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 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSINational 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
3、 iswithdrawn.The UK participation in its preparation was entrusted by Technical CommitteeGEL/65, Measurement 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
4、 include all the necessary provisions of acontract. Users are responsible for its correct application. 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 StandardsPo
5、licy and Strategy Committee on 31 October 2009Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSIEUROPEAN STANDARD EN 61298-2 NORME EUROPENNE EUROPISCHE NOR
6、M November 2008 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2008 CENELEC - All rights of exploitation in any form and by any
7、 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 procedures for evaluating performance - Part 2: Tests under reference conditions (IEC 61298-2:2008) Disposit
8、ifs 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 -regelgerte - Allgemeine Methoden und Verfahren fr die Bewertung des Betriebsverhaltens - Teil 2: Prfun
9、gen 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 stipulate the conditions for giving this European Standard the status of a national standard without any
10、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 Standard exists in three official versions (English, French, German). A version in any other language made
11、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 national electrotechnical committees of Austria, Belgium, Bulgaria, Cyprus, the Czech Republic, Denmark, Est
12、onia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STA
13、NDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSIEN 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 standard i
14、n 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 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA
15、 STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSI61298-2 IEC:2008 7 PROCESS MEASUREMENT AND 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
16、 tests and reporting on the functional and performance characteristics of process measurement and 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
17、outputs, and include analogue and digital devices. For devices that require special tests, this 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 d
18、ocuments are indispensable for the application of this document. For dated references, only the 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 a
19、nd electronic measurements and measuring instruments (composed of Part 311, 312, 313 and 314) IEC 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 Pa
20、rt 1: General considerations IEC 61010-1, Safety requirements for electrical equipment for measurement, 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
21、) or IEC 60050(351), apply. 3.1 variable quantity or condition whose value is subject to change 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 va
22、riables which the signal represents IEV 351-21-51, modified BS EN 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSI 8 61298-2 IEC:2008 3.3 range range of values defined by the two extreme values within which a variable can be measured wit
23、hin 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 positive and negative deviation from the specified characteristic curve observed in testing a device under spe
24、cified 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 term should not be used. 3.6 error algebraic difference between the indicated value and a comparison value o
25、f 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 relevant ideal span. 3.7 measured error largest positive or negative value of errors of the average upscal
26、e 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, logarithmic, parabolic, etc.) NOTE Non-conformity does not include hysteresis. 3.9 non-linearity deviation from li
27、nearity 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 Repeatability is defined in IEC 60050(300), definition 311-06-06. 3.11 hysteresis property of a device or instrument
28、 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 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSI612
29、98-2 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 insta
30、nt 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 10 %)
31、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 variab
32、le, 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 change
33、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 3.17 time
34、 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 manufacture
35、r, 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 all the
36、individual units of equipment made in series. BS EN 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSI 10 61298-2 IEC:2008 3.20 performance evaluation a complete test to establish the performance of a device under any likely operating cond
37、itions to permit comparison with the manufacturers published or stated performance specification 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 cr
38、iteria 3.22 sample test a simplified test to check specific characteristics of a device 4 Accuracy 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
39、settings. When the Device Under Test (DUT) is supplied calibrated for use, the first set of tests 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 p
40、erformance in all required operational settings required by the test programme (see Clause 5 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 sh
41、all be conducted to determine the effect of changing span and lower range value adjustments on 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, hysteresi
42、s may not be significantly affected by selection of the lower and upper range value if the span 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 s
43、etting of the adjustments, so that the values of inaccuracy, hysteresis, etc, can all be referenced 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
44、 be carried out with the adjustments set at the settings A, B, C, D, listed below, and in accordance 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 c
45、haracteristics, and drift, refer to the appropriate clauses of this standard. BS EN 61298-2:2008Licensed Copy: Wang Bin, ISO/EXCHANGE CHINA STANDARDS, 21/01/2010 02:01, Uncontrolled Copy, (c) BSI61298-2 IEC:2008 11 Table 1 Settings of span and lower range value adjustments Kind of test Adjustable sp
46、an 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 values specified by the manufacturer, and at one intermediate value. Setting B Normally, tests will be done
47、 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 otherwise specified in the test programme, the span shall be as set by the manufacturer. Setting D Unless ot
48、herwise 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 preconditioned (see 7.12 of IEC 61298-1) and shall be exercised by three full range traverses in each direction. 4.1.3 Nu
49、mber 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 outlined 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 inc
