BS 615-1953 Specification for Kohlrausch flasks《凯氏量瓶规范》.pdf

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1、BRITISH STANDARD CONFIRMED JANUARY 1993 BS 615:1953 Incorporating Amendment Nos. 1 and 2 Specification for Kohlrausch flasksBS615:1953 This British Standard, having beenapproved by the Scientific Glassware and Related LaboratoryApparatus IndustryStandards Committee and endorsed by the Chairman ofthe

2、 Chemical Divisional Council, was published under theauthority of the General Council on 14 July 1953 BSI 02-2000 First published February 1936 First revision July 1953 ISBN 0 580 34398 7 Co-operating organizations The Scientific Glassware and Related Laboratory Apparatus Industry Standards Committe

3、e, 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 Br

4、itish Association for the Advancement of Science* British Chemical Ware Manufacturers Association* British Laboratory Ware Association* British Lampblown Scientific Glassware Manufacturers Association* British Pharmacopoeia Commission British Scientific Instrument Research Association Chemical Socie

5、ty Department 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

6、 Royal 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 marke

7、d with 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 High Commission of India Metropolitan Water Board Universit

8、y of London (Faculty of Science) Individual manufacturers Amendments issued since publication Amd. No. Date of issue Comments 1767 December 1953 4919 May 1963 Indicated by a sideline in the marginBS615:1953 BSI 02-2000 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope

9、 1 2 Sizes 1 3 Definition of capacity 1 4 Material 1 5 Construction 1 6 Dimensions 1 7 Graduation mark 2 8 Tolerances on capacity 2 9 Inscriptions 2 Appendix A Testing of British Standard Kohlrausch flasks 3 Appendix B Method for the determination of capacity 3 Figure 1 British Standard Kohlrausch f

10、lask 4 Table 1 Mandatory dimensions for Kohlrausch flasks 1 Table 2 Recommended dimensions for Kohlrausch flasks 1 Table 3 Tolerances on capacity for Kohlrausch flasks 2BS615:1953 ii BSI 02-2000 Foreword This standard makes reference to the following British Standards: BS 675, Sugar flasks. BS 1797,

11、 Tables for use in the calibration of volumetric glassware. This British Standard specifies three sizes of flask, suitable for use in viscosity determination and chemical analysis, and in particular for the following purposes: 50 ml. flask the determination of the viscosity of oils by means of the R

12、edwood apparatus. 100 ml. flask the analysis of sugars. 1) 200 ml. flask the determination of the viscosity of oils by means of the Engler apparatus. This British Standard was first published in1936. At that time three special sizes of flask for use in the sugar industry were included, but in view o

13、f the negligible demand for these in recent years they have now been omitted. The present revision has been brought into line with other specifications for volumetric glassware published since1949, by listing only the essential dimensions as mandatory and including the others for the guidance of man

14、ufacturers. Tests have shown that the requirement in Clause5 regarding stability on an inclined plane is readily satisfied by good quality flasks in current production. It has been suggested that after further consideration by the manufacturers it may be possible to increase the specified minimum an

15、gle of “topple” from10 to15 . 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 acceptance of20 C. as the s

16、tandard 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 temperature of27 C.” In

17、 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 and 9, toAppendix B, and toFigure 1. In accordance with

18、the recommendations of Committee ISO/TC48 use of the inscription “In” is now recommended in place of “C” to indicate that the flask 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 purp

19、ort to include all the necessary provisions of a contract. 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 c

20、over, pages i and ii, pages1 to 4, an inside back cover and 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. 1) A modified Kohlrausch flask of greater accuracy, intende

21、d for polarization work on raw and refined sugar, is specified in BS675, “Sugar flasks”.BS615:1953 BSI 02-2000 1 1 Scope This British Standard specifies a range of Kohlrausch flasks suitable for use in viscosity determination and chemical analysis. 2 Sizes Three sizes of flask are specified, of capa

22、city50,100and200ml. respectively. 3 Definition of capacity The capacity of the flask is defined as the volume of water at20 C., expressed in millilitres, contained by the flask at20 C., when determined as described inAppendix B. 4 Material The flask shall be made of clear glass, as free as possible

23、from visible defects, and shall be well annealed. 5 Construction The general shape of the flask shall be as shown inFigure 1. It shall stand vertically on its base without rocking and shall not topple when placed empty on a surface inclined at an angle of10 to the horizontal. The junction between th

24、e wide and narrow parts of the neck shall be such as to facilitate the flow of liquid down the wall and there shall be no shoulder on which liquid can lodge. 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

25、the neck. The flask shall be sufficiently robust in construction to withstand normal usage and the wall thickness shall show no gross departures from uniformity. 6 Dimensions The only mandatory dimensions for British Standard Kohlrausch flasks are those specified inTable 1. Table 2 provides for the

26、guidance of manufacturers further recommended dimensions suitable for Kohlrausch flasks. These dimensions are not a mandatory part of the specification, but a flask which, on visual inspection, shows any gross departure from them shall be deemed not to comply with the specification. Table 1 Mandator

27、y dimensions for Kohlrausch flasks Table 2 Recommended dimensions for Kohlrausch flasks All dimensions are in millimetres Dimension Nominal capacity 50 ml. 100 ml. 200 ml. a) Internal diameter of narrow part of neck Classes A and B minimum 8 10 12 Class A maximum 10 12 14 Class B maximum 12 14 16 b)

28、 Length of tube of uniform bore above and below graduation mark minimum 5 5 6 c) Diameter of base minimum 27 34 40 All dimensions are in millimetres Dimension Nominal capacity 50 ml. 100 ml. 200 ml. d) Internal diameter of wide part of neck 25 25 30 e) Length of cylindrical portion of narrow part of

29、 neck 30 35 40 f) Distance from top of narrow part of neck to top of wide part 45 53 63 g) Overall height 127 155 185BS615:1953 2 BSI 02-2000 7 Graduation mark The graduation mark shall be a fine clean permanent line of uniform thickness, completely encircling the neck of the flask and lying in a pl

30、ane parallel to the base. 8 Tolerances on capacity Two sets of tolerances are specified, namely Class A and Class B, as shown inTable 3. Table 3 Tolerances on capacity for Kohlrausch flasks 9 Inscriptions Each flask shall have permanently and legibly marked on it: a) The nominal capacity of the flas

31、k,e.g.“100ml.” b) Either the inscription “In20 C” or the inscription “C20 C” to indicate that the flask is graduated for content at20 C. c) An identification number, which is mandatory on Class A flasks and optional on Class B flasks. d) The makers or vendors name or mark. e) The number of this Brit

32、ish Standard, i.e.“BS615”, 2)and also the letter “A7” or “B” to indicate the class of accuracy for which the flask has been graduated. Tolerance Nominal capacity 50 ml. 100 ml. 200 ml. Class A ml. 0.04 0.06 0.1 Class B ml. 0.06 0.1 0.2 2) The mark “BS615” on the product is an indication by the manuf

33、acturer that it purports 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 “B

34、S615” on a product is 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 wi

35、th all the requirements 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 licensed manufacturer.BS615:1953 BSI 02-2000 3 Appendix A Test

36、ing of British Standard Kohlrausch flasks The National Physical Laboratory is prepared to accept flasks for examination for compliance with the Class A requirements of this British Standard. Certificates of values will be issued for satisfactory Class A flasks, if required. Particulars of the fees c

37、harged can be obtained on application to the Director, National Physical Laboratory, Teddington, Middlesex. Appendix B Method for the determination of capacity When determining the capacity of a flask the vessel shall first be thoroughly cleaned and dried. If hot air is used to speed up the process

38、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 water to a few millimetres above the graduation mark, care being taken to avoid wetting the neck of the flask above the water surface and also to

39、 avoid trapping any air bubbles on the walls of the flask. The lowest point of the water meniscus 3)shall be adjusted to the top edge of the graduation mark 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

40、then be determined. All operations shall be carried out at room temperature. The volume of water contained by the flask at20 C. shall be calculated from the weight thus determined by applying corrections for water temperature and, where necessary, air temperature and pressure (see BS 1797 4) ). 3) T

41、he 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. below the graduation mark. The meniscus, so shaded, is viewed against a white background. 4) BS 1797, “Tables for use in the calibration of volumetric glassware”.BS6

42、15:1953 4 BSI 02-2000 The lettered dimensions refer to Table 1 and Table 2 Figure 1 British Standard Kohlrausch flaskBS615:1953 BSI 02-2000 British Standards The following are available on application: YEARBOOK Including subject index and numerical list of British Standards 12s. 6d. SECTIONAL LISTS.

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