1、Designation: E 934 94 (Reapproved 2004)Standard Specification forSerological Pipet, Disposable Plastic1This standard is issued under the fixed designation E 934; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revi
2、sion. 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 disposable plastic
3、serologicalpipets, calibrated “to deliver” when measuring volumes ofliquids.1.1.1 Any institution or individual who reuses a disposablepipet must bear full responsibility for its safety and effective-ness.2. Referenced Documents2.1 ASTM Standards:2D 703 Specification for Polystyrene Molding and Extr
4、usionMaterials3E 542 Practice for Calibration of Laboratory VolumetricApparatusE 920 Specification for Commercially Packaged LaboratoryApparatusE 921 Specification for Export Packaged Laboratory Appa-ratusE 1133 Practice for Performance Testing of Packaged Labo-ratory Apparatus for United States Gov
5、ernment Procure-ments3. Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 accuracythe expected distribution of mean volumesaround the stated volume.3.1.2 coeffcient of variationthe expected distribution ofindividual volumes around the mean volume.3.1.3 disposable pipetsuch pipets w
6、ill only be expected toprovide their specified performance during their original use oroperation.4. Material and Manufacturer4.1 The pipets made to this specification shall be fabricatedfrom crystal grade, uncolored polystyrene, or regrind of same,in accordance with Specification D 703.5. Design5.1
7、Shape0.5, 1.0, and 2.0-cm3pipets shall be straight andof one-piece construction. Any cross section of a pipet taken ina plane perpendicular to the longitudinal axis shall be circular.5.1.1 Pipets of 5.0, 10.0, 25.0, and 50.0 cm3shall be straightand may consist of one, two, or three components, the e
8、xtrudedpipet barrel, the pulled or injection molded tip, and the plain,pulled, or injection molded top end. Any cross section of apipet taken in a plane perpendicular to the longitudinal axisshall be circular.5.2 Delivery TipsDelivery tips shall be made with agradual taper of 10 to 40 mm. The tip en
9、d shall be reasonablyperpendicular to the longitudinal axis of the pipet, and shall befree of internal flash.5.3 Top EndThe 5, 10, 25.0, and 50.0-cm3sizes shall havea top end with an inside diameter of 2 to 6.5 mm for aminimum distance of 20 mm from the open end, and shall havean overall length of 2
10、4 to 28 mm. On all sizes, the top end shallbe suitable for plugging with filtering material. The top may beflat or chamfered and must be without sharp outer edges. Alltop ends shall be reasonably perpendicular to the longitudinalaxis of the pipet. The O.D. of top end should range from 7 to9 mm.5.4 D
11、imensions and Outflow TimesThe limiting dimen-sions and outflow times shall be as shown in Table 1. Outflowtimes shall be determined by means of a stopwatch onunplugged pipets when using distilled water at 25 6 5C.6. Markings6.1 Graduation MarkingsGraduation lines shall be be-tween 0.2 mm and 0.5 mm
12、 in width, and in a plane perpen-dicular to the longitudinal axis of the pipet parallel to eachother. A main graduation line shall extend at least35 of the wayaround the pipet. The values of all main graduation lines shallbe in Arabic numbers directly above the lines referenced.Intermediate graduati
13、on lines shall extend at least15 of the way1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved May 1, 2004. Published May 2004. Originallyapproved in 1983. Last previou
14、s edition approved in 1998 as E 934 94 (1998).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.3Withdrawn.1Cop
15、yright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.around the pipet, and least graduation lines shall extend at least18 of the way around the pipet. The zero graduation line shallbe at least 90 mm below the top of the pipet on all sides.6.2
16、 Identification MarkingsEach pipet shall be markedwith the manufacturers or vendors name or trademark, itscapacity and subdivision, the symbols “TD” (“to deliver”) and“20C”, and either a wide band or two narrow bands on the topend to signify that the last drop must be blown out to achievefull delive
17、ry.7. Capacity7.1 The pipet capacity, expressed as cm3(or mL), and theexpected deviation from the stated capacity, shall be stated onthe product package or published data. The expected deviationfrom stated capacity is expressed as accuracy and coefficient ofvariation. Pipets shall be calibrated for
18、delivery at 20C.7.1.1 The accuracy shall be determined as specified in 7.2and shall be within the limits given in Table 2.7.1.2 The coefficient of variation shall be determined asspecified in 7.2 and shall be within the limits given in Table 2.7.2 Determination of Accuracy and Coeffcient ofVariation
19、A minimum number of 30 pipets in accordancewith Practice E 542, taken at random, shall be tested gravi-metrically, using distilled water. Distilled water at 20 6 1C isdrawn into the pipet and the volume adjusted as in the case ofnormal use. This is discharged into a tared weighing bottle andthe mass
20、, m, is determined using a balance capable of weighingto 60.0001 g. The volume, vx, is computed from the relation:vx5m0.998(1)7.2.1 Accuracy (A)A =(xv1)/v13 100, in percent,x = mean of sample measurements, andv1= stated capacity or stated volume of pipet.7.2.2 Coeffcient of Variation (cv)cv = 100S/
21、x, in percentS = standard deviation5(x 2 x!2n 2 1x = individual sample measurements,x = mean of sample measurements, andn = number of pipets measured.7.2.3 The use of volumetric standards developed from andtraceable to gravimetric standards is permissible if said volu-metric standards were calibrate
22、d using weighings and correc-tions as recommended in Practice E 542.8. Workmanship, Finish, and Appearance8.1 Pipets shall be free from defects that may impair theirserviceability, such as foreign matter or chips that affect thebore.9. Packaging9.1 For packaging, select from Specifications E 920, E
23、921,or Practice E 1157.10. Keywords10.1 disposable; pipet; plastic; serologicalTABLE 1 Dimensions and Outflow TimesCapacity, cm3Least Value Graduation cm3(mL)Outside DiameterGraduated Portion, mmOutflow, sWall Thickness,min, mmMain No. Graduation 0 to min max0.5 0.01 0.1 0.4 4.5 to 4.8 0.5 3.0 0.81.
24、0 0.01 0.1 0.9 4.5 to 4.8 0.5 3.0 0.81.0 0.10 0.1 0.9 4.5 to 4.8 0.5 3.0 0.82.0 0.01 0.1 1.8 5.5 to 6.7 0.5 4.0 0.92.0 0.10 0.2 1.8 5.5 to 6.7 0.5 4.0 0.95.0 0.10 1 4.0 7.6 to 8.4 0.5 7.0 0.910.0 0.10 1 9.0 9.5 to 11.7 0.5 8.0 0.925.0 0.20 or 0.25 1 or 2 23.0 13.0 to 15.0 1.0 10.0 0.750.0 0.25 1 or
25、2 47.0 17.0 to 19.0 2.0 12.0 0.8TABLE 2 Accuracy and Coefficient of Variation of StatedCapacityCapacity cm3Accuracy + %ACoefficient of VariationEqual to or less than1.5 %0.5 3 1.51.0 3 1.52.0 3 1.55.0 3 1.510.0 3 1.525.0 3 1.550.0 3 1.5AAccuracy and coefficient of variation are expressed as a percen
26、tage of thestated capacity.E 934 94 (2004)2ASTM 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 of any such patent rights, and
27、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 are invited either for revision
28、 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 received a fair hearing you shou
29、ldmake 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 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).E 934 94 (2004)3
