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1、BRITISH STANDARD BS 5471:1977 Incorporating Amendment No. 1 Specification for Thermometer for use with alcohol hydrometers UDC 536.512:531.756.3:542.3:661.722 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5471:1977 This British Standard
2、, having been prepared under the direction of the Laboratory Apparatus Standards Committee, was published under the authority of the Executive Board on 31 March 1977 BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference LBC/4 Draft for comment 76/54426 ISB
3、N 0 580 09832 X Cooperating organizations The Laboratory Apparatus Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific, industrial and consumer organizations: Agricultural Research Counc
4、il Association for Science Education Association of Technical, Scientific and Managerial Staffs British Laboratory Ware Association* British Lampblown Scientific Glassware Manufacturers Association Ltd.* British Pharmacopoeia Commission Chemical Industries Association* Chemical Society, Analytical D
5、ivision Department of Health and Social Security* Department of Industry, Laboratory of The Government Chemist* Department of Industry, National Physical Laboratory* Glass Manufacturers Federation Institute of Petroleum* Ministry of Defence* Pharmaceutical Society of Great Britain Scientific Instrum
6、ent Manufacturers Association Society of Chemical Industry Society of Glass Technology Standardization of Tar Products Tests Committee The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represen
7、ted on the committee entrusted with the preparation of this British Standard: British Medical Association Meteorological Office Amendments issued since publication Amd. No.Date of issueComments 2788March 1979Indicated by a sideline in the margin Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01
8、 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5471:1977 BSI 09-1999i Contents Page Cooperating organizationsInside front cover Forewordii 1Scope1 2References1 3Type, range and graduation interval1 4Temperature scale1 5Immersion1 6Glass1 7Liquid filling1 8Gas filling1 9Construction1 10Marki
9、ng2 11Accuracy3 12Inscriptions3 Appendix A List of approved NPL glasses4 Appendix B Testing of British Standard thermometers4 Table 1 Dimensions for thermometers for use with alcohol hydrometers2 Table 2 Thermometric glasses approved by the National Physical Laboratory (1977)4 Publications referred
10、to6 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5471:1977 ii BSI 09-1999 Foreword This British Standard was published under the authority of the Laboratory Apparatus Standards Committee following consultations between Government depar
11、tments, manufacturers, and users of alcohol hydrometers. It was prepared at the request of HM Customs and Excise in support of an intended statutory instrument to implement a Council Directive of the EEC1), and covers only the thermometer which is expected to be used in the United Kingdom. It thus e
12、xcludes enclosed-scale glass thermometers and thermometers with a graduation interval of 0.1 C or 0.2 C. The requirements of this British Standard align with those of two draft International Standards for thermometers, ISO/DIS 3862) and ISO/DP 61523) insofar as they were known at the time of prepara
13、tion. The International Standards were in course of preparation by Sub-committee 3, Thermometers, of ISO Technical Committee 48, Laboratory glassware and related apparatus. Appendix A lists thermometric glasses approved by the National Physical Laboratory. Information on the testing of thermometers
14、for use with alcohol hydrometers is given in Appendix B. Certification. Attention is drawn to the certification facilities described on the inside back cover of this standard. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are re
15、sponsible 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, pages i and ii, pages 1 to 6, an inside back cover and a back cover. This standard has
16、 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) Council Directive of 27 July 1976, 76/765/EEC on the approximation of the laws of the Member States relating to alcoholometers and alcohol hydromet
17、ers. 2) ISO 386 was subsequently published in 1978 without significant technical changes to the text of DIS 386. 3) In course of preparation. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5471:1977 BSI 09-19991 1 Scope This British Stan
18、dard specifies requirements for a solid-stem mercury-in-glass thermometer for use with alcohol hydrometers complying with the requirements of BS 5470. 2 References The titles of the publications referred to in this standard are given on the page 6. 3 Type, range and scale interval 3.1 The thermomete
19、r shall be of the solid-stem type. 3.2 The nominal range of the thermometer shall be from 5 C to + 40 C. 3.3 The smallest scale division shall be 0.5 C. 4 Temperature scale The thermometer shall be graduated in accordance with the Celsius scale as defined in the 1968 definition of the International
20、Practical Temperature Scale (IPTS-68) adopted by the Confrence Gnrale des Poids et Mesures, and in accordance with the International System of units (SI). 5 Immersion The thermometer shall be graduated for complete immersion, i.e. the entire thermometer being immersed in the sample. 6 Glass The ther
21、mometer shall be made of a suitable thermometric glass selected and processed so as to show the following characteristics. 6.1 The bulb shall be made of an approved thermometric glass (see Appendix A) and shall be stabilized by suitable heat treatment to ensure that the accuracy requirements of 11.1
22、 and 11.2 can be met. 6.2 The stem shall be made of a lead glass or other suitable glass with a white enamel back. 6.3 Stress in the glass of the bulb and stem shall be reduced to a level sufficient to minimize the possibility of fracture due to thermal or mechanical shock. 6.4 The legibility of the
23、 reading shall not be impaired by devitrification or clouding. 6.5 The image of the meniscus shall be distorted as little as possible by defects or impurities in the glass. 7 Liquid filling The liquid filling shall be mercury free from any contamination likely to interfere with the proper functionin
24、g of the thermometer. 8 Gas filling The space above the mercury shall be filled with a dry inert gas. 9 Construction 9.1 The thermometer shall be straight and its external cross section shall be approximately circular. 9.2 The top of the thermometer shall preferably be plain rounded, or finished wit
25、h a glass ring or button as requested by the user. 9.3 The inside of the capillary tube shall be smooth, and the cross-sectional area of the bore shall not show variations from the average greater than 10 %. 9.4 The bore of the capillary tube shall be of sufficient diameter to ensure that the thermo
26、meter complies with 10.1. 9.5 There shall be an expansion chamber at the top of the capillary tube consisting of a pear-shaped chamber with the hemisphere at the top. The volume above the scale shall be such that the thermometer will withstand exposure to a temperature of 80 C without damage. Licens
27、ed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 5471:1977 2 BSI 09-1999 9.6 Dimensions of the thermometer shall be as given in Table 1. Table 1 Dimensions for thermometer for use with alcohol hydrometers 10 Marking 10.1 General. The thermometer
28、 shall be such that its indication can easily be read through the wall of a glass jar containing the sample. NOTEThe bore, scale lines, and figuring often have to be viewed under the poor lighting conditions commonly encountered in the field use of alcohol hydrometers. 10.2 Scale lines and figuring
29、10.2.1 The pattern of graduation shall be as follows. a) Every tenth scale line shall be a long line. b) There shall be four medium lines equally spaced between two consecutive long lines. c) There shall be one short line between two consecutive medium lines or between consecutive medium and long li
30、nes. 10.2.2 Every tenth scale line shall be fully figured. 10.2.3 The scale lines shall be clearly etched or otherwise durably marked and of a uniform thickness, which shall not be less than 0.12 mm nor exceed 0.20 mm. The lines shall be at right angles to the axis of the thermometer. 10.2.4 When th
31、e thermometer is held in a vertical position and viewed from the front, the left hand ends of all the scale lines shall lie on an imaginary vertical line. When the thermometer is viewed in such a position that the right-hand end of the shortest scale lines align with the left-hand side of the bore,
32、the medium and long lines shall extend across the bore towards the right. The figures shall be placed slightly to the right of the line in such a way that an extension of the line to which they refer would bisect them. The figures shall be upright when the thermometer is held vertically and shall be
33、 so chosen to ensure that the thermometer complies with 10.1. When the mercury column is viewed in this position at least the right-hand ends of the shortest scale lines and the figures shall be in full view. The minimum length of the shortest scale lines shall be 1.5 mm; the length of the medium sc
34、ale lines shall be nominally 1.5 times the length of the short lines, and the length of the long scale lines shall be nominally 2.5 times the length of the short scale lines. The scale lines and figures shall be so positioned that the enamel backing in the stem provides a background to the mercury c
35、olumn when it is seen just beyond the right-hand end of the short scale lines. 10.2.5 Each end of the scale shall be extended by 2 or 4 divisions beyond the nominal scale limits. 10.3 Pigment filling. The pigment filling in the etched scale lines, figuring and inscriptions shall be black and shall w
36、ithstand immersion in all mixtures of ethanol and water for at least 24 h. Dimension mm Total lengthmax. min. 250 245 Distance from top of bulb (shoulder) to lower nominal limit of scalemin.20 Length of scale (between nominal limits)min.130 Diameter of stem5.5 to 8.0 External diameter of bulbmin. ma
37、x. 5 not greater than that of stem Length of bulb to shouldermin.15 Distance from top of bulb funnel to lowest scale linemin.13 Distance from highest scale line to bottom of expansion chambermin.10 Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c)
38、 BSI BS 5471:1977 BSI 09-19993 11 Accuracy 11.1 Instrument error. The maximum permissible instrument error shall be 0.2 C when the thermometer is vertical and completely immersed in the sample. 11.2 Interval error. The maximum permissible difference between the errors at any two points which are 50
39、divisions apart shall not be more than 0.4 C. 12 Inscriptions The following inscriptions shall be durably and legibly marked on the thermometer. a) Temperature scale indication. The official symbol: “C”. An abbreviation of the name Celsius, e.g. “C” is also permitted. b) Immersion. “Complete” or sui
40、table abbreviation. c) Gas filling, e.g. “Nitrogen filled”, or suitable abbreviation. d) Bulb glass. The glass from which the bulb is made should preferably be identified by means of a coloured stripe or stripes, or by an inscription on the thermometer (see Appendix A). e) Manufacturers identificati
41、on number. The last two digits of the number shall indicate the year of manufacture. f) Makers name or readily identifiable mark. g) The number of this British Standard, i.e. BS 5471. h) The designation, i.e. AH/0.5/ 5/+ 40. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2
42、006, Uncontrolled Copy, (c) BSI BS 5471:1977 4 BSI 09-1999 Appendix A List of approved NPL glasses Table 2 Thermometric glasses approved by the National Physical Laboratory (1977) Appendix B Testing of British Standard thermometers The British Standards Institution at its Hemel Hempstead Centre is p
43、repared to examine thermometers for compliance with the requirements of this British Standard. Satisfactory thermometers are marked with the letters BST and the year of test. Testing arrangements and particulars of fees can be obtained on application to the Director, British Standards Institution, M
44、aylands Avenue, Hemel Hempstead, Herts HP2 4SQ. It is desirable that thermometers be retested at intervals not exceeding five years, or more frequently if determinations at a reference point indicate that retest is required. A change of one or two divisions does not necessarily indicate the need for
45、 a complete retest as this may be due to a normal change in the volume of the bulb and may be allowed for by applying a correction, equal to the zero change, throughout the scale. GlassIdentification stripe(s) or approved abbreviation Normal maximum working temperature C Normal glass, made by Whitef
46、riars Glass LimitedSingle blue stripe350 Normal glass, Dial, made by Plowden and Thompson LimitedDouble blue stripe350 Normal glass, Schott-N 16, made by Jenaer Glaswerk Schott and Genossen, MainzSingle red stripe350 Normal glass, 7560, made by Corning Glass CompanyCN350 Corning borosilicate glass,
47、made by Corning Glass CompanyCB450 Thermometric glass, Schott-2954, made by Jenaer Glaswerk Schott and Genossen, MainzSingle black stripe460 Borosilicate glass, made by Whitefriars Glass LimitedSingle white stripe460 Corning glass, 1720, made by Corning Glass CompanyC 1720600 Schott-Supermax R 8409,
48、 made by Jenaer Glaswerk Schott and Genossen, MainzSPX 8409600 NOTEThe maximum temperatures given in the last column of the table are a guide to normal practice. The performance of a thermometer depends greatly on the stabilizing heat treatment which it has been given during manufacture, and a well-
49、made thermometer of “normal glass” may be quite satisfactory for many purposes at temperatures as high as 400 C. On the other hand, for the best accuracy it may be preferred to use one of the borosilicate glasses for temperatures lower than 350 C. In general, the lower the maximum temperature of use in relation to the approved temperature of the glass, the better will be the “stability of zero” of the thermometer. Licensed Copy: sheffieldun sheffieldun, na, Fri Dec 01 14:19:35 GMT+00:00 2006, Uncontrolled Copy, (c) BSI 5blank Licensed Copy: sheffi
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