1、Designation: E 788 97 (Reapproved 2008)Standard Specification forPipet, Blood Diluting1This standard is issued under the fixed designation E 788; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A number i
2、n parentheses indicates the year of last reapproval. Asuperscript epsilon () 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 requirements for glass reusableblood
3、 diluting pipets that are used for performing red and whitecell corpuscle determinations.2. Referenced Documents2.1 ASTM Standards:2E 694 Specification for Laboratory Glass Volumetric Appa-ratusE 920 Specification for Commercially Packaged LaboratoryApparatusE 921 Specification for Export Packaged L
4、aboratory Appa-ratusE 1133 Practice for Performance Testing of Packaged Labo-ratory Apparatus for United States Government Procure-mentsE 1157 Specification for Sampling and Testing of ReusableLaboratory Glassware3. Classification3.1 This specification covers two different pipet designs andpermissib
5、le alternatives.3.1.1 Red and white cell blood diluting pipets (see Fig. 1).3.1.2 Permissible alternative designs (see Fig. 2).4. Materials4.1 The pipets shall be made of common spirit bore whiteback tubing or clear glass with a white stripe applied to theouter surface of the tubing.4.2 The beads sh
6、all be made of glass or ceramic composi-tion and shall be of red, clear, or white coloring.5. Dimensions and Permissible Variations5.1 DesignThe red and white cell blood dilution pipetsshall consist of a small uniform bore glass tube which shallhave a bulb of proper size near the proximal end (see F
7、ig. 1).As an alternative, the pipets may be constructed of three piecesof glass that are fused together to form a one-piece pipet (seeFig. 2). The bulb shall contain a nonspherical glass or ceramicbead sufficiently large enough to prevent its being impacted inthe constriction portion of the bulb. Th
8、e cross section of thepipet at any point shall be circular. The distal end of the whitecell pipet shall be pulled to a point and then ground andpolished to a tapered tip. The distal end of the red cell pipetshall be ground and polished to a tapered tip. The insidediameter (ID) of the pipet bore at t
9、he tip end of the white cellpipet shall be 0.2 to 0.5 mm. The external diameter of theground and polished tip shall not exceed 2.0 mm. The overalllength of both pipets shall be 104 to 121 mm. The proximal endmay be of funnel design, with an exterior taper, or ground andpolished with a taper of suffi
10、cient angle to permit application ofa rubber suction tube or other suction device (see Fig. 2).5.2 CapacityThe capacity of the red cell pipet bulb shallbe 0.8 to 1.2 cm3and the capacity of the white cell bulb shall be0.2 to 0.4 cm3. The capacity of the red cell pipet stem (bulb todistal end) shall b
11、e 0.008 to 0.012 cm3and the capacity of thewhite cell pipet stem shall be 0.02 to 0.04 cm3.5.3 Capacity Markings:5.3.1 Pipet Bulb MarkingsThe red and white cell pipetbulb capacity shall be confined to and indicated by calibrationlines on the pipet. These lines shall be located on both sides ofthe bu
12、lb and shall be within 2 mm to 6 mm above the bulb(proximal end) and within 3 mm to 6 mm below the bulb (distalend). The exact manner for measuring these line placements isspecified in Fig. 1.5.3.2 Pipet Stem MarkingsThe graduation lines on thestem of the red and white cell pipets shall be equally d
13、ividedinto two or ten divisions. If there are two divisions, the twocalibration lines on the stem will be numbered 0.5 and 1. Ifthere are ten divisions, the ten calibration lines will benumbered 0.5 on the fifth line and 1 on the tenth linerespectively. The top line (above bulb at the proximal end)s
14、hall be numbered 101 on the red cell pipet and 11 on the whitecell pipet, representing stem and bulb volume collectively. Atthe option of the manufacturer, pipet stems may be graduatedwith split lines or partial length lines (see Fig. 2).1This specification is under the jurisdiction of ASTM Committe
15、e E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee E41.01 onApparatus.Current edition approved Nov. 1, 2008. Published January 2008. Originallyapproved in 1981. Last previous edition approved in 2003 as E 788 97(2003).2For referenced ASTM standards, visit the ASTM website,
16、 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.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.5
17、.4 Graduation LinesAll graduation lines on the red andwhite cell pipets shall be at right angles to the pipet axis andparallel to each other. The thickness of the graduation linesshall not exceed 0.4 mm.5.5 AccuracyThe red and white cell pipet bulb volumeshall be a volumetric ratio to the stem volum
18、e. The red cellpipet bulb to stem ratio shall be 100:1 and the white cell pipetbulb to stem ratio shall be 10:1 when tested in accordance with6.1 and 6.2.5.6 Workmanship:5.6.1 The pipets shall be free of defects that detract fromtheir appearance or impair their serviceability.5.6.2 Construction shal
19、l be such that the mechanicalstrength is provided to withstand the rigors of normal use. Thepipets shall be free of strain when tested in accordance with6.4.5.7 IdentificationEach pipet shall have the name or reg-istered trademark of the manufacturer. These markings are tobe located on the stem of t
20、he pipet directly opposite thegraduation lines. The manufacturer has the option to state thepipet volumetric tolerances on the pipet. These tolerances maybe located on the stem or the proximal end of the pipet.5.7.1 The white cell pipet shall have a clear or white glassor ceramic bead sealed within
21、the bulb to identify it readily asa white cell pipet.5.7.2 The red cell pipet shall have a red glass or ceramicbead sealed within the bulb to identify it readily as a red cellpipet.5.8 PigmentationAll markings shall be permanently fusedin or on the pipet. The markings shall be dark amber or blackin
22、color. When tested in accordance with 6.3, the pigmentationshall not discolor the solution. The appearance of the markings,when viewed by the eye under normal room lighting, shall bethe same after testing as before testing.6. Testing6.1 AccuracyAccuracy for these pipets shall be 65 % forred cell pip
23、ets and 63.5 % for white cell pipets. If V representsthe volume between the calibration lines immediately aboveand below the bulb, V1represents the volume of the capillarystem between the pipet tip and the calibration line numbered 1,and V2represents the volume of the capillary stem between thetip a
24、nd the calibration line numbered 0.5, the volumetrictolerances shall be as stated in Specification E 694 and ex-pressed as follows:FIG. 1 Pipet DimensionsE 788 97 (2008)26.1.1 Red Cell PipetsNominal ratio 100:1V/V1shall not be less than 95 or more than 105V/V2shall not be less than 190 or more than
25、2106.1.2 White Cell PipetsNominal ratio 10:1V/V1shall not be less than 9.65 or more than 10.35V/V2shall not be less than 19.30 or more than 20.706.2 Accuracy DeterminationV2, V1, and V shall be deter-mined by use of distilled water and a weighing device havinga weight sensitivity no less than 0.001
26、mg.6.2.1 The weight of a dry red or white cell pipet shall betaken first and recorded. This indication shall be subtractedfrom the weight indications of the red or white cell pipet filledwith distilled water to the lines numbered 0.5, 1, 101, or 11respectively. The weight of the water at temperature
27、 T,istobeconverted to volume at 20C. The net weight indicationsrepresent V2, V1, and V factors given in 6.1.1 and 6.1.2.6.3 Pigmentation TestFreshly prepare a chromic acidcleaning solution by combining 200 g of sodium dichromate(Na2Cr2O72H2O), 1000 mL of water, and 1500 mL ofsulfuric acid (H2SO4, AC
28、S Reagent 95 to 98 %). Immerse thepipets in the chromic acid solution. Let stand at room tempera-ture (20 to 25C) for 15 min. Remove the pipets from thesolution and thoroughly rinse in distilled water. Dry the pipetsby rubbing vigorously, 5 to 10 strokes, with a laboratory clothor tissue. The appear
29、ance of the markings should be the sameas before the test, when judged by the eye under normal roomlighting.6.4 Strain-Free TestThe pipets shall be free from strainwhen viewed under a polariscope.6.5 For additional sampling and testing data, see Specifica-tion E 1157.7. Packaging7.1 For packaging, s
30、elect from either Specification E 920,Specification E 921, or Practice E 1133.8. Keywords8.1 blood; glass; pipetsFIG. 2 Permissible AlternativesE 788 97 (2008)3ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this stan
31、dard. Users of this standard are expressly advised that determination of the validity 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 revie
32、wed every five years andif not revised, either reapproved or withdrawn. Your comments 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 theresponsibl
33、e technical committee, which you may attend. If you feel that your comments have not 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 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 788 97 (2008)4
