ASTM_E_1044_-_96_2011.pdf

Designation:E104496(Reapproved 2011)Standard Specification forGlass Serological Pipets(General Purpose and Kahn)1This standard is issued under the fixed designation E1044;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 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 glass serological pipets,usedin measuring volumes of liquids.2.Referenced 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 Volumetric 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 of ReusableLaboratory Glassware3.Classification3.1 Style and CapacityPipets covered by this specificationshall be of the following styles and capacities:3.1.1 Style IGeneral purpose top end.3.1.2 Style IICotton plugging top end.3.1.3 Style IIICotton plugging top end,large tip opening.3.1.4 Capacities(mL)0.1;0.1(Kahn);0.2;0.2(Kahn);0.25(Kahn);0.5;0.60(Kahn);1.0;2.0;5.0;10.0;and 25.0.4.General Requirements4.1 Borosilicate GlassBorosilicate glass for pipets shallconform to the glass requirements of Type 1,Class A or B ofSpecification E438.4.2 CalibrationPipets shall be calibrated in accordancewith Practice E542 to deliver(TD)the intended capacity ofdistilled water at 20C when the last drop is blown out,exceptthe 0.25 mL Kahn pipet;this Kahn pipet shall have a clearungraduated space of not less than 63 mm between thelowermost graduation mark and the tip of the pipet.The pipetshall be filled about 10 mm above the capacity line.Removeany water on the outside of the tip by a downward wipe withfilter paper.Next,place the tip in contact with the wetted wallof a beaker and slowly lower the meniscus to the capacity line.Do not remove any water remaining on the tip at this time.Delivery of the contents into a receiving vessel is made withthe tip in contact with the wall of the vessel.When the waterhas ceased to flow,the water remaining in the tip is then blownout with one firm puff with the tip in contact with the wall ofthe vessel,if possible.No after-drainage period is allowed.Capacity tolerances shall be within the limits given in Table 1.4.3 AnnealingThe maximum residual thermal stress shallbe such as to conform to Specification E671,except thattempered tips or tempered tops,or both,may be supplied at theoption of the manufacturer.The tempered tip,when examinedin index oil that matches the refractive index of the glass beingused,shall have a temper between 75 and 220 nm.5.Design5.1 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.5.2 Delivery TipsDelivery tips shall be made with agradual taper of 15 to 30 mm for capacities up to 5 mLinclusive,and 20 to 35 mm for 10 and 25 mL capacity pipets.The end of the tip shall be perpendicular to the longitudinalaxis of the pipet.Sudden constriction at the orifice shall not beacceptable.The outside edge of the tip shall be bevelledslightly at the end,and the bevel shall be ground or firepol-ished.5.3 Zero Graduation Line PositionThe distance from thetop end to the top graduation of all pipets(except for 0.5 mL1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved Dec.1,2011.Published December 2011.Originallyapproved in 1985.Last previous edition approved in 2006 as E1044 96(2006).DOI:10.1520/E1044-96R11.2For 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 Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 and Kahn pipets)shall be not less than 100 mm nor more than150 mm from the zero graduation line;for 0.5 mL and Kahnpipets this distance shall be not less than 90 mm nor more than150 mm.5.4 Dimensions and Outflow TimesThe limiting dimen-sions and outflow times shall be as shown in Table 1.Outflowtimes shall be determined on unplugged pipets using distilledwater at 25 6 5C and by means of a stopwatch.Outflow timeshall be determined by the unrestricted outflow of the waterfrom the zero mark until the water has ceased to flow.5.5 MarkingsAll markings shal