1、Designation: E 287 02Standard Specification forLaboratory Glass Graduated Burets1This standard is issued under the fixed designation E 287; 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 (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers requirements for glass buretsof precision and general-purpose grades suitable for laboratoryuse.1.1.1 Class AEach buret of
3、 precision grade may bemarked with the letter “A” to signify compliance with appli-cable construction and accuracy requirements in Table 1 andTable 2. Each buret may be marked with a permanent serialnumber at the option of the manufacturer.1.1.2 Class BGeneral purpose burets are of the same basicdes
4、ign as Class A burets. However, volumetric tolerances forClass B burets shall be within twice the specified range allowedfor Class A burets. These burets need not be marked with theirclass designation or serial number. See Table 1 and Table 3 fortolerances and dimensional requirements.NOTE 1The Twel
5、fth General (International) Conference on Weightsand Measures redefined the litre as a “special name for the cubicdecimetre,” but agreed to permit continuance of the terms litre, millilitre,and mL, except in association with measurements of the highest precision.For volumetric glassware the differen
6、ce between the old and newmeanings of litre is negligible. Therefore, either mL or cm3may bemarked on ware covered by this standard.1.1.3 Product with a stated capacity not listed in thisstandard may be specified Class A Tolerance when productconforms to the tolerance range of the next smaller volum
7、etricstandard product listed in Table 1.2. Referenced Documents2.1 ASTM Standards:D 664 Test Method for Neutralization Number by Potentio-metric Titration2E 438 Specification for Glasses in Laboratory Apparatus3E 542 Practice for Calibration of Volumetric Ware3E 675 Specification for Interchangeable
8、 Taper-GroundStopcocks and Stoppers3E 694 Specification for Volumetric Ware3E 911 Specification for Glass Stopcocks with Polytetrafluo-roethylene (PTFE) Plugs3E 920 Specification for Commercially Packaged LaboratoryApparatus3E 921 Specification for Export Packaged Laboratory Appa-ratus3E 1133 Practi
9、ce for Performance Testing of Packaged Labo-ratory Apparatus United States Government Procurement3E 1157 Specification for Sampling and Testing ReusableLaboratory Glassware33. General Requirements3.1 CalibrationBurets shall be calibrated to deliver theintended volume at 20C. No after-drainage period
10、 is allowed.Volumetric tolerances shall be within the limits specified inTable 1.4. Design4.1 ShapeThis specification covers 10, 25, 50 and100-mL straight burets with single-bore stopcock; 10, 25, 50and 100-mL straight burets with 3-way stopcock; 100-mLburets with 50-mL bulb (intermediate bulb style
11、); and 10, 25,50 and 100-mL self-zeroing burets.4.1.1 Self-zeroing burets shall have an ungraduated, ta-pered, interior extension that terminates with an overfloworifice. The exterior of the buret shall extend reasonablybeyond the terminal point of the interior overflow orifice. Anexterior outlet tu
12、be positioned below the overflow orifice shallalso be provided for drainage of overflow. End of outlet tubeshall be slightly enlarged and bulbous for attachment to flexibletubing.4.1.2 A cross section of the graduated portion of all buretstyles taken in a plane perpendicular to their longitudinal ax
13、isshall be circular.4.2 Filling TubeBurets may be equipped with a fillingtube as described below.4.2.1 For Class A burets, filling tubes may either be attachedto the underside of a 3-way stopcock or mounted onto thelower ungraduated body of those burets having straight borestopcocks. Filling tubes w
14、hich are mounted onto the body ofClass A burets must utilize a separate stopcock integral with thefilling tube. When a separate stopcock is used, positioning of1This specification is under the jurisdiction of ASTM Committee E41 onLaboratory Apparatus and is the direct responsibility of Subcommittee
15、E41.01 onApparatus.Current edition approved Oct. 10, 2002. Published November 2002. Originallypublished as E 287 65T. Last previous edition E 287 94 (1998).2Annual Book of ASTM Standards, Vol 05.01.3Annual Book of ASTM Standards, Vol 14.04.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box
16、 C700, West Conshohocken, PA 19428-2959, United States.the stopcock must be oriented so that the handle of thestopcock plug is readily accessible when buret is in normalviewing position.4.2.2 Filling tubes attached to 3-way stopcocks shall be inthe form of an elbow, extending downward from the stopc
17、ock.The open end of the filling tube shall extend toward the rearfrom the buret and be slightly enlarged or bulbous for firmlysecuring flexible tubing.4.2.3 Class B burets may have filling tubes affixed in any ofthe methods described for Class A burets or as an alternative beattached to the lower un
18、graduated portion of buret bodywithout an integral stopcock.4.3 Dimensions and TolerancesBurets shall comply withthe essential dimensions and tolerances shown in Table 1,Table 2, and Table 3.4.4 StopcocksAll burets shall have permanently attachedstopcocks. The stopcocks handle shall be located to th
19、e right.Stopcock plugs shall be provided with a retaining device.Stopcock plugs may be either glass or TFE-fluorocarbon.All-glass stopcocks shall conform to size 2 of SpecificationE 675. The TFE-fluorocarbon plugs shall have tapers of 1 mmfor each 5 mm of length and shall conform to the requirements
20、of Specification E 911.4.4.1 In addition, stopcocks that form a seal by having theirTFE-fluorocarbon plug ends butt against a necked-down glassshell may be used, provided thata4mmmaximum insidediameter is used for the necked-down region.4.5 Delivery StemsThe delivery stem shall have a totallength of
21、 70 6 5 mm, except for the 10-mL size which mayhave a stem 100 to 130 mm long (to comply with Test MethodD 664). The stem shall be permanently attached to the buretand shall be made with a gradual taper at the lower end of 20to 30 mm. The end of the tip shall be ground perpendicular tothe longitudin
22、al axis of the tip and beveled, or it may befire-polished instead of grinding. A sudden constriction at theorifice shall not be acceptable.4.6 Delivery TimeThe rate of outflow shall be restrictedby the size of the opening in the tip, and shall be not less thanthe times shown in Table 2 for Class A b
23、urets and Table 3 forClass B burets.4.7 MarkingsAll markings shall be permanent and leg-ible.4.7.1 Calibration LinesCalibration lines shall be sharplydefined and of uniform width (maximum 0.4 mm) in a planeperpendicular to the axis of the buret and parallel to each other.Lines shall be spaced at lea
24、st 1 mm apart, center to center oflines. All main lines shall be numbered. Lines and numbersshall be applied by one of these methods: etched and filled withpermanent pigment, by application of a stain that is fired intothe glass without etching, or by application of an enamel whichis fused on the gl
25、ass without etching.4.7.1.1 Class ALeast calibration lines shall extend aminimum of one half and intermediate lines at least two thirds,respectively, of the way around the outside circumference ofthe buret. If lines are etched, the main (numbered) lines shallextend completely around the circumferenc
26、e of the buret; iflines are of stain or enamel, a gap is permitted in the main linesimmediately to the right of the numbers. The gap shall notexceed 4 mm for 10 and 25-mL burets, and 7 mm for 50 and100-mL burets.4.7.1.2 Class BLeast calibration lines shall extend aminimum of one sixth and intermedia
27、te lines at least onefourth, respectively, of the way around the outside circumfer-ence of the buret. If lines are etched, the main (numbered) linesshall extend completely around the circumference of the buret;if lines are of stain or enamel, the main lines shall extend aminimum of three fourths of
28、the way around the outsidecircumference of the buret.4.7.2 Identification MarkingsEach buret, marked by oneof the methods given in 4.7.1, shall show the manufacturersname or trademark, the word “Delivers” or the equivalentsymbol “TD,” the temperature of calibration, that is, 20C, andthe time for unr
29、estricted delivery of the total nominal volume.The actual delivery time may vary from the marked deliveryTABLE 1 Requirements for BuretsGraduated ScaleCapacity,mLSubdivision,mLClass Aand BClass AScale Length,mm0 to CapacityClass BScale Length,mm0 to CapacityDistance, Topof Buret to “0”Graduation,mmA
30、Class Aand BNumberEach, mLClass AVolumetricTolerance,6mLClass BVolumetricTolerance,6mL10 0.05 350 to 450 250 to 450 30 to 75 0.5 0.02 0.0425 0.1 350 to 450 250 to 450 30 to 75 1 0.03 0.0650 0.1 500 to 600 500 to 600 40 to 100 1 0.05 0.10100 0.2 550 to 650 550 to 650 40 to 100 2 0.10 0.20AStraight bu
31、rets only, not applicable to self-zeroing burets.TABLE 2 Minimum Delivery Time for Class A BuretsUsing WaterLengthGraduated,cmTime of Out-flow NotLess Than, sLengthGraduated,cmTime of Out-flow Not LessThan, s15 30 45 8020 35 50 9025 40 55 10530 50 60 12035 60 65 14040 70 70 160TABLE 3 Minimum Delive
32、ry Time for Class B BuretUsing WaterCapacity, mLTime of Outflow Not LessThan, s10 2525 3050 50100 90E287022time by 6 15 s, provided the actual time is greater than theminimum given in Table 2 or Table 3.5. Sampling and Testing5.1 For sampling and testing, refer to Specification E 1157.6. Packaging6.
33、1 For packaging, select from Specification E 920 or E 921or Practice E 1133.7. Keywords7.1 burets; glass; graduatedASTM 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 ad
34、vised 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 reviewed every five years andif not revised, eithe
35、r 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 theresponsible technical committee, which you may attend.
36、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).E287023
