1、BRITISH STANDARD CONFIRMED MARCH 1988 BS 676:1982 Specification for Flasks with graduated necks (phenols type) UDC 542.3:542.231.3:666.172.7:531.732BS676:1982 This British Standard, having been prepared under the directionof the Laboratory Apparatus Standards Committee,was published underthe authori
2、ty of the BoardofBSI and comes intoeffecton 31August1982 BSI 10-1999 First published June 1936 First revision February 1953 Second revision August 1982 The following BSI references relate to the work on this standard: Committee reference LBC/27 Draft for comment 80/51312 DC ISBN 0 580 11897 5 Cooper
3、ating organizations The Laboratory Apparatus Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: Agricultural Research Council Association for Science Education British Educational Equipment Association British Laboratory War
4、e Association* British Lampblown Scientific Glassware Manufacturers Association Ltd.* British Pharmacopoeia Commission Chemical Industries Association Department of Health and Social Security* Department of Industry (Laboratory of the Government Chemist)* Institute of Petroleum Ministry of Defence*
5、Pharmaceutical Society of Great Britain Royal Society of Chemistry Scientific Instrument Manufacturers Association Society of Chemical Industry* Society of Glass Technology Standardization of Tar Products Tests Committee The organizations marked with an asterisk in the above list, together with the
6、following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Clinical Biochemists Glass Manufacturers Federation Institute of Medical Laboratory Sciences Coopted member Amendments issued since publication Amd. No. Date of iss
7、ue CommentsBS676:1982 BSI 10-1999 i Contents Page Cooperating organizations Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Definition 1 4 Sizes 1 5 Material 1 6 Construction 1 7 Dimensions 1 8 Graduation lines 1 9 Tolerances on capacity 1 10 Alternative scheme of graduation for class B fl
8、asks 2 11 Marking 2 Appendix A Method for the determination of capacity 3 Figure 1 45 ml flask with 5 ml scale 3 Figure 2 150 ml flask with 10 ml scale 4 Figure 3 200 ml flask with 25 ml scale 4 Table 1 Bulb capacities and scales of flasks with graduated necks 1 Table 2 Dimensions for flasks with gr
9、aduated necks 2 Table 3 Tolerances on capacity of graduated necks 2 Publications referred to Inside back coverBS676:1982 ii BSI 10-1999 Foreword This British Standard has been prepared under the direction of the Laboratory Apparatus Standards Committee. It was first published in1936 under the title
10、“Three special flasks with graduated necks” and was revised and correlated with other British Standards for volumetric glassware in1953. This revision specifies three flasks with graduated necks that are primarily intended for the following purposes: 45ml flask with5ml scale, for the polymerization
11、test specified in BS244 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. 200ml flask with 25ml scale, for the determination
12、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 BS5898 and for this reason an alternative standard reference temperature
13、 of27 C is permitted when it is necessary to work at an ambient temperature considerably above20 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 British Standard
14、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 incorporated.
15、 This will be indicated in the amendment table on the inside front cover.BS676:1982 BSI 10-1999 1 1 Scope This British Standard specifies flasks with graduated necks, designed for the special purposes referred to in the foreword. 2 References The titles of the publications referred to in this standa
16、rd are listed on the inside back cover. 3 Definition 3.1 capacity (of an interval on the scale) the additional volume of water at20 C (see note), expressed in millilitres, required to be added to fill the flask, in the manner described inAppendix A, from the zero line to any graduation line correspo
17、nding to the scale interval in question NOTEWhen the flask is required for use in a country which has adopted a reference temperature of27 C (see foreword), this value should be substituted for20 C. 4 Sizes Three sizes of flasks are specified, having the capacities and scales given inTable 1. Table
18、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 annealed. 6 Construction The general shape of the flasks shall be as shown inFigure 1 toFigure 3, the45ml flask having a cylindr
19、ical bulb and the150ml and200ml flasks having a conical bulb. Each flask shall stand vertically on its base without rocking and shall not topple when placed empty on a surface inclined at an angle of15 to the horizontal. The flange at the top of the neck shall be turned over sharply and the mouth sh
20、all not be belled to any considerable distance from the top of the neck. NOTEA ground glass stopper may be fitted to the200ml flask if desired and if so should preferably be one of the sizes specified in BS572. 7 Dimensions The flasks shall conform to the dimensions specified inTable 2. 8 Graduation
21、 lines The graduation lines shall be fine clean permanent lines of uniform thickness not exceeding0.3mm. Marking and filling shall comply with the durability requirements specified in BS3996. NOTEWhere long graduation lines should extend completely round the neck, a gap, not exceeding10% of the circ
22、umference, is permitted. The scales shall be numbered from the bottom upwards with numbering and subdivisions as shown inFigure 1, Figure 2 andFigure 3. The numbered graduation lines and also the lines midway between them on the200ml flask, shall be carried completely round the neck. The shortest gr
23、aduation lines shall be carried half-way round the neck, and the remaining graduation lines shall be intermediate in length and shall project equally at each end beyond the shortest graduation lines. NOTEFor an alternative scheme of graduation suitable for class B flasks, see clause10. 9 Tolerances
24、on capacity The bulb of the flask shall have a capacity approximating to the nominal capacity, within the limits given inTable 2. The tolerances permitted for the graduated necks shall be of two classes, namely class A and class B, as shown inTable 3. The tolerance represents the maximum permissible
25、 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 class A flask of150ml nominal capacity may be in error by 0.04ml at any point, provided that the difference between the errors at any two points does n
26、ot exceed0.04ml. Nominal capacity of bulb Scale Range Subdivision ml ml ml 45 150 200 5 10 25 0.1 0.1 0.2BS676:1982 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 de
27、sired, have graduation lines confined to the front of the neck instead of those specified in clause8. The length of these lines shall be suitably varied so as to emphasize the same lines as are emphasized by the provisions of clause8 and shall comply with the requirements of graduation pattern III o
28、f BS5898:1980. 11 Marking Each flask shall have permanently and legibly marked on it: a) The abbreviation “cm 3 ” or “ml” b) The inscription “In20 C” to indicate that the flask is graduated for content at20 C (see note2). c) An identification number. This inscription is mandatory on class A flasks a
29、nd optional on classB flasks, and shall be repeated on the stopper of the200ml flask if one is provided that does not meet the requirements of BS572. d) The manufacturers and/or vendors name or readily identifiable mark. e) The number of this British Standard, i.e. “BS676” and also the letter “A” or
30、 “B” to indicate the class of accuracy for which the flask has been graduated. NOTE 1Marking BS676 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 solel
31、y the manufacturers responsibility. 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
32、administered by BSI or to the appropriate authority for other certification marks. NOTE 2When the flask is required for use in a country which has adopted a reference temperature of27 C (see foreword and clause4), this temperature should be substituted for20 C. Table 3 Tolerances on capacity of grad
33、uated necks Dimensions Nominal capacity 45 ml 150 ml 200 ml Capacity of flask to zero graduation line ml 45 (minimum) 150 7 200 10 Minimum distance of highest graduation line from top of neck mm 15 20 25 Length of scale mm 50 to 60 150 to 170 125 to 150 a Minimum length of neck below lowest graduati
34、on line mm 3 10 10 a Maximum length of neck mm 205 190 Overall height mm 162 3 External diameter of bulb at widest part mm 36 2 75 3 83 3 Approximate diameter of base mm 55 60 a Measured to the point at which the neck begins to expand at the junction with the bulb. Nominal capacity of bulb Tolerance
35、 on capacity of neck Class A Class B ml ml ml 45 150 200 0.04 0.04 0.1 0.08 0.08 0.2BS676:1982 BSI 10-1999 3 Appendix A Method for the determination of capacity When determining the capacity of any interval on the scale the flask shall first be thoroughly cleaned and dried. If hot air is used to has
36、ten 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 avoid wetting the neck of the flask above the water
37、 surface and also to avoid trapping any air bubbles on the walls of the flask. The lowest point of the water meniscus 1)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 jet at its lower end. The apparent mass in air of t
38、he 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 determined. All operations shall be carried out at room
39、 temperature. The volume of water contained by the flask at20 C 2)between the zero line and the graduation line tested, shall be calculated from the apparent mass of air thus determined (see BS1797), by applying a correction for water temperature. 1) The meniscus can be clearly defined by folding a
40、strip of black paper round the neck, the top edge of the paper being not more than1mm 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 the reference temperature. NOTEWhere 27 C has been cho
41、sen as the reference temperature (see clause4) the inscription “In 20 C” should be replaced by “In 27 C”. Figure 1 45 ml flask with 5 ml scaleBS676:1982 4 BSI 10-1999 NOTEWhere27 C has been chosen as the reference temperature (see clause4) the inscription “In 20 C” should be replaced by “In27 C”. Fi
42、gure 2 150 ml flask with 10 ml scale NOTEWhere27 C has been chosen as the reference temperature (see clause4) the inscription “In20 C” should be replaced by “In 27 C”. Figure 3 200 ml flask with 25 ml scaleBS676:1982 BSI 10-1999 Publications referred to BS 244 & BS 290, Turpentine for paints. BS 572
43、, Interchangeable conical 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 pr
44、inciples of design and construction of volumetric glassware for laboratory use. BS 676:1982 BSI 389 Chiswick High Road London W4 4AL BSIBritishStandardsInstitution BSI is the independent national body responsible for preparing BritishStandards. It presents the UK view on standards in Europe and at t
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