1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI British StandardsWB9423_BSI_StandardColCov_noK_AW:BSI FRONT COVERS 5/9/08 12:55 Page 1Process measurement and control devices General methods and procedures for evaluating performance Part 2: Tests u
2、nder reference conditionsBS EN 61298-2:2008National forewordThis British Standard is the UK implementation of EN 61298-2:2008. It isidentical to IEC 61298-2:2008. It supersedes BS EN 61298-2:1996 which iswithdrawn.The UK participation in its preparation was entrusted by Technical CommitteeGEL/65, Me
3、asurement and control, to Subcommittee GEL/65/2, Elements ofsystems.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions of acontract. Users are responsible for its correct applicati
4、on. BSI 2009ISBN 978 0 580 55954 9ICS 25.040.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of the StandardsPolicy and Strategy Committee on 31 October 2009Amendments issued since publicationAmd. No. Date Text
5、 affectedBRITISH STANDARDBS EN 61298-2:2008EUROPEAN STANDARD EN 61298-2 NORME EUROPENNE EUROPISCHE NORM November 2008 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat:
6、rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61298-2:2008 E ICS 25.040.40 Supersedes EN 61298-2:1995English version Process measurement and control devices - General methods and proced
7、ures for evaluating performance - Part 2: Tests under reference conditions (IEC 61298-2:2008) Dispositifs de mesure et de commande de processus - Mthodes et procdures gnrales dvaluation des performances - Partie 2: Essais dans les conditions de rfrence (CEI 61298-2:2008) Prozessmess-, -steuer- und -
8、regelgerte - Allgemeine Methoden und Verfahren fr die Bewertung des Betriebsverhaltens - Teil 2: Prfungen unter Referenzbedingungen (IEC 61298-2:2008) This European Standard was approved by CENELEC on 2008-11-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which sti
9、pulate the conditions for giving 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 CENELEC member. This European Stand
10、ard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions. CENELEC members are the nation
11、al electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden,
12、 Switzerland and the United Kingdom. BS EN 61298-2:2008EN 61298-2:2008 - 2 - Foreword The text of document 65B/686/FDIS, future edition 2 of IEC 61298-2, prepared by SC 65B, Devices any particular method or procedure, not covered by this standard, should be developed and specified in the new standar
13、d in accordance with the criteria, as far as they are applicable, stated in this standard; any conceptual or significant deviation from the content of this standard, should be clearly identified and justified if introduced in a new standard. BS EN 61298-2:200861298-2 IEC:2008 7 PROCESS MEASUREMENT A
14、ND CONTROL DEVICES GENERAL METHODS AND PROCEDURES FOR EVALUATING PERFORMANCE Part 2: Tests under reference conditions 1 Scope This part of IEC 61298 specifies general methods and procedures for conducting tests and reporting on the functional and performance characteristics of process measurement an
15、d control devices. The tests are applicable to any such devices characterized by their own specific input and output variables, and by the specific relationship (transfer function) between the inputs and outputs, and include analogue and digital devices. For devices that require special tests, this
16、standard should be used, together with any product specific standard specifying special tests. This standard covers tests made under reference conditions. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the
17、edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050-300, International Electrotechnical Vocabulary (IEV) Electrical and electronic measurements and measuring instruments (composed of Part 311, 312, 313 and 314) IE
18、C 60050-351, International Electrotechnical Vocabulary (IEV) Part 351 : Control technology IEC 61298-1, Process measurement and control devices General methods and procedures for evaluating performance Part 1: General considerations IEC 61010-1, Safety requirements for electrical equipment for measu
19、rement, control, and laboratory use Part 1: General requirements 3 Terms and definitions For the purpose of this document, the following relevant terms and definitions, some of them based on IEC 60050(300) or IEC 60050(351), apply. 3.1 variable quantity or condition whose value is subject to change
20、and can usually be measured (e.g., temperature, flow rate, speed, signal, etc.) IEV 351-21-01, modified 3.2 signal physical quantity, one or more parameters of which carry information about one or more variables which the signal represents IEV 351-21-51, modified BS EN 61298-2:2008 8 61298-2 IEC:200
21、8 3.3 range range of values defined by the two extreme values within which a variable can be measured within the specified accuracy IEV 351-27-11, modified 3.4 span algebraic difference between the values of the upper and lower limits of the measuring range IEV 311-03-13 3.5 inaccuracy maximum posit
22、ive and negative deviation from the specified characteristic curve observed in testing a device under specified conditions and by a specified procedure NOTE 1 Accuracy is defined in IEC 60050-300, definition 311-06-08. NOTE 2 The term inaccuracy is sometime referred to as measured accuracy. This ter
23、m should not be used. 3.6 error algebraic difference between the indicated value and a comparison value of the measured variable IEV 351-27-04, modified NOTE The error is positive when the indicated value is greater than the comparison value. The error is generally expressed as a percentage of the r
24、elevant ideal span. 3.7 measured error largest positive or negative value of errors of the average upscale or downscale values at each point of measurement 3.8 non-conformity the closeness with which a calibration curve approximates to a specified characteristic curve (which can be linear, logarithm
25、ic, parabolic, etc.) NOTE Non-conformity does not include hysteresis. 3.9 non-linearity deviation from linearity NOTE 1 Linearity is defined in IEC 60050(300), definition 311-06-05. NOTE 2 Non-linearity does not include hysteresis. 3.10 non-repeatability deviation from repeatability NOTE Repeatabili
26、ty is defined in IEC 60050(300), definition 311-06-06. 3.11 hysteresis property of a device or instrument whereby it gives different output values in relation to its input values depending on the directional sequence in which the input values have been applied IEV 351-24-15, modified BS EN 61298-2:2
27、00861298-2 IEC:2008 9 3.12 dead band finite range of values within which a variation of the input variable does not produce any measurable change in the output variable IEV 351-24-14, modified 3.13 dead-time time interval between the instant when a variation of an input variable is produced, and the
28、 instant when the subsequent variation of the output variable starts IEV 351-28-41 (see IEC 60050-351, Figure 5) 3.14 rise time for a step response, the duration of the time interval between the instant when the output variable (starting from zero) reaches a small specified percentage (for instance
29、10 %) of the final steady-state value, and the instant when it reaches for the first time a large specified percentage (for instance 90 %) of the same difference IEV 394-39-11, modified (see IEC 60050-351, Figure 3) 3.15 settling time time interval between the instant of the step change of an input
30、variable, and the instant when the output variable does not deviate by more than a specified tolerance from its final steady state value (see IEC 60050-351, Figure 3). For this standard, a tolerance of 1 % is adopted IEV 351-24-29 3.16 step response time time interval between the instant of a step c
31、hange in the input variable and the instant when the output variable reaches for the first time a specified percentage of the difference between the final and the initial steady state value (see IEC 60050-351, Figure 3). For this standard , a specified percentage of 90 % is adopted IEV 351-24-28 3.1
32、7 time constant time required to complete 63,2 % of the total change of the output of a first-order linear system, produced by a step variation of the input variable IEV 351-24-24 3.18 test procedure statement of the tests to be carried out, and the conditions for each test, agreed between the manuf
33、acturer, the test laboratory, and the purchaser/user before the evaluation starts 3.19 type tests a test of one or more devices made to a certain design to show that the design meets certain specifications NOTE The type tests are in principle applied only on a sample. Normally are not repeated on al
34、l the individual units of equipment made in series. BS EN 61298-2:2008 10 61298-2 IEC:2008 3.20 performance evaluation a complete test to establish the performance of a device under any likely operating conditions to permit comparison with the manufacturers published or stated performance specificat
35、ion for the device, or the users requirements 3.21 routine test a simplified test to which each individual instrument is subjected during or after manufacture to ascertain whether it complies with certain criteria 3.22 sample test a simplified test to check specific characteristics of a device 4 Acc
36、uracy related factors 4.1 Test procedures and precautions 4.1.1 Selection of ranges for test Where there are switched ranges or dial settings (e.g., gain), the tests shall be repeated to cover all ranges or settings. When the Device Under Test (DUT) is supplied calibrated for use, the first set of t
37、ests shall be carried out without adjustment. 4.1.1.1 Criteria The measurements shall be performed with the devices operating at the minimum number of calibration settings necessary to establish the device performance in all required operational settings required by the test programme (see Clause 5
38、of IEC 61298-1). Testing of a device which has provision for substantial adjustment of both span and lower range value may require an impractically large number of tests. In such a case, preliminary tests shall be conducted to determine the effect of changing span and lower range value adjustments o
39、n the characteristic being measured. This should enable some tests to be eliminated from the test programme in cases where the characteristic can be inferred reliably from fewer tests. For example, hysteresis may not be significantly affected by selection of the lower and upper range value if the sp
40、an is held constant, and often may be inferred for different spans from measurements at a single span setting. However, the report shall indicate clearly relevant values of the measured parameters for each setting of the adjustments, so that the values of inaccuracy, hysteresis, etc, can all be refe
41、renced to the same adjustment of the device. 4.1.1.2 Setting of span and lower range value adjustments Generally, unless otherwise specified in the test programme, the test for accuracy related factors shall be carried out with the adjustments set at the settings A, B, C, D, listed below, and in acc
42、ordance with Table 1 whenever the span and/or the lower range value adjustments are adjustable further than the adjustments for the manufacturing tolerances. NOTE For tests of dynamic behaviour, functional characteristics, and drift, refer to the appropriate clauses of this standard. BS EN 61298-2:2
43、00861298-2 IEC:2008 11 Table 1 Settings of span and lower range value adjustments Kind of test Adjustable span Zero suppression and/or elevation Complete Performance evaluation Tests Type test A B Simplified Routine tests Tests Sample test C D Setting A Span adjustment set at the maximum and minimum
44、 values specified by the manufacturer, and at one intermediate value. Setting B Normally, tests will be done at only one setting of lower range value, without suppression or elevation, but further tests at minimum and maximum settings may be required if the effects are significant. Setting C Unless
45、otherwise specified in the test programme, the span shall be as set by the manufacturer. Setting D Unless otherwise specified in the test programme, the lower range value shall be as set by the manufacturer. 4.1.2 Preconditioning cycles Prior to recording observations, the DUT shall be preconditione
46、d (see 7.12 of IEC 61298-1) and shall be exercised by three full range traverses in each direction. 4.1.3 Number of measurement cycles and test points The performance of the DUT shall be verified over the full range for increasing and decreasing values. Taking into account the economic aspects outli
47、ned in 5.2 of IEC 61298-1, the number of measurement cycles and of test points shall be the lowest possible. The number and location of the test points shall be consistent with the kind of test, the degree of accuracy desired, and the characteristic being evaluated. The number of increasing and decr
48、easing test points shall be the same for each pre-determined test point, with the exception of 0 % and 100 %, that are reached only when going downscale or upscale. The number of measurement cycles and the number of the test points depend on the kind of test under consideration. Unless otherwise spe
49、cified for a particular type of device, the values and locations that should be adopted are given in Table 2. 4.1.4 Additional tests where digital inputs and outputs are provided Tests shall be made to ensure that the protocols comply with international standards (e.g., RS 232, IEEE 488) or the protocols fully specified by the DUT supplier. Tests shall be carried out to confirm that the DUT functions correctly to the specified protocol under reference conditions, and with
