1、BRITISH STANDARD BS EN 472:1995 Pressure gauges Vocabulary The European Standard EN472:1994 has the status of a BritishStandardBSEN472:1995 This BritishStandard, having been prepared under the directionof the Electrotechnical Sector Board, was published underthe authority of the Standards Board and
2、comesintoeffect on 15September1995 BSI01-2000 The following BSI references relate to the work on this standard: Committee reference GEL/65 Draft for comment91/24810DC ISBN 0 580 24628 0 Committees responsible for this BritishStandard The preparation of this BritishStandard was entrusted to Technical
3、 Committee GEL/65, Measurement and control, upon which the following bodies were represented: British Coal Corporation British Gas plc British Nuclear Fuels plc Electrical Contractors Association Electricity Association Energy Industries Council GAMBICA (BEAMA Ltd.) Health and Safety Executive Insti
4、tution of Gas Engineers The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Compressed Air Society British Compressed Gases Association British Fluid Power Association British Pressure Gauge Manufacturers Association Department of Tra
5、de and Industry (National Engineering Laboratory) Amendments issued since publication Amd. No. Date CommentsBSEN472:1995 BSI 01-2000 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Text of EN472 3BSEN472:1995 ii BSI 01-2000 National foreword This BritishStan
6、dard has been prepared by Technical Committee GEL/65 and is the English language version of EN472:1994, Pressure gauges Vocabulary published by the European Committee for Standardization (CEN). No BritishStandard is superseded. A British Standard does not purport to include all the necessary provisi
7、ons 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 cover, pagesi andii, theEN title page, pa
8、ges2 to7 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.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN472 October1994 UDC681.2.084.83:001.4 Descriptors: Meas
9、uring instruments, manometers, vocabulary English version Pressure gauges Vocabulary Manomtres Vocabulaire Druckmegerte Begriffe This European Standard was approved by CEN on1994-10-19. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for givin
10、g this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versio
11、ns (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, De
12、nmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36
13、, B-1050 Brussels 1994 Copyright reserved to CEN members Ref. No. EN472:1994EEN472:1994 BSI 01-2000 2 Foreword This European Standard has been prepared by Technical Committee CEN/TC141, Pressure gauges, of which the secretariat is held by AFNOR. This European Standard shall be given the status of a
14、national standard, either by publication of an identical text or by endorsement, at the latest by April1995, and conflicting national standards shall be withdrawn at the latest by April1995. In accordance with the CEN/CENELEC Internal Regulations, the following countries are bound to implement this
15、European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Contents Page Foreword 2 0 Introduction 3 1 Scope 3 2 Definitions relating to pressure gauges 3 3 Definit
16、ions relating to pressure gauge components 3 4 Definitions relating to the characteristics 5 Index 7EN472:1994 BSI 01-2000 3 0 Introduction In the preparation of this International Standard, the following two principles have been followed as far as possible: to standardize suitable terms without per
17、petuating unsuitable terms merely because they have been used in the past; to discard any term which is used with different meanings and to replace it by a term which has an unequivocal meaning. 1 Scope This European Standard defines the fundamental and general terms to be used for pressure gauges.
18、2 Definitions relating to pressure gauges 2.1 indicating pressure gauge a measuring instrument which displays the value of the applied pressure by means of a pointer relative to a scale 2.2 indicating pressure gauges with an elastic measuring element instrument in which the mechanical measuring sequ
19、ence directly transmits the elastic deformation of the sensing element to the indicating device, consisting of a pointer and a graduated scale 2.3 pressure gauge an indicator of the applied (gauge) pressure with respect to the atmospheric pressure 2.4 vacuum gauge an indicator of the applied (gauge)
20、 vacuum with respect to the atmospheric pressure 2.5 combined pressure and vacuum gauge a combined indicator of the applied (gauge) pressure or vacuum with respect to the atmospheric pressure 2.6 absolute pressure gauge an indicator of absolute pressure, i.e.pressure relative to a complete vacuum NO
21、TEThis description therefore does not apply to pressure gauges graduated in absolute pressure units, the indications of which are influenced by variations of atmospheric pressure. 2.7 differential pressure gauge a pressure gauge used to measure the difference between two applied pressure and/or vacu
22、um values, the metallic pressure-responsive element(s) of which drive(s) one pointer 2.8 duplex pressure gauge a pressure gauge used to measure two applied pressure and/or vacuum values, by means of two separate pressure-responsive elements in one case, each of which drives its own pointer 2.9 contr
23、ol pressure gauge a pressure gauge fitted with one or more switches which open or close one or more control circuits depending on the pointer position 2.10 edgewise pressure gauge a pressure gauge with a rectangular dial for flush mounting in a panel or a control board, where the pivotal axis of the
24、 pointer lies in a plane parallel to the plane of the panel or control board 2.11 liquid filled pressure gauge a pressure gauge, the case of which is filled with a liquid 2.12 safety pattern gauge a gauge incorporating safety features and particularly suitable for use with high pressure gases and st
25、eam 3 Definitions relating to pressure gauge components 3.1 pressure-responsive element An elastic element which undergoes deformations under the effect of pressure variations. It may be a Bourdon tube, diaphragm, diaphragm capsule, bellows or other type of element. 3.1.1 bourdon tube a type of spir
26、al pressure-responsive element where a tube with a non-circular cross-section is bent into a circular or coiled shape. Under the effect of the internally applied pressure the tube tends to straighten. The deflection induced is proportional to the pressure appliedEN472:1994 4 BSI 01-2000 3.1.2 diaphr
27、agm a type of pressure-responsive element usually in the form of a concentrically corrugated membrane where the pressure applied causes the diaphragm to deflect in proportion to the pressure 3.1.3 capsule a type of pressure-responsive element comprising of two diaphragms suitably shaped and joint pr
28、essure-tight around their circumference. The pressure commonly acts on the interior of the capsule and the expansion generated thus is proportional to the pressure 3.1.4 bellows a type of pressure-responsive element in the form of a thin-walled convoluted tube. The change in its length is proportion
29、al to the pressure 3.2 movement an assembly by means of which the deformations of the pressure-responsive element are transformed and enlarged into an angular variation 3.3 pressure element assembly the assembly of all the pieces coming into contact with the fluid whose pressure is measured 3.4 conn
30、ection The part by which the pressure gauge can be coupled to the pressure tapping of the plant, pipework or equipment. 3.4.1 shank the part of the gauge that includes the screwed connection, the spanner flats, square or hexagon, the spigot, and the inlet orifice 3.4.2 screwed connection the threade
31、d portion of the shank 3.5 pointer The index, the position of which, in relation to the scale, indicates the value of the measured pressure. 3.5.1 adjustable pointer a pointer with an adjustable device for zero correction 3.5.2 maximum pointer a secondary pointer driven by the pointer which stays at
32、 the maximum value reached by the latter 3.5.3 pointer stop a screw, stud, or other projection, fitted to limit the travel of the pointer NOTEIt is not the function of a pointer stop to act as an overload stop. 3.6 adjustable mark a moving index operated from the outside and not driven by the indica
33、ting pointer, used to place a reference mark on the dial 3.7 case the casing which contains the pressure-responsive element, parts of the pressure element assembly and the movement. It may also include a safety device. The front face of the case may be circular, square or rectangular 3.8 blow-out de
34、vice A safety device incorporated in the case or back plate to permit the rapid and safe dissipation of internal pressure in the event of a leakage or burst in the pressure responsive element. 3.8.1 blow-out back a safety device incorporating the greater part of the back of the case 3.8.2 baffle wal
35、l a barrier between the pressure responsive element and the dial, so disposed that, in the event of a leakage or burst in the pressure responsive element, the blast would be dissipated away from the front 3.8.3 removable back plate a plate at the back of the case, that is removable for the purpose o
36、f giving access to the interior 3.9 flange the circular, square or rectangular part, removable or fixed, projecting from the case, on which the latter is mounted 3.10 window the transparent front intended for protection of the pointer, dial and control devices, if anyEN472:1994 BSI 01-2000 5 3.11 be
37、zel ring the part which retains the window on the case 3.12 clamp the part used for mounting clamp fixing pressure gauges on panel boards 3.13 spacer the distance piece, ring, or collar separating the window from the dial 3.14 dial that part of an indicating device, fixed or moving, which carries th
38、e scale or scales 3.15 scale (of an indicating device) An ordered set of scale marks, together with any associated numbering, forming a part of an indicating device. 3.15.1 scale length for a given scale, the length of the line between the first and the last scale marks and passing through the centr
39、es of all the shortest scale marks NOTEThe line may be real or imaginary, curved or straight. 3.15.2 scale range for a given scale, the set of scale values between the extreme scale marks NOTEThe scale range is expressed in the units marked on the scale, regardless of the units of the applied pressu
40、re and is normally stated in terms of its lower and upper limits, forexample0bar to100bar. 3.15.3 scale division the part of a scale between any two successive scale marks 3.15.4 scale spacing the distance between any two successive scale marks measured along the same line as the scale length NOTESc
41、ale spacing is expressed in units of length, regardless of the units of the applied pressure or the units marked on the scale. 3.15.5 scale numbering the set of numbers, associated with scale marks, which correspond to the set of values of the applied pressure defined by the scale marks 3.16 adjustm
42、ent operation of bringing a pressure gauge into a state of performance suitable for its use 3.17 user adjustment the operation intended to bring a pressure gauge into a state of performance and freedom from bias suitable for its use, employing only the means at the disposal of the user 4 Definitions
43、 relating to the characteristics 4.1 nominal size a conventional alpha-numerical designation relating to the size of the pressure gauge 4.2 nominal range for each scale range, the set of indicated values of the applied pressure for which a pressure gauge gives values within that scale range NOTEThe
44、nominal range is expressed in units of the applied pressure regardless of the units marked on the scale, and is normally stated in terms of its lower and upper limits, forexample200mbar to+400mbar. 4.3 span the modulus of the difference between the two limits of a nominal range of a pressure gauge E
45、XAMPLE Nominal range200mbar to+400mbar: span600mbar. 4.4 specified measuring range the set of values of an applied pressure for which the error of a pressure gauge is intended to lie within specified limits 4.5 accuracy class a class of pressure gauge which meets certain metrological requirements th
46、at are intended to keep errors within specified limits NOTEAn accuracy class is usually denoted by a number adopted by convention and called the class index. 4.6 limits of permissible error the extreme values of an error permitted by specifications, regulationsetc. for a given pressure gaugeEN472:19
47、94 6 BSI 01-2000 4.7 error (of indication) of a pressure gauge the indication of a pressure gauge minus the true value of the applied pressure 4.8 repeatability of a pressure gauge the ability of a pressure gauge to give, under defined conditions of use, closely similar responses for repeated applic
48、ations of the same stimulus NOTEThe defined conditions of use are usually as follows: repetition over a short period of time; use at the same location under constant ambient conditions; reduction to a minimum of the variations due to the observer. 4.9 hysteresis the property of a pressure gauge wher
49、eby its response to a given stimulus depends on the sequence of preceding stimuli NOTEAlthough hysteresis is normally considered in relation to the applied pressure, it may also be considered in relation to influence quantities.EN472:1994 BSI 01-2000 7 Index A absolute pressure gauge2.6 accuracy class4.6 adjustable mark3.6 adjustable pointer3.5.1 adjustment3.16 B baffle wall3.8.2 bellows3.1.4 bezel ring3.11 blow-out back3.2.1 blow-out device3.8 Bourdon tube3.1.1 C capsule3.1.3 case3.7 clamp3.12 combined pressure and vacuum gauge3.5 connection3.4
