1、BRITISH STANDARD BS6706:1986 Specification for Disposable glass serological pipettes UDC 542.3:531.732:666.172.7BS6706:1986 This BritishStandard, having been prepared under the directionof the Laboratory Apparatus Standards Committee,was published underthe authority of the BoardofBSI and comes intoe
2、ffecton 31October1986 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference LBC/27 Draft for comment82/52908 DC ISBN 0 580 15161 1 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted by the Laboratory Appar
3、atus Standards Committee (LBC/-) to Technical Committee LBC/27 upon which the following bodies were represented: Association of Clinical Biochemists British Laboratory Ware Association British Lampblown Scientific Glassware Manufacturers Association Ltd Department of Health and Social Security Depar
4、tment of Trade and Industry (Laboratory of the Government Chemist) Department of Trade and Industry (National Weights and Measures Laboratory) Glass Manufacturers Federation Institute of Medical Laboratory Sciences Medical Sterile Products Association Ministry of Defence Society of Chemical Industry
5、 South Western Regional Health Authority Amendments issued since publication Amd. No. Date of issue CommentsBS6706:1986 BSI 12-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Classification 1 4 Basis of adjustment 1 5 Construction 1 6 Delivery t
6、ime 2 7 Volumetric performance 2 8 Graduation and figuring 2 9 Inscriptions 3 10 Labelling 3 11 Colour coding 3 Appendix A Determination of delivered capacity 4 Appendix B Determination of accuracy and repeatability 4 Table 1 Capacity, subdivision, dimensions and delivery time 2 Publications referre
7、d to Inside back coverBS6706:1986 ii BSI 12-1999 Foreword This BritishStandard has been prepared under the direction of the Laboratory Apparatus Standards Committee. This BritishStandard is related to ISO7713:1985 published by the International Organization for Standardization (ISO), differing from
8、its technical requirements in the following respects: a) the external diameter of the0.5mL and1.0mL pipettes is4.0mm to4.75mm instead of4.25mm to4.75mm; b) the external diameter of the5mL pipette is6.5mm to8.25mm instead of7.0mm to8.25mm; c) the minimum wall thickness of the0.5mL,1mL,2mL and5mL pipe
9、ttes is0.5mm instead of0.6mm; d) the blow-out type may, in addition or as an alternative to being inscribed with a white band, be inscribed with the wording “Blow-out”. Purchasers ordering to this standard are advised to specify in their purchasing contract that the supplier operates a quality syste
10、m in compliance with BS5750-3 to ensure that products claimed to comply with BS6706 consistently achieve the required level of quality. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application.
11、 Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may h
12、ave had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS6706:1986 BSI 12-1999 1 1 Scope This BritishStandard specifies the dimensions and construction of a range of disposable serological pipettes suitable for general laboratory purposes. A method f
13、or determining volumetric performance of the pipettes is included. Two types (flow-out and blow-out) are specified. NOTE 1The requirements specified in this standard are in accordance with the principles described in ISO8417 and the pipettes specified in this standard are related to those specified
14、in ISO7713 (seeforeword). ISO8417 is in preparation but it is expected to be published as a dual-numbered BritishStandard. NOTE 2The titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this BritishStandard the following defin
15、itions apply. 2.1 disposable serological pipette a serological pipette intended to be used once only and then discarded NOTESuch pipettes will only be expected to provide their specified performance during the original operation. 2.2 standard reference temperature the temperature at which the serolo
16、gical pipette is intended to deliver its nominal volume (nominal capacity) 2.3 delivered capacity of flow-out pipettes the volume, in millilitres, of water corresponding to any graduation line, delivered by the pipette, at the standard reference temperature, when emptied from the zero line to that g
17、raduation line; the outflow is unrestricted until making the final setting of the meniscus on the graduation line and no period is allowed for drainage of liquid adhering to the wall before making the final setting 2.4 delivered capacity of blow-out pipettes the volume, in millilitres, of water corr
18、esponding to any graduation line, delivered by the pipette, at the standard reference temperature, when emptied from the graduation line to the jet; the outflow is unrestricted until the meniscus has come to rest in the jet but delivery is completed by expelling the last drop by blowing NOTEIt shoul
19、d be borne in mind that the delivered volume is the complement of that indicated, e.g.if the indication on a10mL pipette is4mL, the delivered volume is6mL. 2.5 delivery time the time taken for the descent of the water meniscus, at the standard reference temperature, from the zero graduation line to
20、the point at which it appears to come to rest in the jet 2.6 accuracy the closeness of agreement between the nominal volume and the mean volume, obtained by applying the test procedure specified in clause7. It is quantified by the inaccuracy of the mean 2.7 repeatability the closeness of agreement b
21、etween the individual volumes obtained by applying the test procedure specified in clause7. It is quantified by imprecision NOTEThe definitions for accuracy and repeatability apply only in cases where the distributions are gaussian. 3 Classification The disposable serological pipettes shall be of th
22、e types described in a) or b) as follows: a) flow-out type, in which the delivered capacity is obtained without expelling the final drop by blowing; b) blow-out type, in which the delivered capacity is obtained by expelling the final drop by blowing. 4 Basis of adjustment 4.1 Unit of volume The unit
23、 of volume shall be either the millilitre or the cubic centimetre. NOTEThe millilitre is commonly used as a name for the cubic centimetre, in accordance with the International System of Units (SI). 4.2 Standard reference temperature The standard reference temperature shall be20 C, except when the se
24、rological pipette is required for use in a country that has adopted a standard reference temperature of27 C, in which case27 C shall be the standard reference temperature. NOTE27 C is the alternative standard reference temperature recommended in BS5898 for tropical use. 5 Construction 5.1 Material D
25、isposable serological pipettes shall be manufactured from soda-lime-silica, neutral or borosilicate glass complying with the requirements of class3 or better of BS3473-2. NOTEThe pipettes should be as free as possible from visible defects and free from any internal stress that would impair the perfo
26、rmance of the pipette.BS6706:1986 2 BSI 12-1999 5.2 Dimensions The dimensions shall comply with the requirements shown in Table 1. 5.3 Straightness The pipettes shall be straight. 5.4 Ovality At any cross section of a pipette, taken in a plane perpendicular to the longitudinal axis, the maximum and
27、minimum external diameters shall not differ by more than2%. 5.5 Delivery jet The lower end of the pipette shall terminate in a delivery jet having a smooth and gradual taper without any sudden constriction at the orifice which could give rise to turbulent outflow. The length of the tapered portion s
28、hall be: a) 10mm to25mm for capacities up to2mL inclusive; b) 15mm to30mm for the5mL and10mL capacities. The jet end shall be either fire-polished, without run-in, or clean cut, without appreciable toe nail or chip that affects the bore. 5.6 Suction end All suction ends shall be fire-polished. NOTEA
29、ll suction ends should be reasonably perpendicular to the longitudinal axis of the pipette. The suction end of the10mL pipette shall be either of unreduced diameter or of reduced external diameter of7mm to9mm and an overall length from15mm to25mm. The5mL pipettes and the10mL pipettes of unreduced di
30、ameter shall have a constriction located between15mm and25mm from the top. The suction end shall be dimensionally suitable for plugging with filtering material. 5.7 Workmanship The pipettes shall be free from foreign matter, loose or embedded lint, chips that affect the bore and stains when viewed u
31、nder normal room lighting. 6 Delivery time The delivery time, when determined with the pipette unplugged and using water complying with BS3978, shall be within the limits specified in Table 1. 7 Volumetric performance The volumetric performance shall be determined for either a single pipette or a mi
32、nimum of30pipettes. The delivered capacity shall be determined in accordance with BS6696 supplemented by Appendix A. The volumetric accuracy and repeatability shall be determined in accordance with Appendix B. The accuracy and repeatability of the delivered capacity shall be within the limits stated
33、 by the manufacturer. 8 Graduation and figuring The pipettes shall be graduated in accordance with the graduation pattern III of BS5898:1980, and figured accordingly. NOTEWhen a BritishStandard corresponding to ISO8417 (see note1 to clause1) is published, this clause will be amended to make referenc
34、e to that standard rather than BS5898. Graduation and figuring shall be durable until the pipette has been used. The pipette shall be graduated from zero at the top down to the lowest graduation line according to Table 1. The distance between the top of the pipette and zero line shall be at least90m
35、m. Table 1 Capacity, subdivision, dimensions and delivery time Nominal capacity Smallest scale division Lowest graduation line External diameter a Minimum wall thickness Delivery times Minimum Maximum mL mL mL mm mm s s 0.1 0.2 0.5 1 1 2 5 10 0.01 0.01 0.01 0.01 0.1 0.01 0.1 0.1 0.09 0.18 0.45 0.9 0
36、.9 1.9 4.5 9 3.5to4 3.5to4.5 4.0to4.75 4.0to4.75 4.0to4.75 5to6 6.5to8.25 9.5to11.25 1 1 0.5 0.5 0.5 0.5 0.5 0.6 0.5 0.5 0.5 0.5 0.5 0.5 3 4.5 3 3 3 5 5 5 10 15 a Graduated part.BS6706:1986 BSI 12-1999 3 9 Inscriptions 9.1 The following inscriptions shall be marked on all disposable serological pipe
37、ttes: a) a number indicating the nominal capacity and, adjacent or subjacent to this number, either the symbol “cm 3 ” or the symbol “mL” to indicate the unit of graduation (seenote to4.1); b) the inscription “20 C” or “27 C” to indicate the standard reference temperature (see4.2); c) the letters “E
38、x” to indicate that the pipette has been adjusted to deliver its indicated capacity; d) the makers and/or vendors name or mark. 9.2 The word “Blow-out” and/or a white enamelled (or etched or sand-blasted) band3mm to5mm wide shall additionally be inscribed on all blow-out pipettes. 10 Labelling Each
39、package of serological pipettes shall be clearly labelled with the following information: a) the makers and/or vendors name or mark; b) the product description, e.g.disposable serological pipettes,5mL; c) the volumetric performance in terms of accuracy and repeatability; d) the number of pipettes in
40、 the package; e) the batch number or date of manufacture; f) the number and date of this BritishStandard, i.e.BS6706:1986 1) . 11 Colour coding Colour coding, if used, shall comply with the requirements of BS3996. 1) Marking BS6706:1986 on or in relation to a product is a claim by the manufacturer t
41、hat the product has been manufactured to the requirements of the standard. The accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification should be addressed to the appropriate certification body.BS6706:1986 4 BSI 12-1
42、999 Appendix A Determination of delivered capacity NOTEAppendix A supplements paragraph3 of10.5.1 of BS6696:1986 and describes the method of handing the pipette for the determination of the delivered capacity. Hold the clean pipette, filled with distilled water to a few millimetres above the zero li
43、ne, in a vertical position. Set the falling meniscus to the line. Set the meniscus so that the plane of the upper edge of the graduation line is horizontally tangential to the lowest point of the meniscus, the line of sight being in the same plane. In order that the lowest point of the meniscus may
44、be observed, place a shade of some dark material immediately below and behind the meniscus. NOTEThis renders the profile of the meniscus dark and clearly visible against a light background. Remove any drop adhering to the jet of the pipette by bringing the surface of a glass vessel in contact with t
45、he tip of the jet. Deliver the water into another glass vessel slightly inclined so that the tip of the jet is in contact with the inside of the vessel, but without movement of one against the other throughout the delivery period. In case of delivery of the total capacity (to the jet), leave the out
46、flow also unrestricted. In order to ensure that delivery is complete, observe a waiting time of approximately3s before removing the pipette from the receiving vessel. In the case of blow-out pipettes, after the3s waiting time, expel the last drops by blowing and then remove the pipette from the rece
47、iving vessel. NOTEThe waiting period of3s is specified only for the purpose of definition. In use, it is unnecessary to adhere closely to this period; it is sufficient to be certain that the meniscus has come to rest in the jet before either removing the pipette from contact with the receiving vesse
48、l or blowing out the pipette, as appropriate. Appendix B Determination of accuracy and repeatability B.1 Volumetric capacity deviation (single pipette) The percentage capacity deviation for a single pipette C shall be calculated from the following equation: B.2 Volumetric capacity deviation (number
49、of pipettes) B.2.1 Percentage volumetric error The percentage volumetric error V for a minimum of30 pipettes shall be calculated from the following equation: B.2.2 Percentage coefficient of variation The percentage coefficient of variation A shall be calculated from the following equation: where V 0 is the nominal capacity of the pipette; V 1 is the delivered capacity at the reference temperature. where is the mean of the sample measurements at the reference temperature; V 0 is the nominal capacity of the pipette. where is the mean of the sample measurements at t
