1、BRITISH STANDARD CONFIRMED AUGUST 1990 BS 3403:1972 Specification for Indicating tachometer and speedometer systems for industrial, railway and marine useBS3403:1972 This British Standard, having beenapproved by the InstrumentIndustry StandardsCommittee, waspublished under the authority of the Execu
2、tive Board on 7 April 1972 BSI 09-1999 First published July 1961 First revision April 1972 The following BSI references relate to the work on this standard: Committee reference INE/8/2 INE/8 Draft for comment 69/19989 ISBN 580 07400 5 Co-operating organizations The Instrument Industry Standards Comm
3、ittee, under whose supervision this British Standard was prepared, consists of representatives from the following Government departments and scientific and industrial organizations: British Calibration Service British Electrical and Allied Manufacturers Association* British Industrial Measuring and
4、Control Apparatus Manufacturers Association British Mechanical Engineering Confederation British Nautical Instrument Trade Association British Railways Board* British Steel Industry Department of the Environment Electrical Research Association Electricity Council, the Generating Board and the Area B
5、oards in England and Wales Electronic Engineering Association Engineering Equipment Users Association Gauge and Tool Makers Association Hevac Association Institute of Measurement and Control Institution of Chemical Engineers Institution of Electrical Engineers Institution of Heating and Ventilating
6、Engineers Institution of Mechanical Engineers* Institution of Production Engineers Meteorological Office Ministry of Defence, Air Force Department Ministry of Defence, Army Department* Ministry of Defence, Navy Department National Coal Board National Physical Laboratory Oil Companies Materials Assoc
7、iation Scientific Instrument Manufacturers Association SIRA Institute* Water-tube Boilermakers Association The Government department and scientific and industrial organizations marked with an asterisk in the above list, together with the following, were directly represented on the committee entruste
8、d with the preparation of this British Standard: British Internal Combustion Engine Manufacturers Association London Transport Executive Ministry of Defence, (Navy) Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No. Date CommentsBS3403:1972 BSI 09-1999 i
9、Contents Page Co-operating organizations Inside front cover Foreword ii 1 General 1 1.1 Scope 1 1.2 Accuracy classes 1 1.3 Definitions 1 2 Design and construction 2 2.1 General 2 2.2 Drives and electrical connections 2 2.3 Environment 2 2.4 Dial diameters 3 2.5 Scale ranges, scales and indexes 3 2.6
10、 Direction of deflection 3 2.7 Zero adjustment 3 2.8 Normal position of use and mounting 3 3 Performance requirements and tests 3 3.1 Reference conditions 3 3.2 Effective range 3 3.3 Routine test requirements 4 3.4 Type test requirements 5 4 Test certificates and marking 7 4.1 Test certificates 7 4.
11、2 Identification marking 7 4.3 Marking of terminals 7 4.4 Installation instructions 7 Appendix A Notes on testing of tachometry systems for accuracy 9 Figure 1 Relationship between amplitude and frequency 8BS3403:1972 ii BSI 09-1999 Foreword This standard makes reference to the following British Sta
12、ndards: BS 229, Flameproof enclosure of electrical apparatus. BS 1259, Intrinsically safe electrical apparatus for use in explosive atmospheres. BS 1597, Radio-interference suppression on marine installations. BS 1991, Letter symbols, signs and abbreviations Part 3: Fluid mechanics. BS 2011, Methods
13、 for the environmental testing of electronic components and electronic equipment Part 2: Tests Part 2Da: Damp heat, cyclic Part2Ka:Salt mist. BS 3693, Recommendations for the design of scales and indexes. BS 3807, Method for the type testing of enclosures for electrical apparatus for use in onerus d
14、ust conditions. CP 1006, General aspects of radio interference suppression. This British Standard has been prepared under the authority of the Instrument Industry Standards Committee. This second edition of the standard which originally dealt with indicating tachometers for general industrial use ha
15、s been revised in order to cater for tachometer and speedometer systems for industrial, railway and marine applications. This standard is not intended to cover digital tachometers, nor does it cover aircraft applications or speedometers for road vehicles. Speedometers for road vehicles are covered i
16、n BS 3190. 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 pages This document
17、 comprises a front cover, an inside front cover, pages i and ii, pages1to10, 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.BS3403:1972 BSI 09
18、-1999 1 1 General 1.1 Scope This British Standard specifies requirements for indicating tachometer and speedometer systems with or without revolution counters for industrial, railway and marine application. NOTEThe titles of the British Standards referred to in this standard are listed on page ii 1.
19、2 Accuracy classes The three classes of accuracy specified in this standard are as follows: Class index 0.75. System having a nominal accuracy of 0.75% of maximum scale value (see 3.3.3). Class index 1.5. System designed for general purposes, having a nominal accuracy of 1.5 % of maximum scale value
20、 (see 3.3.3). Class index 3.0. System designed for general purposes, having a nominal accuracy of 3 % of maximum scale value (see 3.3.3). All the requirements of this standard apply to Class0.75, Class 1.5 and Class 3.0 instruments, except where a distinction between these three classes is made. 1.3
21、 Definitions For the purposes of this British Standard, the following definitions apply: 1.3.1 tachometer system a means of measuring the rate of revolution of a rotating body. It may also, but not necessarily, detect the direction of rotation 1.3.2 speedometer system a device for the measurement of
22、 distance travelled per unit time 1.3.3 mechanical tachometer a tachometer in which the linkage between the rotating body and the measuring device is wholly mechanical 1.3.4 electrical/electronic tachometer a tachometer in which the means of detection, transmission and measurement are partly electri
23、cal 1.3.5 magnetic tachometer a mechanical or electrical tachometer in which the indicating component includes a driving link effected by interaction between a relatively rotating magnetic system and an induction cup or disc 1.3.6 electrical/electronic tachometer transmitter a device which provides
24、electrical signals from which the rate of revolution can be measured 1.3.7 electrical/electronic tachometer indicator a device which accepts signals from the electrical tachometer transmitter with or without intermediate conversion and indicates visually the rate of revolution 1.3.8 index the pointe
25、r or other means by which the measured quantity is indicated relative to the scale 1.3.9 scale the array of marks together with any associated figuring from which the indicated quantity may be read 1.3.10 accuracy the accuracy of a measuring instrument or of an accessory is defined by the limits of
26、intrinsic error and the limits of variations due to influence quantities 1.3.11 accuracy class a class of measuring instruments or accessories, the accuracy of all of which can be designated by the same number, if they comply with all the clauses of this standard 1.3.12 class index the number which
27、designates the accuracy class NOTE 1The class index is applicable to the variation as well as to the intrinsic error. NOTE 2Multi-range instruments may have more than one class index. 1.3.13 maximum scale value the greatest value of the measured quantity which the scale is graduated to indicate NOTE
28、 1In multi-range instruments this definition is to be read as applying to the particular range which the instrument is set up to measure. NOTE 2In centre-zero or offset zero type instruments the maximum scale value is to be taken as the sum of the two end scale values.BS3403:1972 2 BSI 09-1999 1.3.1
29、4 minimum scale value the smallest value of the measured quantity which the scale is graduated to indicate NOTEIn multi-range instruments this definition is to be read as applying to the particular range which the instrument is set up to measure. 1.3.15 scale range the number of units indicated on t
30、he scale between the two scale-end marks, with the exception that in suppressed zero instruments, the scale range is from the minimum to the maximum scale value 1.3.16 effective range that portion of the scale over which the instrument complies with the specified limits of error 1.3.17 revolution co
31、unter a device which counts and displays revolutions (or derived units) without respect to time. It may or may not be an integral part of the indicator 2 Design and construction 2.1 General The construction shall be mechanically sound, and such as to assure permanence in all mechanical, electrical,
32、electronic or magnetic adjustments when used in accordance with the manufacturers recommendations. Mechanical and magnetic types shall be self-contained except for drive details. Electrical tachometers shall consist essentially of two separate units, namely the transmitter and the indicator. Electro
33、nic types shall consist essentially of three units, viz. the transmitter, electronic conversion unit and indicator. Any of these units may be combined. Electrical or electronic units shall be connected together by electrical cables, either with or without a separate source of electric supply. Where
34、required, protection against reversal of polarity of a d.c. auxiliary supply shall be provided. Where revolution counters are incorporated in the indicator, it is recommended that the figures should be outside the swept area of the index. 2.2 Drives and electrical connections The coupling shall not
35、alter the mean angular velocity condition of drive. The choice of drive and method of attachment together with any electrical connections shall be the subject of agreement between the purchaser and the manufacturer. Where instruments are mechanically coupled, the drives shall be capable of accommoda
36、ting a reasonable amount of angular, parallel or end float displacement between the prime mover and the instrument system so that the accuracy requirements of the tachometer system are maintained. Suitable forms of mechanical drive include flexible couplings, spring couplings, pin and slot couplings
37、, dog couplings, flexible cable drive, chain and sprocket, toothed belt. The magnetic or electronic pulse type of tachometer system may be driven as above or it may be directly applied at the point of sensing. 2.2.1 Sealing of drive. It is the responsibility of the user and the manufacturer jointly
38、to prevent the transfer of lubricant to the drive where this is detrimental to satisfactory operation. Due account should also be taken of any relevant environmental conditions. 2.3 Environment 2.3.1 The indicator, transmitter and ancillary apparatus shall be contained in suitable enclosures to affo
39、rd adequate protection and to ensure permanence of the accuracy of the indications. 2.3.2 Vibration resistance. The tachometry system shall be designed to withstand without damage the vibration test specified in 3.4.8, except that the indicator, if not normally subjected to vibration in service, may
40、 be excluded by agreement between the purchaser and the manufacturer. 2.3.3 Shock resistance. The tachometry system shall be designed to withstand the shock test specified in 3.4.9. 2.3.4 Variation in indication due to mounting on ferrous supports. Unless otherwise agreed, the variation in indicatio
41、n of a tachometer (or of the receiver for a tachometer transmitter), when mounted on a ferrous support not less than 3 mm thick, shall not differ from that obtained free in air by more than the figure quoted in 3.4.6. 2.3.4.1 Variation in output of a generator/transmitter due to mounting, on ferrous
42、 supports. Unless otherwise agreed, the variation in output of a tachometer generator or transmitter, when mounted on a ferrous support not less than6mm thick, shall not differ from that obtained free in air by more than the figure quoted in 3.4.6.BS3403:1972 BSI 09-1999 3 2.3.5 Effect of transients
43、 (spikes and surges) in electronic systems. In general transients will be found to occur and both manufacturer and user should consult each other regarding suppression/immunity. 2.3.5.1 Where commutation or switching is liable to cause radio interference, care shall be taken to minimize such interfe
44、rence, as recommended in CP1006 and BS 1597. 2.3.6 Intrinsic safety. An intrinsically safe system shall satisfy the requirements of BS 1259. 2.3.7 Flameproofing. A flameproof enclosure shall satisfy the requirements of BS 229. 2.3.8 Weatherproofing. A weatherproof enclosure shall be so constructed o
45、r protected that exposure to the weather or splashings of water will not impair the operation of the instrument (foratest,see3.4.10). 2.3.9 Watertightness. A watertight enclosure shall satisfy the watertightness tests specified in 3.4.11. 2.3.10 Dustproofing. A dustproof enclosure shall satisfy the
46、requirements of BS 3807. 2.3.11 Saltspray. A saltspray-proof system shall satisfy the requirements of BS 2011-2Ka. 2.3.12 Tropical use. A tachometer system required for use in particularly severe tropical conditions e.g.high relative humidity, extremes of temperature, shall meet the requirements of
47、BS2011-2Da or such other appropriate Part of BS2011 as might be agreed between the purchaser and the manufacturer. 2.4 Dial diameters The recommended nominal visible dial diameters are 75, 100, 150, 200 and 300 mm. 2.5 Scale ranges, scales and indexes Scale ranges, scales and indexes should be in ac
48、cordance with BS 3693. 2.6 Direction of deflection Unless otherwise specified by the purchaser, the following requirements apply: 1) The direction of deflection of the index of a tachometer for an increasing quantity shall be clockwise for a substantially circular scale of more than 180 degrees, def
49、lection from left to right for a substantially horizontal scale, and upwards for a substantially vertical scale. 2) In other cases the direction of deflection shall be as far as possible upwards for an increasing quantity. 3) In a centre or offset zero indicators deflection to the right or clockwise shall be “forward”, and deflection to the left or anticlockwise shall be “reverse”. 2.7 Zero adjustment Tachometer indicators may be fitted with a suitable device for adjusting the pointer to zero or other setting mark. Where such a device is fitted, there shall
