base mark and until the water has ceased to flow.4.5 MarkingsAll markings shall be permanent and leg-ible.4.5.1 Graduation MarkingsGraduation lines shall not ex-ceed 0.4 mm in thickness and shall be in a plane perpendicularto the vertical axis of the pipet.The
13、lines and other markingsshall be applied by one of the following methods:etched andfilled with a permanent pigment;etched through a verticalcolored stripe fused into the glass;by application of a stain1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is t
14、he direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved Nov.1,2012.Published November 2012.Originallyapproved in 1989.Last previous edition approved in 2007 as E1293 02(2007).DOI:10.1520/E1293-02R12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcon
15、tact 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 States1 fired into the glass without
16、 etching;or by application of anenamel fired onto the glass without etching.4.5.1.1 Style 1,Class A pipetsShall comply with thelengths of lines,numbering and Graduation Pattern 1 specifiedin Specification E694.4.5.1.2 Style 1,Class B and Style 2 pipetsMain gradua-tions shall extend a minimum of34of the way around the pipet;intermediate graduations shall extend a minimum of15of theway around the pipet,and the least graduation markings shallextend a minimum of17of the way around the pipet.The valu
