1、DEUTSCHE NORM November 1994 Pressure gauges Vocabulary English version of DIN EN 472 I EN472 ICs 01.040.17; 17.100 Descriptors: Pressure gauge, vocabulary, measuring instrument. Druckmegerte; Begriffe European Standard EN 472: 1994 has the status of a DIN Standard. National foreword This standard ha
2、s been prepared by CENITC 141. The responsible German body involved in its preparation was the Normenausschu Primre Megerate und -einrich- tungen (Measuring Instruments Standards Committee). International Patent Classification G O1 L 007fOO EN comprises 10 pages. Ith Verlag GmbH, Berlin, has the exc
3、lusive right of sale for German Standards (DIN-Normen). DIN EN 472 Engl. Price group O Sales No. 11 07 05.95 EUROPEAN STANDARD NORME EUROPENNE EUROPAISCHE NORM EN 472 October 1994 UDC 681.2.084.83 :001.4 Descriptors: Pressure gauge, vocabulary, measuring instrument. English version Pressure gauges V
4、ocabulary Manomtres; vocabulaire Druckmegerte; Begriffe This European Standard was approved by CEN on 1994-10-19. CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any al
5、teration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any GEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by tra
6、nslation 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, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembo
7、urg, 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, 8-1050 Brussels - O 1994. Copyright reserved to all CEN members. Ref. N
8、o. EN 472 : 1994 E Page 2 EN 472 : 1994 Contents Foreword . O Introduction 1 scope . 2 Definitions relating to pressure gauges . 3 Definitions relating to pressure gauge components . 4 Definitions relating to the characteristics . Annex A (informative) Index Page . 2 . 2 . 3 . 3 . 4 . I . 9 Foreword
9、 This European Standard has been prepared by CENDC 141 ?Pressure gauges?, the Secretariat of which is held by AFNOR. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, and conflicting national standards withdrawn, by
10、 April 1995 at the latest. In accordance with the CENKENELEC Internal Regulations, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Sw
11、itzerland and United Kingdom. O Introduction In the preparation of this European Standard, the following two principles have been followed as far as possible: - to standardize suitable terms without perpetuating unsuitable terms merely because they have been used in the past; - to discard any term w
12、hich is used with different meanings and to replace it by a term which has an unequivocal meaning. Page 3 EN 472 : 1994 1 Scope This European Standard defines the fundamental and general terms to be used for pressure gauges. 2 Definitions relating to pressure gauges 2.1 Indicating pressure gauge: A
13、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 sequence directly transmits the elastic deformation of the sensing element t
14、o 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) vacuum with respect to the atmospheric pressure. 2.5 combined press
15、ure 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. pres- sure relative to a complete vacuum. NOTE: This description therefore does not apply to pressure g
16、auges 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 vacuum values, the metallic pressure-responsive element (s)
17、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 control pressure gauge: A pressure gauge fitted with one
18、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 pointer lies in a plane parallel to the plane of
19、 the panel or controlboard. Page 4 EN 472 : 1994 2.11 llquid fflled pressure gauge: A pressure gauge, the case of which is filled with a liquid. 2.12 safety pattern gauge: A gauge incorporating saftey features and parti- cularly suitable for use with high pressure gases and steam. 3 Definitions rela
20、ting 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 spiral pressure-responsi
21、ve 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 applied. 3.1.2 diaphragm: A type of pressure-responsive element
22、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 pressure-tight around their circumference.
23、 The pressure cmonly 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 its lengths Is proportioned to the pressure. 3.2 movement: pressure
24、-responsive element are transformed and enlarged into an angular vari at i on . An assembly by means of which the deformations of the 3.3 pressure element assembly: The assembly of all the pieces coming into contact with the fluid whose pressure fs measured. 3.4 connection: lhe part by which the pre
25、ssure gauge can be coupled to the pressure tapping of the plant, pipework or equipment. 3.4.1 shank: The part of the gauge that incudes the screwed connection, the spanner flats, square or hexagon, the spigot, and the inlet orifice. Page 5 EN 472 : 1994 3.4.2 screwed connection: The threaded portion
26、 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 the
27、 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. NOTE: It 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 indi
28、cating 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-o
29、ut device: 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 ba
30、ffle wall: 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 th
31、e purpose of 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: lhe transparent front intended for protection of the pointer, dial and control devices, If any. Page 6 EN 472 :
32、 1994 3.11 bezel ring: The part which retains the window on the case. 3.12 clamp: lhe part used for mounting clamp fixing pressure gauges on panel boards . 3.13 spacer: lhe distance piece, ring, or collar separating the window from the dial. 3.14 dial: That part of an indicating device, fixed or mov
33、ing, which carries the 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 devi ce. 3.15.1 scale length: For a given scale, the length of the line between the first and the last scale marks and
34、passing through the centres of all the shortest scale marks. NOTE: The 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. NOTE: The scale range is expressed in the units marked on the scale, regardless of
35、 the units of the applied pressure and is normally stated in terms of its lower and upper limits, for example O bar to 100 bar. 3.15.3 scale division: The part of a scale between any two successive scale marks. 3.15.4 scale spacing: lhe distance between any two successive scale marks measured along
36、the same line as the scale length. NOTE: Scale 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 pres
37、sure defined by the scale marks. 3.16 adjustment: Operation of brngfng a pressure gauge into a state of performance sui table for i ts use. Page 7 EN 472 : 1994 3.17 user adjustment: The operation intended to bring a pressure gauge into a state of performance and freedom from bias suitable for its u
38、se, employing only the means at the disposal of the user. 4 Definitions 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 pressur
39、e for which a pressure gauge gives values within that scale range. NOTE - The nominal range is expressed in units of the applied pressure re- gardless of the units marked on the scale, and is normally stated in terms of its lower and upper limits, for example -200 mbar to +400 mbar. 4.3 span: lhe mo
40、dulus of the difference between the two limits of a nominal range of a pressure gauge. EXAMPLE Nominal range -200 mbar to +400 mbar: span 600 mbar. 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 1 im
41、i ts. 4.5 accuracy class: A class of pressure gauge which meets certain metrological requirements that are intended to keep errors within specified 1 imi ts. NOTE - An accuracy class is usually denoted by a number adopted by convention and called the class index. 4.6 limits of permissible error: The
42、 extreme values of an error permitted by specifications, regulations etc. for a given pressure gauge. 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 gaug
43、e to give, under defined conditions of use, closely similar responses for repeated applications of the same stimulus. NOTE: lhe defined conditions of use are usually as follows: - repetftion over a short period of time, - use at the same location under constant ambient conditions, - reduction to a m
44、inimum of the variations due to the observer. Page 8 EN 472 : 1994 4.9 hysteresis: lhe property of a pressure gauge whereby its response to a given stimulus depends on the sequence of preceding stimuli. NOTE: Although hysteresis is normally considered in relation to the applied pressure, it my also
45、be considered in relation to influence quantities. Page 9 EN 472 : 1994 Index A absolute pressure gauge . 2.6 accuracy class 4.6 adjustable mark . 3.6 adjustable pointer 3.5.1 adjustment 3.16 B baffle wall . 3.8.2 bellows . 3.1.4 bezel ring 3.11 blow-out device . 3.8 bourdon tube 3.1.1 blow-Out back
46、 . 3.2.1 C capsule . 3.1.3 case 3.7 clamp . 3.12 combined pressure and vacuum gauge 3.5 control pressure gauge 2.9 connection 3.4 O dial 3.14 diaphragm . 3.1.2 differential pressure gauge . 2.7 duplex pressure gauge . 2.8 E edgewise pressure gauge . 2.10 error (of indication) of a pressure gauge . 4
47、.7 F flange 3.9 H hysteresis 4.9 .I indicating pressure gauge . 2.1 indicating pressure gauges with an elastic measuring element 2.2 L limits of permissible error . 4.6 liquid filled pressure gauge 2.11 Page 10 EN 472 : 1994 M maximum pointer . 3.5.2 movement 3.2 N nominal range . 4.2 nominal size 4
48、.1 nominal span 4.3 P pointer . 3.5 pointer stop 3.5.3 pressure element assembly . 3.3 pressure gauge 2.3 pressure-responsive element . 3.1 R removable back plate 3.8.2 repeatability of a pressure gauge . 4.8 s safety pattern gauge . scale (of an indicating device) . scale division scale length scale numbering . scale range . scale spacing . screwed connection shank . spacer specified measuring range . 2.12 3.15 3.15.3 3.15.1 3.15.5 3.15.2 3.15.4 3.4.2 3.4.1 3.13 4.4 U user adjustment . 3.17 V vacuum gauge 2.4 window 3.10
