1、BRITISH STANDARD BS3625:1963 Specification for Eyepiece and screen graticules For the determination of particle size of powdersBS3625:1963 This British Standard, having been approved by the Chemical Engineering Industry Standards Committee and endorsed by the Chairman of the Engineering Divisional C
2、ouncil, was publishedunder the authority ofthe General Council on 4November1963 BSI10-1999 The following BSI references relate to the work on this standard: Committee referenceCHE/50, CHE/50/1 Draft for commentCZ(CHE)/8773 ISBN 0 580 03794 0 Co-operating organizations The Chemical Engineering Indust
3、ry Standards Committee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: The scientific and industrial organizations marked with an asterisk in the above list, together with
4、the following, were directly represented on the committee entrusted with the preparation of this British Standard: Association of British Chemical Glass Manufacturers Federation Manufacturers* Institute of Petroleum Association of Consulting Engineers Institution of Chemical Engineers* (Incorporated
5、) Institution of Gas Engineers Board of Trade Institution of Structural Engineers British Chemical Plant Manufacturers Ministry of Transport Association* Society or Chemical Industry (Chemical Coke Oven Managers Association Engineering Group)* Engineering Equipment Users Association UnitedKingdom At
6、omic Energy Authority Gas Council Aluminium Federation Institution of Mining and Metallurgy Borough Polytechnic Ministry of Aviation British Cast Iron Research Association Ministry of Power British Coal Utilization Research Association National Physical Laboratory (D.S.I.R.) British Colour Makers As
7、sociation Oil and Colour Chemists Association British Diamond Die Federation Permanent Magnet Association British Electrical and Allied Manufacturers Pharmaceutical Society of Great Britain Association Radio and Electronic Component British Hard Metal Association Manufacturers Federation British Pha
8、rmacopoeia Commission Research Association of British paint, Colour Cement and Concrete Association and Varnish Manufacturers Cement Makers Federation Society of Cosmetic Chemists of Great Britain D.S.I.R. Road Research Laboratory Toilet Preparations Federation Ltd. D.S.I.R. Warren Spring Laboratory
9、 University of London Imperial College of Science and Technology War Office Incorporated National Association of British Zinc Pigment Development Association and Irish Millers Ltd. Individual firms Institute of Physics and The Physical Society Amendments issued since publication Amd. No. Date Commen
10、tsBS3625:1963 BSI 10-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii 1 Scope 1 2 Construction 1 3 Pattern of circles and rulings 1 4 Relative dimensions of grid and circles 3 5 Dimensions of grid 3 6 Marking 3 Table Relative dimensions of standard graticule 3BS3625:196
11、3 ii BSI 10-1999 Foreword This Standard makes reference to the following British Standard: BS3406, Methods for the determination of particle size of powders Part4:optical microscope method. The present publication is a specification for the standard graticule required for the method of BS3406-4. BS3
12、406-4 1)is one of a series of standards which describes methods of determining the size distribution of particles in those fractions of powders which pass through a75micron British Standard test sieve. 2)A representative sample of the powder to be sized is dispersed and placed on a glass slide and t
13、he particles are viewed through a microscope by means of transmitted light. The areas of the magnified images of the particles are compared with the areas of reference circles of known sizes inscribed on a graticule and simultaneously visible. The relative numbers of particles in each of a series of
14、 size classes are determined. 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 does not of itself confer immunity from legal obligations. Summary of
15、pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to3 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) BS3406, “Methods fo
16、r the determination of particle size of powders”. Part 4, “Optical microscope methods.” 2) BS410, “Test sieves.”BS3625:1963 BSI 10-1999 1 1 Scope This British Standard specifies requirements for the design and construction of eyepiece and screen graticules for particle size analysis by the optical m
17、icroscope method as described in BS3406-4 1) . 2 Construction The graticule shall consist of black rulings to the pattern and dimensions specified below. In the case of screen graticules the background to the rulings shall form a diffusing screen. 3 Pattern of circles and rulings The graticule shall
18、 be made to the pattern shown in the Figure which comprises: a rectangular grid subdivided as shown two calibration marks drawn across the longer axis of the grid and ringed at their intersections with that axisBS3625:1963 2 BSI 10-1999 a set of seven open circles a set of seven solid circles the nu
19、mbers1 to7 adjacent to the circles the words GRID LENGTH followed by the actual length in millimetres of the longer dimension of the rectangular grid the makers name and the number of this Standard, BS3625 (see Clause6). The circles and rulings shall be clear and legible on an eyepiece graticule vie
20、wed with a 10 magnifying lens, or on a screen graticule viewed by the unaided eye. The area containing the circles and rulings shall be free of blemishes which could interfere with the use of the graticule.BS3625:1963 BSI 10-1999 3 4 Relative dimensions of grid and circles The relative dimensions of
21、 the grid and circles are specified in the Table. In this table the unit of length is 1 / 64of the length of the rectangular grid. Tolerances on the relative dimensions are specified in the Table for a screen graticule. The same tolerances shall apply to an eyepiece graticule with the understanding
22、that none is required to take an absolute value smaller than5microns. The boundary lines of the rectangular grid shall beextended by2units to cross at each corner. The calibration marks on the longer axis of the grid shallbe6units in length and shall be symmetrically placed. The sub-dividing lines o
23、f the grid shall form in the pattern shown the following areas: two each 1 / 4 , 1 / 8 , 1 / 16and 1 / 32and four each 1 / 64of the total area of the grid. The length and breadth of the grid (and of the sub-divisions) and the distance between the calibration marks shall be measured between the centr
24、es of the ruling lines. The diameters of the open circles shall be measured between the outside edges of the ruling lines. The width of the ruling lines shall be the same within 20percent in all parts of the graticule and shall not exceed 1 / 7unit (that is, 1 / 448 th of the grid length). 5 Dimensi
25、ons of grid The actual length of the longer dimension of the grid shall lie within 2percent of the value marked on the graticule. The length of the grid of a screen graticule shall not be less than96mm. Table Relative dimensions of standard graticule 6 Marking Graticules manufactured in compliance w
26、ith this British Standard shall be marked with the following particulars: The name, trade mark or other means of identification of the manufacturer. The number of this British Standard, i.e.BS3625. NOTEThe mark BS3625:1963 on the product is a claim by the manufacturer that it complies with the requi
27、rements of the standard. The British Standards Institution is the owner of the registered certification trade mark shown below. This mark can be used only by manufacturers licensed under the certification mark scheme operated by the BSI. The presence of this mark on a product is an assurance that th
28、e goods have been produced to comply with the requirements of the British Standard under a system of supervision, control and testing operated during manufacture and including periodical inspections at the manufacturers works in accordance with the certification mark scheme of the BSI. Further parti
29、culars of the terms of licence may be obtained from the Director, British Standards Institution, Numerical value and toleranceunits a Grid length Grid breadth Distance between calibration marks Diameter of circle 1 2 3 4 5 6 7 64 45.3 0.25 60.4 0.25 1.00 0.02 1.41 0.03 2.00 0.04 2.83 0.06 4.00 0.08
30、5.66 0.10 8.00 0.12 a The unit is 1 / 64 th of the grid length.BS3625:1963 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 the international
31、level. It is incorporated by Royal Charter. Revisions BritishStandards are updated by amendment or revision. Users of BritishStandards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. We would be
32、grateful if anyone finding an inaccuracy or ambiguity while using this BritishStandard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel:02089969000. Fax:02089967400. BSI offers members an individual updating service
33、called PLUS which ensures that subscribers automatically receive the latest editions of standards. Buying standards Orders for all BSI, international and foreign standards publications should be addressed to Customer Services. Tel:02089969001. Fax:02089967001. In response to orders for international
34、 standards, it is BSI policy to supply the BSI implementation of those that have been published as BritishStandards, unless otherwise requested. Information on standards BSI provides a wide range of information on national, European and international standards through its Library and its Technical H
35、elp to Exporters Service. Various BSI electronic information services are also available which give details on all its products and services. Contact the Information Centre. Tel:02089967111. Fax:02089967048. Subscribing members of BSI are kept up to date with standards developments and receive subst
36、antial discounts on the purchase price of standards. For details of these and other benefits contact Membership Administration. Tel:02089967002. Fax:02089967001. Copyright Copyright subsists in all BSI publications. BSI also holds the copyright, in the UK, of the publications of the international st
37、andardization bodies. Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means electronic, photocopying, recording or otherwise without prior written permission from BSI. This does not
38、preclude the free use, in the course of implementing the standard, of necessary details such as symbols, and size, type or grade designations. If these details are to be used for any other purpose than implementation then the prior written permission of BSI must be obtained. If permission is granted, the terms may include royalty payments or a licensing agreement. Details and advice can be obtained from the Copyright Manager. Tel:02089967070.
