1、BRITISH STANDARD BS1132:1987 Specification for Automatic pipettes UDC 542.3:531.732BS1132:1987 This British Standard, having been prepared under the directionof the Laboratory Apparatus Standards Committee,was published underthe authorityof the BoardofBSI andcomes intoeffecton 28 August1987 BSI 08-1
2、999 First published January 1952 First revision July 1966 Second revision August 1987 The following BSI references relate to the work on this standard: Committee reference LBC/27 Draft for comment 86/51616 DC ISBN 0 580 16065 3 Committees responsible for this British Standard The preparation of this
3、 British Standard was entrusted by the Laboratory Apparatus Standards Committee (LBC/-) to Technical Committee LBC/27, upon which the following bodies were represented: Association of Clinical Biochemists British Laboratory Ware Association Department of Health and Social Security Department of Trad
4、e and Industry (Laboratory of the Government Chemist) Department of Trade and Industry (National Weights and MeasuresLaboratory) Glass Manufacturers Federation Institute of Medical Laboratory Sciences Medical Sterile Products Association Ministry of Defence Scientific Glassware Association Society o
5、f Chemical Industry South Western Regional Health Authority Amendments issued since publication Amd. No. Date of issue CommentsBS1132:1987 BSI 08-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Definitions 1 3 Basis of adjustment 1 4 Series of capacities 1 5 To
6、lerances 1 6 Construction 2 7 Inscriptions 4 Appendix A Determination of mean delivered capacity 5 Figure 1 Example of design of automatic pipette up to125mL 2 Figure 2 Example of alternative designs of automatic pipette over250mL 3 Figure 3 Alternative design of overflow cup 4 Table 1 Capacity, tol
7、erances and delivery times 1 Publications referred to Inside back coverBS1132:1987 ii BSI 08-1999 Foreword This British Standard has been prepared under the direction of the Laboratory Apparatus Standards Committee. This British Standard was first published in 1952 and was revised in 1966. This revi
8、sion supersedes the 1966 edition which is withdrawn. In this British Standard the requirements have been aligned with the International Organization for Legal Metrologys draft international document, “Measurement of Volume of LiquidsGlass Delivery Measures (AutomaticPipettes)”, as far as they were k
9、nown at the time. The principal differences between BS1132:1966 and this edition are: a) the extension of the range from100mL to10L; b) the omission of recommended dimensions; c) the omission of the description “Dafert type”. Purchasers ordering to this standard are advised to specify in their purch
10、asing contract that the supplier operates a quality system in compliance with BS5750-3, to assure themselves that the products claimed to comply with BS1132:1987 consistently achieve the required level of quality. A British Standard does not purport to include all the necessary provisions of a contr
11、act. Users of British Standards are responsible for their correct application. 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 to6, an inside back cover a
12、nd a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.BS1132:1987 BSI 08-1999 1 1 Scope This British Standard specifies the requirements for volumetric accuracy, delivery
13、times, capacities, and construction for a range of automatic pipettes which can be used as primary or secondary standards of volume. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purposes of this British Standard the follow
14、ing definitions apply. 2.1 standard reference temperature the temperature at which the automatic pipette is intended to deliver its nominal volume (nominalcapacity) 2.2 datum weir the plane at the upper end of the overflow jet which defines the maximum capacity of the automatic pipette 2.3 capacity
15、the volume, in millilitres or litres, of water, at the standard reference temperature, delivered by the automatic pipette, when determined in accordance with BS6696, supplemented by the information in Appendix A 2.4 delivery time the time occupied by the descent of the water meniscus from the datum
16、weir, with the stopcock in the fully open position, to the point at which it appears to come to rest in the delivery jet 3 Basis of adjustment 3.1 Units The unit of volume shall be either the millilitre or the cubic centimetre for automatic pipettes with a capacity of less than1L. For other automati
17、c pipettes the unit of volume shall be the litre. NOTEThe millilitre is commonly used as a special name for the cubic centimetre, in accordance with the International System of units (SI). 3.2 Reference temperature The standard reference temperature shall be20 C, except when the automatic pipette is
18、 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. 4 Series of capacities The series of nominal capa
19、cities of automatic pipettes shall be as given in column1 of Table 1. NOTECapacities other than those specified are outside the scope of this standard. It is recommended that if automatic pipettes of other capacities are required, they be in accordance with clauses5, 6 and7. However, it should be no
20、ted that compliance with this standard cannot be claimed for such automatic pipettes. Table 1 Capacity, tolerances and deliverytimes 5 Tolerances 5.1 Tolerance on capacity The tolerances on the capacities of the automatic pipettes, when determined in accordance with BS6696, supplemented by Appendix
21、A, shall not exceed the limits shown in column3 of Table 1. 5.2 Tolerance on delivery time The delivery time, when determined with the automatic pipette in a vertical position and the receiving vessel slightly inclined so that the tip of the jet is in contact with the inside of the vessel, but witho
22、ut movement of one against the other, shall be within the limits given in columns4 and5 of Table 1. Capacity Capacity tolerance Delivery time mL (or cm 3 ) 5 10 20 25 50 100 125 150 175 200 250 500 L 1 2 2.5 5 10 mL (or cm 3 ) 0.06 0.08 0.12 0.12 0.15 0.20 0.25 0.3 0.35 0.4 0.4 0.5 1.0 1.0 1.2 2.5 5
23、.0 Minimum s 10 15 15 20 30 30 30 30 30 30 50 60 60 80 80 100 120 Minimum s 20 30 30 40 60 60 60 60 60 60 80 100 100 140 140 150 180BS1132:1987 2 BSI 08-1999 6 Construction 6.1 Material The automatic pipettes shall be manufactured from colourless soda-lime-silica, neutral or borosilicate glass compl
24、ying with class3 or better of BS3473-2. NOTEThe automatic pipettes should be as free as possible from visible defects and reasonably free from internal stress. 6.2 General design The general design of the automatic pipettes shall be as shown in Figure 1 and Figure 2. Figure 1 Example of design of au
25、tomatic pipette up to250mLBS1132:1987 BSI 08-1999 3 Figure 2 Example of alternative designs of automatic pipette over250mLBS1132:1987 4 BSI 08-1999 6.3 Bulb The main body of the bulb of automatic pipettes having a nominal capacity not exceeding250mL (orcm 3 ) shall be cylindrical. The main body of t
26、he bulb of automatic pipettes having a nominal capacity exceeding250mL (orcm 3 ) shall be either cylindrical or spherical. The two ends of the bulb shall merge gradually into the overflow and delivery tubes and the junctions shall be tapered to facilitate drainage. 6.4 Jets 6.4.1 Both the overflow a
27、nd delivery jets shall be constructed with a smooth and gradual taper without a sudden constriction at the orifice. NOTEThe delivery jet should be strongly constructed. 6.4.2 The ends of the jets shall be finished either: a) smoothly ground square with the axis, slightly bevelled on the outside and
28、fire-polished; or b) smoothly ground square with the axis and slightly bevelled on the outside. NOTE 1These methods are listed in order of preference. NOTE 2A fire-polished finish reduces the danger of chipping in use, but should not result in constriction, as indicated in 6.4.1, orin undue stress.
29、6.4.3 The overflow jet shall be either straight, or bent as shown in Figure 1. 6.5 Overflow cup Each automatic pipette shall be provided with an overflow cup which shall be either: a) tapered, as shown in Figure 1 and Figure 2; or b) cylindrical, as shown in Figure 3. A flanged vent hole as shown in
30、 Figure 1 and Figure 2 shall be provided. The overflow cup shall be fitted to the upper tube by a seal to prevent any leakage from the overflow cup. An outflow tube shall be positioned below the level of the datum weir (as shown in Figure 1 and Figure 2). 6.6 Stopcock The stopcock shall be of the do
31、uble oblique bore type and shall allow smooth and precise control of outflow. A stopcock key retaining device shall be fitted. The stopcock, when tested under a head of50cm of water, with the stopcock free from grease but with the barrel and key wet with water and with the key first in one fully shu
32、toff position and then in the other, shall not give a rate of leakage, with the key in either position, in excess of0.006mL/min. When similarly tested with the key of the stopcock in the normal delivery position, the head of water being applied to the filling tube, the rate of leakage shall not exce
33、ed0.006mL/min. The inlet tube shall be bent at right angles in either of the planes illustrated in Figure 1 and Figure 2. 7 Inscriptions The following inscriptions shall be permanently and legibly marked on all automatic pipettes: a) a number indicating the nominal capacity, and adjacent or subadjac
34、ent to this number, the symbol “cm 3 ”, or the symbol “mL”, or the symbol “L”, to indicate the unit in which the pipette is graduated (seenote to3.1); NOTEThe limit of volumetric error according to Table 1 may be marked on all pipettes, for example, by the inscription “ . ml”. b) the inscription “20
35、 C” or“27 C” to indicate the standard reference temperature (see3.2); c) the letters “Ex” to indicate that the pipette has been adjusted to deliver its indicated capacity; d) the makers and/or vendors name or mark; e) the number and year of publication of this British Standard, i.e. “BS1132:1987” 1)
36、 ; f) an identification mark on both the body of the automatic pipette and the stopcock key. Figure 3 Alternative design of overflow cup 1) Marking BS1132:1987 on or in relation to a product is a claim by the manufacturer that the product has been manufactured to the requirements of the standard. Th
37、e accuracy of such a claim is therefore solely the manufacturers responsibility. Enquiries as to the availability of third party certification to support such claims should be addressed to the appropriate authority.BS1132:1987 BSI 08-1999 5 Appendix A Determination of mean delivered capacity NOTEApp
38、endix A describes the method of handling the automatic pipette for the determination of delivered capacity given in BS6696:1986 and replaces paragraph3 of 10.5.1 of that British Standard. A.1 Place the cleaned automatic pipette to be tested, together with an adequate supply of water complying with B
39、S3978, in the test room at least10h before the test, to enable them to stabilize at the test temperature. A.2 Mount the automatic pipette in the vertical position. Using a short length of flexible tubing and a clamp, close the outflow tube. A.3 Fill the automatic pipette with the temperature-stabili
40、zed water until the overflow jet is just submerged. Remove the clamp to allow the excess water to flow away to waste so that the automatic pipette is filled to the datum weir. A.4 Empty the automatic pipette through the delivery jet into a glass vessel slightly inclined so that the tip of the jet is
41、 in contact with the inside of the vessel, but without movement of one against the other throughout the delivery and waiting period. The automatic pipette shall be allowed to empty until the meniscus comes to rest in the jet. To ensure that delivery is complete, a waiting period of approximately3s s
42、hall be observed before removing the receiving vessel. NOTEThe waiting time of3s is specified only for the purpose of this test. 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 removing the pipette from c
43、ontact with the receiving vessel. The first delivery is rejected in order to prime the automatic pipette. A.5 Repeat the filling procedure (seeA.3) and the delivery procedure (seeA.4) using a tared glass receiving vessel to collect the water dispensed by the automatic pipette. A.6 The mass of water
44、dispensed shall be immediately determined in the same environment. A.7 The temperature of the dispensed water shall be determined immediately after the mass has been determined. A.8 The mean delivered capacity shall be calculated from five individual determinations.6 blankBS1132:1987 BSI 08-1999 Pub
45、lications referred to BS3473, Chemical resistance of glass used in the production of laboratory glassware. BS3473-2, Method for determination of hydrolytic resistance of glass grains at98 C. BS3978, Specification for water for laboratory use. BS5750, Quality systems. BS5750-3, Specification for fina
46、l inspection and test 2) . BS5898, Specification for principles of design and construction of volumetric glassware for laboratory use. BS6696, Methods for use and testing of capacity of volumetric glassware. 2) Referred to in the foreword only.BS1132:1987 BSI 389 Chiswick High Road London W4 4AL BSI
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