1、BRITISH STANDARD CONFIRMED JANUARY 1993 BS 675:1953 Incorporating Amendments Nos. 1 and 2 Specification for Sugar flasksBS675:1953 This British Standard, having been approved by the ScientificGlassware and RelatedLaboratory ApparatusIndustry StandardsCommittee and endorsed by the Chairman of theChem
2、ical Divisional Council,was published under theauthority of the General Council on 11February 1953 BSI 02-2000 First published June 1936 First revision February 1953 ISBN 0 580 34572 6 Co-operating organizations The Scientific Glassware and Related Laboratory Apparatus Industry Standards Committee,
3、under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: Admiralty* Air Ministry Association of British Chemical Manufacturers* Association of Scientific Workers Board of Trade Briti
4、sh Association for the Advancement of Science* British Chemical Ware Manufacturers Association* British Laboratory Ware Association* British Lampblown Scientific Glassware Manufacturers Association* British Pharmacopia Commission British Scientific Instrument Research Association Chemical Society De
5、partment of the Government Chemist* D.S.I.R. Chemical Research Laboratory Glass Manufacturers Federation* Institute of Petroleum* Ministry of Education Ministry of Health* Ministry of Supply* National Physical Laboratory* Oil Companies Materials Committee Pharmaceutical Society of Great Britain Roya
6、l Institute of Chemistry* Science Masters Association Society of Chemical Industry Society of Glass Technology* Society of Public Analysts and Other Analytical Chemists* Standardization of Tar Products Tests Committee* The Government departments and scientific and industrial organizations marked wit
7、h an asterisk in the above list, together with the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of Hospital Management Committees Guild of Public Pharmacists Metropolitan Water Board Office of the High Commissioner for Ind
8、ia University of London (Faculty of Science) Individual manufacturers Amendments issued since publication Amd. No. Date of issue Comments 1776 December 1953 4899 April 1963 Indicated by a sideline in the marginBS675:1953 BSI 02-2000 i Contents Page Co-operating organizations Inside front cover Forew
9、ord ii 1 Scope 1 2 Types and sizes 1 3 Definition of capacity 1 4 Material 1 5 Construction 1 6 Dimensions 1 7 Graduation marks 2 8 Tolerances on capacity 2 9 Inscriptions 2 Appendix A Testing of British Standard sugar flasks 3 Appendix B Method for the determination of capacity 3 Figure 1 Type 1 su
10、gar flasks 4 Figure 2 Type 2 sugar flasks 4 Table 1 Mandatory dimensions for sugar flasks 1 Table 2 Tolerances for sugar flasks 2BS675:1953 ii BSI 02-2000 Foreword This standard makes reference to the following British Standards: BS 615, Kohlrausch flasks. BS 1797, Tables for use in the calibration
11、of volumetric glassware. This British Standard, which was first published in1936, specifies two types of flask for use in sugar analysis: a type with two graduation marks suitable for the analysis of sugar factory juices; and a type of greater accuracy, with one graduation mark, suitable for the pol
12、arization of sugars. The flasks with two graduation marks are provided in three sizes, of50/55ml.,100/110ml. and200/220ml. capacity respectively. The dimensions are based on a specification drawn up in1932 by the South African Sugar Technologists Association in which particular importance was attach
13、ed to the provision of an adequate air space above the upper graduation mark to ensure thorough mixing of the contents of a flask on shaking. In order to provide the air space considered necessary, without making the flasks unduly tall, the necks are made rather wide, but the accuracy of the flasks
14、fully meets the requirements of juice analysis. The shape adopted for the bulb gives a wide base and minimizes the tendency for bubbles to cling to the walls below the neck. A single graduation mark only is required for the polarization of sugars and thehigh degree of accuracy needed demands a narro
15、w neck. Ordinary straight-necked volumetric flasks have been used for this purpose and also Kohlrausch flasks, described in BS615. A special100ml. flask, the Mann sugar flask, was included in the1936 edition of this standard, but subsequent experience has shown that it does not satisfy all requireme
16、nts. The polarization flask now specified has been designed to include the best features of the various flasks previously in use and has been approved after test by sugar technologists representing the biggest users in the country. The design allows the maximum possible accuracy combined with conven
17、ience in use. The flask combines narrowness of neck at the graduation mark with an upper enlargement, which is a safeguard against overflow when sugar is being washed into the flask and also provides adequate space for mixing when the flask is shaken. It has also the practical advantage that it can
18、be closed with the thumb and shaken with one hand with the utmost ease and with complete assurance that no liquid escapes during the shaking. The pear-shaped bulb is considered more convenient than the conical or rounded form. In this revision no minimum weights for the flasks have been included, an
19、d instead a robust flask is specified in Clause5. SUBSIDIARY STANDARD TEMPERATURE OF 27 C. At the Second Meeting, in1951, of Technical Committee ISO/TC48 Laboratory Glassware and Related Apparatus, of the International Organization for Standardization, it was agreed to qualify as follows the accepta
20、nce of20 C. as the standard temperature for volumetric glassware: “When it is necessary in tropical countries to work at an ambient temperature considerably above20 C., and these countries do not wish to use exclusively the standard temperature of20 C., it is recommended that they should adopt a tem
21、perature of27 C.” In order to meet the requirements of such tropical countries it has been decided to amend the British Standards for volumetric glassware to permit27 C., as an alternative to20 C. In the present British Standard this amendment applies to Clauses3 and9, toAppendix B, and toFigure 1 a
22、ndFigure 2.BS675:1953 BSI 02-2000 iii In accordance with the recommendations of Technical Committee ISO/TC48 Laboratory Glassware and Related Apparatus, of the International Organization for Standardization (ISO), use of the inscription “In” is now recommended in place of “C” to indicate that the fl
23、ask is graduated “to contain”. It is intended that this change shall become mandatory, when a revised edition of the standard is published. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct applicat
24、ion. 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 toiv, pages1to4, an inside back cover and a back cover. This standard has been updated (see copyright date) and may
25、 have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS675:1953 BSI 02-2000 1 1 Scope This British Standard specifies two types of graduated flask suitable for use in sugar analysis. 2 Types and sizes Two types of sugar flask are specifie
26、d, as follows: Type 1, in which the flask is provided with2 graduation marks. Three sizes are specified, of nominal capacity50/55ml.,100/110ml. and200/220ml. respectively, as illustrated inFigure 1. Type 2, in which the flask is provided with a single graduation mark and the neck is widened at the t
27、op to form a cup. One size is specified, of nominal capacity100ml., as illustrated inFigure 2. 3 Definition of capacity The capacity of the flask corresponding to a given graduation mark is defined as the volume of water at20 C., expressed in millilitres, required to fill the flask to that mark at20
28、 C., when determined as described inAppendix B. 4 Material The flask shall be made of clear glass, as free as possible from visible defects, and shall be well annealed. 5 Construction Each flask shall be of pear shape with a wide base as shown inFigure 1 andFigure 2. The edge of the base shall be sl
29、ightly ground so that the flask stands firmly without rocking. The flask shall not topple when placed empty on a surface inclined at an angle of10 to the horizontal. The neck or that portion of it bearing the graduation mark shall be cylindrical and the upper end shall be fused and slightly flanged.
30、 The flask shall be sufficiently robust in construction to withstand normal usage and the wall thickness shall show no local departures from uniformity. 6 Dimensions The flasks shall conform to the appropriate dimensions given inTable 1. Table 1 Mandatory dimensions for sugar flasks All dimensions a
31、re in millimetres Dimension Nominal capacity Type 1 Type 2 50/55 ml. 100/110 ml. 200/220 ml. 100 ml. Overall height, not to exceed 150 195 240 165 Diameter of base, to be at least 30 40 50 40 Length of cylindrical neck belowlowergraduation mark, tobeatleast 5 5 5 Distance between graduation marks,to
32、beat least 35 45 55 Distance from upper graduation marktotop of neck, to be at least 40 50 60 Length of cylindrical neck aboveandbelow graduation mark,tobe at least 5 Length of wide part of neck, to be at least 50 Length of narrow part of neck, tobeatleast 25 Internal diameter of wide part of neck 1
33、6 1 Internal diameter of narrow part of neck 9.5 0.5BS675:1953 2 BSI 02-2000 7 Graduation marks The graduation marks shall be fine cleanly etched permanent lines of uniform thickness, extending completely round the neck, lying in planes at right angles to the axis of the neck and horizontal when the
34、 flask is standing on a level surface. On Type1 flasks each graduation mark shall be appropriately numbered as shown inFigure 1. 8 Tolerances on capacity Two sets of tolerances are specified for Type1 flasks, namely Class A and Class B, as shown inTable 2. One tolerance only is provided for Type2 fl
35、asks as shown inTable 2. 9 Inscriptions Each flask shall have permanently and legibly marked on it: a) Either (for Type 1 flasks) the abbreviation “ml.” to signify that the flask is calibrated in terms of the millilitre, or (for Type2 flasks) the nominal capacity of the flask, i.e.“100ml.” b) Either
36、 the inscription “In20 C” or the inscription “C20 C” to indicate that the flask is graduated for content at20 C. c) An identification number. This inscription is mandatory on Class A flasks of Type1 and on flasks of Type2 and is optional on Class B flasks of Type1. d) The makers or vendors name or m
37、ark. e) The number of this British Standard, i.e.“BS675”, 1)and also, on Type1 flasks, the letter “A” or “B” to indicate the class of accuracy for which the flask has been graduated. Table 2 Tolerances for sugar flasks 1) The mark BS675 on the product, is an indication by the manufacturer that it pu
38、rports to comply with the requirements of this British Standard. The British Standards Institution is the owner of the registered certification mark shown below: which can be used by manufacturers only under licence from the BSI. The presence of this mark in addition to the mark BS675 on a product i
39、s an assurance that the product does in fact comply with the requirements of the Standard. It indicates that the BSI has satisfied itself, by inspection and testing, that the system of production, supervision and control used by the manufacturer is such as to ensure compliance with all the requireme
40、nts of the Standard. Maintenance of this approved system is secured by periodical inspection and testing on behalf of the BSI. The mark must be accompanied by the name or registered trade mark or licence number of the licenced manufacturer. Further particulars of the terms of licence may be obtained
41、 from the Director, the British Standards Institution,24 Victoria Street,SW1. Tolerance Nominal capacity Type 1 Type 2 50/55 ml. 100/110 ml. 200/220 ml. 100 ml. Class A Class B Class A Class B Class A Class B Maximum error allowed at any graduation mark ml. 0.06 0.1 0.1 0.15 0.15 0.25 0.03 Maximum d
42、ifference allowed between errors at the two graduation marks ml. 0.06 0.1 0.1 0.15 0.15 0.25 BS675:1953 BSI 02-2000 3 Appendix A Testing of BritishStandardsugar flasks The National Physical Laboratory is prepared to accept Class A flasks of Type1 and flasks of Type2 for examination for compliance wi
43、th the requirements of this British Standard. Certificates of values will be issued for satisfactory flasks, if required. Particulars of the fees charged can be obtained on application to the Director, National Physical Laboratory, Teddington, Middlesex. Appendix B Method for the determinationof cap
44、acity When determining the capacity of a flask the vessel shall first be thoroughly cleaned and dried. If hot air is used to hasten the process of drying, care shall be taken that the flask settles down to room temperature before testing. The clean weighed flask shall then be filled with distilled w
45、ater to a few millimetres above the graduation mark to be tested, care being taken to avoid wetting the neck of the flask above the water surface and also to avoid trapping air bubbles on the walls of the flask. The lowest point of the water meniscus 2)shall be adjusted to the top edge of the gradua
46、tion mark to be tested by withdrawing small amounts of water by means of a glass tube drawn out to a jet at its lower end. The weight of the water in the flask shall then be determined. All operations shall be carried out at room temperature. The volume of water contained by the flask at20 C. shall
47、be calculated from the weight thus determined by applying corrections for water temperature, and, where necessary, air temperature and pressure (seeBS1797 3) ). 2) 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 than1mm.
48、below the graduation mark on which the setting is to be made. The meniscus, so shaded, is viewed against a white background. 3) BS1797. “Tables for use in the calibration of volumetric glassware”.BS 675:1953 4 BSI 02-2000 Figure 1 Type 1 sugar flask Figure 2 Type 2 sugar flaskBS675:1953 BSI 02-2000
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