1、BRITISH STANDARD BS 3509:1962 Specification for Spirit level vialsBS3509:1962 This British Standard, having been approved by the InstrumentIndustry Standards Committee and endorsed by the Chairman of the Engineering Divisional Council, was publishedunder the authority ofthe General Council on 1June1
2、962 BSI 08-1999 The following BSI references relate to the work on this standard: Committee references INE/9 and INE/9/2 Draft for comment AA(INE) 9011 ISBN 0 580 35253 6 Co-operating organizations The Instrument Industry Standards Committee, under whose supervision this British Standard was prepare
3、d, consists of representatives from the following Government departments and scientific and industrial organizations: Association of Scientific Workers British Clock and Watch Manufacturers Association British Electrical and Allied Industries Research Association British Electrical and Allied Manufa
4、cturers Association British Industrial Measuring and Control Apparatus Manufacturers Association British Iron and Steel Federation British Nautical Instrument Trade Association British Railways, The British Transport Commission British Scientific Instrument Research Association* Council of British M
5、anufacturers of Petroleum Equipment Electricity Council, the Generating Board and the Area Boards in England and Wales Electronic Engineering Association Engineering Equipment Users Association Gauge and Tool Makers Association Institute of Physics and The Physical Society* Institution of Chemical E
6、ngineers Institution of Electrical Engineers Institution of Heating and Ventilating Engineers Institution of Mechanical Engineers Iron and Steel Institute Meteorological Office Ministry of Health Ministry of Housing and Local Government National Coal Board National Physical Laboratory (D.S.I.R.)* Oi
7、l Companies Materials Association Scientific Instrument Manufacturers Association* Society of Instrument Technology* War Office* Water-tube Boilermakers Association The Government departments and scientific and industrial organizations marked with an asterisk in the above list, together with the fol
8、lowing, were directly represented on the committee entrusted with the preparation of this standard: Admiralty British Photographic Manufacturers Association Ltd. Federation of Manufacturing Opticians Royal Microscopical Society Manufacturers of Spirit Level Vials Amendments issued since publication
9、Amd. No. Date CommentsBS3509:1962 BSI 08-1999 i Contents Page Co-operating organizations Inside front cover Foreword ii Section 1. General 1 Scope 1 2 Definitions 1 3 Materials 1 Section 2. Graduation marks 4 Straight cylindrical vials 2 5 Bent cylindrical vials 3 6 Circular vials 3 Section 3. Dimen
10、sions 7 Straight cylindrical vials 4 8 Bent cylindrical vials 5 9 Circular vials 6 Section 4. Performance 10 Straight cylindrical vials 7 11 Bent cylindrical vials 9 12 Circular vials 9 Appendix A Recommended method of testing 10 Appendix B Recommendations for standard mounts 12 Appendix C Metric-in
11、ch conversions 16 Figure 1 Forms of vial graduation marks 2 Figure 2 Dimensional nomenclature for straight vials 4 Figure 3 Tolerance zone for pipped end(s) 5 Figure 4 Standard dimensions for circular vials 6 Figure 5 Diagram illustrating basic principles of vial testing equipment 11 Figure 6 Recomm
12、ended form of mount type A for cylindrical vials 13 Figure 7 Recommended form of mount type B for cylindrical vials 14 Figure 8 Recommended form of mount type C for cylindrical vials 14 Figure 9 Recommended forms of mount for circular vials 15 Table 1 Vial dimensions 4 Table 2 Sensitivity values of
13、standard straight cylindrical vials 7 Table 3 Performance tolerances for cylindrical vials 8 Table 4 Approximate settling times for spirit level vials 9BS3509:1962 ii BSI 08-1999 Foreword This standard makes reference to the following British Standard: BS 958, Precision levels for engineering worksh
14、ops. This British Standard has been prepared under the authority of the Instrument Industry Standards Committee to introduce simplification into the manufacture of spirit levels by reducing their diversity, to guide interested users in their requirements and to permit the greatest possible degree of
15、 interchangeability. The only other standard in which reference is made to spirit levels is BS958, “Precision levels for engineering workshops”, and this has been taken into account in the preparation of the present standard. The scope of this standard, BS3509, however, includes spirit levels used o
16、n surveying instruments, on general levelling instruments and in inspection techniques. Spirit levels have hitherto been specifically designed to suit the instruments in which they are fitted and used, consequently, although the sensitivity requirement of any particular vial has been directly relate
17、d to the accuracy and function of the instrument, its size has been governed by the space available for its fitting in each individual case. This standard will lead the designer or user to choose a vial of the optimum size for a given accuracy. In this connection it should be pointed out that there
18、is little to be gained in accuracy by increasing the sensitivity of a vial beyond the values given for a particular size. NOTEThe values given herein, whether metric or British units, are to be regarded as standard;Appendix C contains conversions for British and metric units. These conversions are a
19、pproximate. More accurate conversions should be based on BS350, “Conversion factors and tables”. 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 doe
20、s not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to17 and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in t
21、he amendment table on the inside front cover.BS3509:1962 BSI 08-1999 1 Section 1. General 1 Scope This British Standard deals in detail with the various sizes and performance requirements for both precise and coarse spirit level vials. Ranges of parameters of spirit level vials for use in precision
22、surveying, inspection and general levelling instruments are related to the sensitivity, and preferred sets of parameters for given sensitivities are indicated. InAppendix A is given a recommended method of testing vials and recommendations are made inAppendix B for preferred forms of mounting. 2 Def
23、initions For the purposes of this British Standard, the following definitions apply: 2.1 spirit level vial a glass vessel suitably processed, partially filled with a liquid-of low freezing point and viscosity, and completely sealed 2.2 straight cylindrical vial a vial made from nominally straight gl
24、ass tube which has been fully barrel ground or partially ground internally to a required radius of curvature longitudinally 2.3 bent cylindrical vial a vial made by bending the glass tube to a required radius of curvature longitudinally 2.4 circular vial a vial possessing a spherical functional surf
25、ace whereby inclinations in all directions can be detected in contradistinction to vials in2.2 and2.3 above which are only required to be sensitive to tilts along their longitudinal axis 2.5 bubble the small space created inside the sealed glass tube due to partial filling. This is occasionally refe
26、rred to as the air-space or air-bell NOTEIt is customary to refer to spirit level vials themselves as “bubbles”; to avoid confusion of terms this mode of reference is not used in this specification. 2.6 sensitivity that angle of tilt which causes the bubble in the vial to move through one scale divi
27、sion 2.7 range the total angle of tilt throughout which a vial can be used 2.8 roll the rotation of a straight cylindrical vial about an axis parallel to the axis of the internally ground surface 2.9 roll error the longitudinal movement of the bubble (due to imperfections in the ground surface of th
28、e vial) when rolled through a specified amount about the above axis in definition2.8 2.10 repeatability the measure of the ability of the bubble to return to its original position when the vial has been disturbed and subsequently restored to its original attitude 2.11 settling time the time taken fo
29、r a bubble to return to within one tenth of a scale division of its steady position when the vial has been tilted through a specified angle 3 Materials a) Glass. The glass shall be well annealed and, over the viewing portion transparent, free from stri, flaws and other defects. The composition of th
30、e glass shall be such that it is not reacted upon by the filling liquid or any colouring agent used. b) Filling liquid. The liquid shall be clear, free from impurities and solid particles and shall be chemically inert to the glass and, if present, the colouring material. It shall not cloud or decomp
31、ose on prolonged exposure to sunlight and shall remain fluid at a temperature of 40 C. The filling liquid should not normally be coloured. Fluorescent materials such as eosin (for orange) and fluorescein in (for green) may be used if specified by the purchaser.BS3509:1962 2 BSI 08-1999 Section 2. Gr
32、aduation marks 4 Straight cylindrical vials a) Graduation marks shall be centrally located along the parallel portion of the vial to within 1mm. NOTE 1Where a vial with one end square and the other end pipped is used, the graduation marks will, by conforming to this requirement, appear “off centre”
33、in relation to the overall vial length. This feature can be corrected during mounting so that the graduation marks appear central over the viewing portion. NOTE 2The top of the vial will usually be graduated to assist in bringing the bubble into the centre of its run and to indicate the movement of
34、the bubble for a specified tilt. An exception to this is when a special coincidence prism reading arrangement is added to the bubble assembly. b) When a vial is to be graduated, one of the forms shown inFigure 1 shall be adopted. c) In all cases, save Type I and Type II vials (seeTable 1), the nomin
35、al distance between two consecutive graduation marks shall be2mm, whilst the quoted sensitivity for a vial graduated with two graduation marks only shall be for a2mm run. For Type I and Type II vials the scale interval shall be2.5mm. (The scale spacing between graduation marks may vary by5percent fr
36、om their average, the average interval being within 10percent of the nominal.) d) The two major graduation marks of any scale shall be dearly designated by their increased length and/or their being terminated by dots. They shall be the same length and shall indicate the position of the bubble at the
37、 centre of its run. These major graduation marks shall be separated by a distance equal to the length of the bubble plus0.5mm to3mm at20 C. e) All graduation marks shall be straight with sharp edges, at right angles to the longitudinal axis of the vial and of a uniform thickness equal to0.25mm 20per
38、cent. An imaginary centre line drawn through them shall be parallel to the same longitudinal axis. f) When the scale is of the continuous type, every fifth line shall be extended for ease of reading. All intermediate lines shall be of the same length. g) As viewed in plan, the length of the shorter
39、lines shall approximate to one third the diameter of the vial and the longer graduation marks to one half the vial diameter. All graduation marks shall be permanent and should normally be black. Other colours of graduation mark shall be subject to agreement between the user and manufacturer. h) Vial
40、s with sensitivity values of1minute or less shall have the nominal sensitivity marked on the tube. It is usual to append the scale interval itself to this figure, viz:20seconds of arc/2mm,10seconds of arc/0.1in, etc. (or20second/2mm,10seconds/0.1in, etc.). Alternatively this angle can be expressed a
41、s the equivalent length of are at the end of a10in radius or base length. The connection between these two methods of expressing sensitivity is: 1 second of arcN 0.0000485 inches in10inches 0.00005inches in10inches Figure 1 Forms of vial graduation marksBS3509:1962 BSI 08-1999 3 5 Bent cylindrical v
42、ials a) Graduation marks shall be restricted to one line at each bubble end as shown inFigure 1c. b) Other requirements for bent cylindrical vials shall be as given in the appropriate sub-clause of Clause4 suitably applied where relevant. 6 Circular vials a) The circular graduation mark shall be lar
43、ger than the bubble or air-space diameter by1 to2mm at20 C, whilst the bubble diameter at this temperature shall be nominally one third of the vial diameter. b) The circular graduation mark may be etched, printed or formed on either the outer or inner side of the vial. The graduation mark when insid
44、e must not interfere with the movement of the bubble. The thickness of the graduation mark shall be uniform and equal to0.25mm 20percent.BS3509:1962 4 BSI 08-1999 Section 3. Dimensions 7 Straight cylindrical vials a) The standard dimensions of straight cylindrical vials shall be as specified inTable
45、 1. Table 1 Vial dimensions (SeeFigure 2) Dimension Type I Type II Type III Type IV Type V Type VI mm mm mm mm mm mm A (min.) B (max.) C (max.) D E F H 100 10 120 1315 1.25 3350 2.5 75 9 93 1214 1.25 2537 2.5 60 8 76 1113 0.75 2030 2 45 7 59 1012 0.75 1522 2 30 6 42 810 0.75 1015 2 20 5 30 68 0.75 7
46、10 2 Figure 2 Dimensional nomenclature for straight vials (seeTable 1)BS3509:1962 BSI 08-1999 5 NOTE 1Variation in bubble length with temperature. Since the length of the bubble varies with temperature, when this variation is required to be as small as practicable, Type III or IV vials can be produc
47、ed by the manufacturer to suit more stringent requirements than those specified in Sub-clause11 d)i). To suit a temperature outside the range 5 C to +50 C, the bubble/scale relationship can be adjusted during manufacture when so specified. NOTE 2Reversion vials. In several instruments, notably preci
48、sion survey levels, it is imperative that the vial be usable in either of two positions in which the second is obtained by rotating the vial180 about an axis parallel to its longitudinal axis. Choice of any such vial would usually be made from Types I or II. 8 Bent Cylindrical vials There shall be o
49、ne standard sized bent cylindrical vial conforming to the Type VI vial listed inTable 1. A is the length of the external parallel portion of the vial. The values given inTable 1 are minimum lengths for each type. No maximum lengths are given since these are restricted by the maximum value stated for the overall length C and the allowance B for sealing the ends. B is the length of the vial ending measured from the end of the parallel portion to the pip. Maximum values only are given. Both ends of the vial may
