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1、BRITISH STANDARD CONFIRMED MARCH 1988 BS 676:1982 Specification for Flasks with graduated necks (phenols type) UDC 542.3:542.231.3:666.172.7:531.732 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 This British Standard, having be
2、en prepared under the direction of the Laboratory Apparatus Standards Committee, was published under the authority of the Board of BSI and comes into effect on 31 August 1982 BSI 10-1999 First published June 1936 First revision February 1953 Second revision August 1982 The following BSI references r
3、elate to the work on this standard: Committee reference LBC/27 Draft for comment 80/51312 DC ISBN 0 580 11897 5 Cooperating organizations The Laboratory Apparatus Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Agricultur
4、al Research Council Association for Science Education British Educational Equipment Association British Laboratory Ware Association* British Lampblown Scientific Glassware Manufacturers Association Ltd.* British Pharmacopoeia Commission Chemical Industries Association Department of Health and Social
5、 Security* Department of Industry (Laboratory of the Government Chemist)* Institute of Petroleum Ministry of Defence* Pharmaceutical Society of Great Britain Royal Society of Chemistry Scientific Instrument Manufacturers Association Society of Chemical Industry* Society of Glass Technology Standardi
6、zation of Tar Products Tests Committee The organizations marked with an asterisk in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Clinical Biochemists Glass Manufacturers Feder
7、ation Institute of Medical Laboratory Sciences Coopted member Amendments issued since publication Amd. No.Date of issueComments Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 BSI 10-1999i Contents Page Cooperating organizationsI
8、nside front cover Forewordii 1Scope1 2References1 3Definition1 4Sizes1 5Material1 6Construction1 7Dimensions1 8Graduation lines1 9Tolerances on capacity1 10Alternative scheme of graduation for class B flasks2 11Marking2 Appendix A Method for the determination of capacity3 Figure 1 45 ml flask with 5
9、 ml scale3 Figure 2 150 ml flask with 10 ml scale4 Figure 3 200 ml flask with 25 ml scale4 Table 1 Bulb capacities and scales of flasks with graduated necks1 Table 2 Dimensions for flasks with graduated necks2 Table 3 Tolerances on capacity of graduated necks2 Publications referred toInside back cov
10、er Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 ii BSI 10-1999 Foreword This British Standard has been prepared under the direction of the Laboratory Apparatus Standards Committee. It was first published in 1936 under the titl
11、e “Three special flasks with graduated necks” and was revised and correlated with other British Standards for volumetric glassware in 1953. This revision specifies three flasks with graduated necks that are primarily intended for the following purposes: 45 ml flask with 5 ml scale, for the polymeriz
12、ation test specified in BS 244 and for the determination of small quantities of phenols in light and middle oils, in refined lower boiling point products and in creosote oils, by the official methods of the Standardization of Tar Products Tests Committee. 200 ml flask with 25 ml scale, for the deter
13、mination of phenols in light and middle oils, in refined lower boiling point products and in creosote oils, by the official methods of the Standardization of Tar Products Tests Committee. The flasks have been designed in accordance with BS 5898 and for this reason an alternative standard reference t
14、emperature of 27 C is permitted when it is necessary to work at an ambient temperature considerably above 20 C. 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. Compliance with a Briti
15、sh Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments i
16、ncorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 BSI 10-19991 1 Scope This British Standard specifies flasks with graduated necks, designed for
17、the special purposes referred to in the foreword. 2 References The titles of the publications referred to in this standard are listed on the inside back cover. 3 Definition 3.1 capacity (of an interval on the scale) the additional volume of water at 20 C (see note), expressed in millilitres, require
18、d to be added to fill the flask, in the manner described in Appendix A, from the zero line to any graduation line corresponding to the scale interval in question NOTEWhen the flask is required for use in a country which has adopted a reference temperature of 27 C (see foreword), this value should be
19、 substituted for 20 C. 4 Sizes Three sizes of flasks are specified, having the capacities and scales given in Table 1. Table 1 Bulb capacities and scales of flasks with graduated necks 5 Material The flasks shall be made of clear glass, as free as possible from visible defects, and shall be well ann
20、ealed. 6 Construction The general shape of the flasks shall be as shown in Figure 1 to Figure 3, the 45 ml flask having a cylindrical bulb and the 150 ml and 200 ml flasks having a conical bulb. Each flask shall stand vertically on its base without rocking and shall not topple when placed empty on a
21、 surface inclined at an angle of 15 to the horizontal. The flange at the top of the neck shall be turned over sharply and the mouth shall not be belled to any considerable distance from the top of the neck. NOTEA ground glass stopper may be fitted to the 200 ml flask if desired and if so should pref
22、erably be one of the sizes specified in BS 572. 7 Dimensions The flasks shall conform to the dimensions specified in Table 2. 8 Graduation lines The graduation lines shall be fine clean permanent lines of uniform thickness not exceeding 0.3 mm. Marking and filling shall comply with the durability re
23、quirements specified in BS 3996. NOTEWhere long graduation lines should extend completely round the neck, a gap, not exceeding 10 % of the circumference, is permitted. The scales shall be numbered from the bottom upwards with numbering and subdivisions as shown in Figure 1, Figure 2 and Figure 3. Th
24、e numbered graduation lines and also the lines midway between them on the 200 ml flask, shall be carried completely round the neck. The shortest graduation lines shall be carried half-way round the neck, and the remaining graduation lines shall be intermediate in length and shall project equally at
25、each end beyond the shortest graduation lines. NOTEFor an alternative scheme of graduation suitable for class B flasks, see clause 10. 9 Tolerances on capacity The bulb of the flask shall have a capacity approximating to the nominal capacity, within the limits given in Table 2. The tolerances permit
26、ted for the graduated necks shall be of two classes, namely class A and class B, as shown in Table 3. The tolerance represents the maximum permissible error at any point on the scale and also the maximum permissible difference between the errors at any two points. Thus, for example, the scale of a c
27、lass A flask of 150 ml nominal capacity may be in error by 0.04 ml at any point, provided that the difference between the errors at any two points does not exceed 0.04 ml. Nominal capacity of bulb Scale RangeSubdivision mlmlml 45 150 200 5 10 25 0.1 0.1 0.2 Licensed Copy: sheffieldun sheffieldun, na
28、, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 2 BSI 10-1999 Table 2 Dimensions for flasks with graduated necks 10 Alternative scheme of graduation for class B flasks Flasks intended to comply with the class B tolerances may, if desired, have graduation lines confined t
29、o the front of the neck instead of those specified in clause 8. The length of these lines shall be suitably varied so as to emphasize the same lines as are emphasized by the provisions of clause 8 and shall comply with the requirements of graduation pattern III of BS 5898:1980. 11 Marking Each flask
30、 shall have permanently and legibly marked on it: a) The abbreviation “cm3” or “ml” b) The inscription “In 20 C” to indicate that the flask is graduated for content at 20 C (see note 2). c) An identification number. This inscription is mandatory on class A flasks and optional on class B flasks, and
31、shall be repeated on the stopper of the 200 ml flask if one is provided that does not meet the requirements of BS 572. d) The manufacturers and/or vendors name or readily identifiable mark. e) The number of this British Standard, i.e. “BS 676” and also the letter “A” or “B” to indicate the class of
32、accuracy for which the flask has been graduated. NOTE 1Marking BS 676 on or in relation to a product is a claim by the manufacturer that the product has been manufactured in accordance with the requirements of the standard. The accuracy of such a claim is therefore solely the manufacturers responsib
33、ility. Enquiries as to the availability of third party certification to support such claims should be addressed to the Director, Quality Assurance Division, British Standards Institution, Maylands Avenue, Hemel Hempstead, Herts HP2 4SQ in the case of certification marks administered by BSI or to the
34、 appropriate authority for other certification marks. NOTE 2When the flask is required for use in a country which has adopted a reference temperature of 27 C (see foreword and clause 4), this temperature should be substituted for 20 C. Table 3 Tolerances on capacity of graduated necks Dimensions Nom
35、inal capacity 45 ml150 ml200 ml Capacity of flask to zero graduation lineml45 (minimum) 150 7200 10 Minimum distance of highest graduation line from top of neck mm152025 Length of scalemm50 to 60150 to 170125 to 150 aMinimum length of neck below lowest graduation line mm31010 aMaximum length of neck
36、 mm205190 Overall heightmm162 3 External diameter of bulb at widest partmm36 275 383 3 Approximate diameter of basemm5560 a Measured to the point at which the neck begins to expand at the junction with the bulb. Nominal capacity of bulb Tolerance on capacity of neck Class AClass B mlmlml 45 150 200
37、0.04 0.04 0.1 0.08 0.08 0.2 Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 BSI 10-19993 Appendix A Method for the determination of capacity When determining the capacity of any interval on the scale the flask shall first be thor
38、oughly cleaned and dried. If hot air is used to hasten the process of drying, care shall be taken to ensure that the flask settles down to room temperature before testing. The clean weighed flask shall then be filled with distilled water to a few millimetres above the zero line, care being taken to
39、avoid wetting the neck of the flask above the water surface and also to avoid trapping any air bubbles on the walls of the flask. The lowest point of the water meniscus1) shall be adjusted to the top edge of the zero line by withdrawing small amounts of water by means of a glass tube drawn out to a
40、jet at its lower end. The apparent mass in air of the water in the flask shall then be determined. More distilled water shall be added to the flask and the meniscus adjusted by the same method to the graduation line to be tested, and the apparent mass in air of water in the flask shall again be dete
41、rmined. All operations shall be carried out at room temperature. The volume of water contained by the flask at 20 C2) between the zero line and the graduation line tested, shall be calculated from the apparent mass of air thus determined (see BS 1797), by applying a correction for water temperature.
42、 1) The meniscus can be clearly defined by folding a strip of black paper round the neck, the top edge of the paper being not more than 1 mm below the graduation line on which the setting is to be made. The meniscus, so shaded, is viewed against a white background. 2) Or 27 C where this is chosen as
43、 the reference temperature. NOTEWhere 27 C has been chosen as the reference temperature (see clause 4) the inscription “In 20 C” should be replaced by “In 27 C”. Figure 1 45 ml flask with 5 ml scale Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c
44、) BSI BS 676:1982 4 BSI 10-1999 NOTEWhere 27 C has been chosen as the reference temperature (see clause 4) the inscription “In 20 C” should be replaced by “In 27 C”. Figure 2 150 ml flask with 10 ml scale NOTEWhere 27 C has been chosen as the reference temperature (see clause 4) the inscription “In
45、20 C” should be replaced by “In 27 C”. Figure 3 200 ml flask with 25 ml scale Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 BSI 10-1999 Publications referred to BS 244 & BS 290, Turpentine for paints. BS 572, Interchangeable co
46、nical ground glass joints. BS 1797, Tables for use in calibration of volumetric glassware. BS 3996, Specification for colour coding for one-mark and graduated pipettes (including requirements for the service performance of the colour coding enamels). BS 5898, Specification for principles of design a
47、nd construction of volumetric glassware for laboratory use. Licensed Copy: sheffieldun sheffieldun, na, Wed Dec 06 14:03:42 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 676:1982 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsib
48、le for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendment
49、s or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: 020 8996 9000. Fax: 020 8996 7400. BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest edition
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