SIST EN IEC 61298-2:2026

• Status: Not Published
• Public Enquiry End Date: 24-Nov-2024
• ICS: 25.040.40 - Industrial process measurement and control
• Technical Committee: MOV - Measuring equipment for electromagnetic quantities
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 18-Aug-2026
• Due Date: 23-Oct-2026
• Ref Project: EN IEC 61298-2:2026 - Process measurement and control devices - General methods and procedures for evaluating performance - Part 2: Tests under reference conditions

• Refers: SIST IEC 60050-371:1997 - International Electrotechnical Vocabulary. Chapter 371: Telecontrol
• Effective Date: 07-Jul-2026
• Refers: SIST EN 61010-1:2010 - Safety requirements for electrical equipment for measurement, control and laboratory use - Part 1: General requirements (IEC 61010-1:2010)
• Effective Date: 07-Jul-2026
• Referred By: SIST EN 60770-2:2011 - Transmitters for use in industrial-process control systems - Part 2: Methods for inspection and routine testing (IEC 60770-2:2010)
• Effective Date: 18-Aug-2026
• Referred By: SIST EN 60770-1:2011 - Transmitters for use in industrial-process control systems - Part 1: Methods for performance evaluation (IEC 60770-1:2010)
• Effective Date: 18-Aug-2026
• Referred By: SIST EN 60534-2-3:2016 - Industrial-process control valves -- Part 2-3: Flow capacity - Test procedures (IEC 60534-2-3:2015)
• Effective Date: 18-Aug-2026
• Referred By: SIST EN 61003-2:2010 - Industrial-process control systems - Instruments with analogue inputs and two- or multi-state outputs -- Part 2: Guidance for inspection and routine testing
• Effective Date: 18-Aug-2026
• Referred By: SIST EN IEC 61987-1:2025 - Industrial-process measurement and control - Data structures and elements in process equipment catalogues - Part 1: Generic structures for measuring equipment (IEC 61987-1:2024)
• Effective Date: 18-Aug-2026
• Referred By: SIST EN 61003-2:2017 - Industrial-Process control systems - Instruments with analogue inputs and two- or multi-position outputs - Part 2: Guidance for inspection and routine testing (IEC 61003-2:2016)
• Effective Date: 18-Aug-2026
• Referred By: SIST EN IEC 61298-1:2026 - Process measurement and control devices - General methods and procedures for evaluating performance - Part 1: General considerations (IEC 61298-1:2026)
• Effective Date: 07-Jul-2026
• Referred By: SIST EN IEC 61298-3:2026 - Process measurement and control devices - General methods and procedures for evaluating performance - Part 3: Tests for the effects of influence quantities (IEC 61298-3:2026)
• Effective Date: 07-Jul-2026
• Revises: SIST EN 61298-2:2009 - Process measurement and control devices - General methods and procedures for evaluating performance -- Part 2: Tests under reference conditions
• Effective Date: 26-Sep-2023

SIST EN IEC 61298-2:2026 is the Slovenian adoption of IEC 61298-2 for process measurement and control devices. It specifies general methods and procedures for testing the functional and performance characteristics of process instrumentation under reference conditions. The document is meant for manufacturers, test laboratories, quality teams, and product-standard writers working with analogue and digital devices that have defined input and output variables.

What does SIST EN IEC 61298-2:2026 specify?

SIST EN IEC 61298-2:2026 specifies how to test process measurement and control devices under reference conditions and how to report the results. It applies to devices with their own transfer function between input and output, and it is used together with a product-specific standard when special tests are needed.

The standard excludes Process Measurement Transmitters (PMT), which are standardized separately by the IEC 62828 series. That matters in practice because a buyer or engineer can use this part for many process instruments, but should not treat it as the test basis for PMT.

The document is organized into clauses on scope, normative references, terms and definitions, accuracy related factors, dynamic behavior, functional characteristic, and drift. Those clauses mirror the main questions users ask in a test program: how to set up the device, what to measure, and how to report performance in a comparable way.

What are the key requirements of SIST EN IEC 61298-2:2026?

SIST EN IEC 61298-2:2026 focuses on repeatable test methods rather than design requirements. The key point is that results are obtained under controlled reference conditions so that different devices, and different test labs, can be compared on the same basis.

Accuracy-related testing

For accuracy-related factors, the standard requires tests across the available ranges and settings, including switched ranges and adjustable span or lower range value settings. If a device is supplied calibrated for use, the first test is done without adjustment. This matters because the reported performance should reflect the device as delivered and as configured for use.

Before recording observations, the device under test is preconditioned and exercised through full-range traverses in both directions. The measurements are then taken over the full range with increasing and decreasing input values, using the smallest practical number of cycles and test points. In practice, this gives enough data to compare upward and downward behavior without making the test unnecessarily long.

The standard also gives a procedure for digital inputs and outputs. Protocol compliance, logic levels, display behavior, brightness, contrast, viewing angle, and update rate are checked where these features are provided. That is important because a modern process device may be judged not only by its analog accuracy but also by how reliably it communicates and displays data.

How the measured data are treated

The measured output errors are compared with ideal values, then tabulated and graphed. The standard then derives inaccuracy, maximum measured error, non-linearity or non-conformity, hysteresis, and non-repeatability from those records. These are not statistical estimates; they are calculated in a simple, defined way from the test results.

That approach matters because it gives a common language for specifications and acceptance checks. A manufacturer can state one of several accuracy formats, and the test report shows the corresponding measured values beside the claimed ones.

Dead band

SIST EN IEC 61298-2:2026 includes a separate procedure for dead band. The same ranges and preconditioning are used as for the accuracy tests, and the input is moved up and down until a detectable output change is seen.

This helps identify how much input movement is needed before the device responds. In practice, dead band is important for switches, control elements, and devices where small input changes should produce a visible output change.

Dynamic behavior

The dynamic behavior section uses both sinusoidal and step input signals. Frequency response testing produces gain and phase information over frequency, while step response testing shows how the device reacts to sudden changes. The point is to make dynamic performance comparable, not to model every possible operating condition.

The standard also calls for a realistic output load for electrical output devices and a defined approach to adjustable damping or filtering functions. For a reader, that means the test should reflect the device’s intended operating state, not an arbitrary bench setup.

Functional characteristics

The functional-characteristic section covers tests that are often needed for design verification or specification checks:

• input resistance of electrical devices
• insulation resistance and dielectric strength
• electrical power consumption and air consumption
• output ripple on devices with electrical d.c. output
• airflow characteristics of pneumatic devices
• limits of adjustment for lower range value and span
• switching differential

These tests matter because they check whether the device will interface correctly with the rest of the system, stay within safety expectations, and behave consistently under the specified supply and load conditions.

Drift

The drift section covers start-up drift and long-term drift. Start-up drift looks at the change in output after energizing the device, and long-term drift looks at output change over an extended operating period. That tells users whether a device stabilizes quickly after power-up and whether its output stays consistent over time.

What terms does SIST EN IEC 61298-2:2026 define?

• Device Under Test (DUT) - the device being examined in the test program.
• Non-conformity - the closeness of a calibration curve to a specified non-linear characteristic curve, without hysteresis.
• Dead-time - the interval between a change in input and the start of the corresponding output change.
• Settling time - the time until the output stays within a specified tolerance of its final value.
• Step response time - the time for the output to first reach a specified percentage of the final change after a step input.
• Time constant - the time needed for a first-order linear system to complete a specified portion of its total output change after a step input.
• Performance evaluation - a complete test to establish performance under likely operating conditions for comparison with published specifications or user requirements.
• Routine test - a simplified test applied to each individual instrument during or after manufacture.

Who uses SIST EN IEC 61298-2:2026?

Manufacturers of process measurement and control devices use SIST EN IEC 61298-2:2026 to design test programs and prepare performance data. Test laboratories and certification bodies use it to run comparable tests for accuracy, dynamics, insulation, power, pneumatic behavior, and drift.

Quality managers use it when they need a documented basis for comparing measured performance with a supplier’s stated specification. Product-standard writers use it as a common test framework when developing more specific standards for a device family. Buyers and users in industrial process measurement and control use it to judge whether a device’s published performance claims are being measured in a consistent way.

What changed in SIST EN IEC 61298-2:2026 from the previous edition?

SIST EN IEC 61298-2:2026 cancels and replaces the first edition published in 1995. The foreword describes it as a technical revision, and the introduction says it is a general revision without significant changes.

Which standards are used with SIST EN IEC 61298-2:2026?

• IEC 60050-300 - provides vocabulary for electrical and electronic measurements and measuring instruments.
• IEC 60050-351 - provides vocabulary for control technology, including terms used for switching and dynamic behavior.
• IEC 61298-1 - gives the general considerations used across the series, including shared test philosophy and preconditioning.
• IEC 61010-1 - provides the safety requirements referenced for electrical equipment used in measurement, control, and laboratory work.
• IEC 62828 series - standardizes Process Measurement Transmitters (PMT), which are excluded from this part.

What does the SIST EN IEC 61298-2:2026 document contain?

The document contains procedures for accuracy-related testing, dead band, dynamic behavior, functional characteristics, and drift. It also includes the test set-ups and reporting approach needed to make the results usable in type testing, routine testing, sample testing, and technical comparison.

It includes figures for error curves, frequency response, step response, input resistance, and airflow characteristics. It also includes tables for test-point planning, error presentation, and dielectric strength test voltages. For a lab or engineering team, these are the working tools used to set up the test, record the results, and present them in a standard form.

SLOVENSKI STANDARD
oSIST prEN IEC 61298-2:2024
01-november-2024
Naprave za merjenje in nadzor procesa - Splošne metode in postopki za
ocenjevanje lastnosti - 2. del: Preskusi pri referenčnih pogojih
Process measurement and control devices - General methods and procedures for
evaluating performance - Part 2: Tests under reference conditions
Prozessmess-, -steuer- und -regelgeräte – Allgemeine Methoden und Verfahren für die
Bewertung des Betriebsverhaltens – Teil 2: Prüfungen unter Referenzbedingungen
Dispositifs de mesure et de commande de processus - Méthodes et procédures
générales d'évaluation des performances - Partie 2: Essais dans les conditions de
référence
Ta slovenski standard je istoveten z: prEN IEC 61298-2:2024
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
oSIST prEN IEC 61298-2:2024 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

oSIST prEN IEC 61298-2:2024
oSIST prEN IEC 61298-2:2024
65B/1270/CDV
COMMITTEE DRAFT FOR VOTE (CDV)
PROJECT NUMBER:
IEC 61298-2 ED3
DATE OF CIRCULATION: CLOSING DATE FOR VOTING:
2024-09-06 2024-11-29
SUPERSEDES DOCUMENTS:
65B/1246/CD, 65B/1259/CC
IEC SC 65B : MEASUREMENT AND CONTROL DEVICES
SECRETARIAT: SECRETARY:
United States of America Mr Wallie Zoller
OF INTEREST TO THE FOLLOWING COMMITTEES: HORIZONTAL FUNCTION(S):

ASPECTS CONCERNED:
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The CENELEC members are invited to vote through the
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This document is still under study and subject to change. It should not be used for reference purposes.
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Recipients of this document are invited to submit, with their comments, notification of any relevant “In Some
Countries” clauses to be included should this proposal proceed. Recipients are reminded that the CDV stage is the
final stage for submitting ISC clauses. (SEE AC/22/2007 OR NEW GUIDANCE DOC).

TITLE:
Process measurement and control devices - General methods and procedures for evaluating
performance - Part 2: Tests under reference conditions

PROPOSED STABILITY DATE: 2028
NOTE FROM TC/SC OFFICERS:
download this electronic file, to make a copy and to print out the content for the sole purpose of preparing
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1 CONTENTS
2 FOREWORD . 4
3 INTRODUCTION . 6
4 1 Scope . 7
5 2 Normative references . 7
6 3 Terms and definitions . 7
7 4 Accuracy related factors . 8
8 4.1 Test procedures and precautions . 8
9 4.1.1 Selection of ranges for test . 8
10 4.1.2 Preconditioning cycles . 9
11 4.1.3 Number of measurement cycles and test points . 9
12 4.1.4 Additional tests where digital inputs and outputs are provided . 10
13 4.1.5 Measurement procedure . 10
14 4.1.6 Processing of the measured values . 10
15 4.1.7 Determination of accuracy related factors . 11
16 4.1.8 Presentation of the results . 14
17 4.2 Specific testing procedures and precautions for the determination of dead
18 band . 14
19 4.2.1 Selection of ranges for test and preconditioning . 14
20 4.2.2 Measurement procedure . 14
21 4.2.3 Presentation of the results . 15
22 5 Dynamic behavior . 15
23 5.1 General considerations . 15
24 5.2 General testing procedures and precautions . 15
25 5.3 Frequency response . 15
26 5.4 Step response . 17
27 6 Functional characteristic . 18
28 6.1 General . 18
29 6.2 Input resistance of an electrical device . 18
30 6.3 Insulation of electrical devices . 19
31 6.3.1 General considerations . 19
32 6.3.2 Insulation resistance . 19
33 6.3.3 Dielectric strength . 20
34 6.4 Power consumption . 20
35 6.4.1 Electrical power consumption . 20
36 6.4.2 Air consumption . 20
37 6.5 Output ripple of a device with an electrical d.c. output . 21
38 6.6 Air flow characteristics of a pneumatic device . 21
39 6.6.1 Initial setting up . 21
40 6.6.2 Delivered flow Q . 21
41 6.6.3 Exhausted flow Q . 22
42 6.6.4 Data presentation . 22
43 6.7 Limits of adjustments of lower range value and span . 23
44 6.8 Switching differential . 23
45 7 Drift . 23
46 7.1 Start-up drift . 23
47 7.2 Long-term drift . 23

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49 Figure 1 – Error curves . 13
50 Figure 2 – Two examples of frequency response . 16
51 Figure 3 – Two examples of responses to a step input . 17
52 Figure 3 – Two examples of responses to a step input . 18
53 Figure 4 – Test set-up for input resistance . 19
54 Figure 5 – Test arrangement for measurement of airflow characteristics . 21
55 Figure 6 – Typical air flow characteristics . 22
57 Table 1 – Settings of span and lower range value adjustments . 9
58 Table 2 – Number of measurement cycles and number and location of test points . 10
59 Table 3 – Typical table of device errors . 12
60 Table 4 – Dielectric strength test voltages . 20
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64 INTERNATIONAL ELECTROTECHNICAL COMMISSION
65 ____________
67 PROCESS MEASUREMENT AND CONTROL DEVICES –
68 GENERAL METHODS AND PROCEDURES
69 FOR EVALUATING PERFORMANCE –
71 Part 2: Tests under reference conditions
74 FOREWORD
75 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
76 all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
77 international co-operation on all questions concerning standardization in the electrical and electronic fields. To
78 this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
79 Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
80 Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested
81 in the subject dealt with may participate in this preparatory work. International, governmental and non-
82 governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely
83 with the International Organization for Standardization (ISO) in accordance with conditions determined by
84 agreement between the two organizations.
85 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
86 consensus of opinion on the relevant subjects since each technical committee has representation from all
87 interested IEC National Committees.
88 3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
89 Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
90 Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
91 misinterpretation by any end user.
92 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
93 transparently to the maximum extent possible in their national and regional publications. Any divergence
94 between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
95 the latter.
96 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
97 equipment declared to be in conformity with an IEC Publication.
98 6) All users should ensure that they have the latest edition of this publication.
99 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
100 members of its technical committees and IEC National Committees for any personal injury, property damage or
101 other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
102 expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
103 Publications.
104 8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
105 indispensable for the correct application of this publication.
106 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
107 patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
108 International Standard IEC 61298-2 has been prepared by subcommittee 65B: Devices and
109 process analysis, of IEC technical committee 65: Industrial-process measurement, control and
110 automation.
111 This second edition cancels and replaces the first edition published in 1995 and constitutes a
112 technical revision.
113 This edition is a general revision with respect to the previous edition and does not include any
114 significant changes (see Introduction).
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116 The text of this standard is based on the following documents:
FDIS Report on voting
65B/686/FDIS 65B/694/RVD
118 Full information on the voting for the approval of this standard can be found in the report on
119 voting indicated in the above table.
120 This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
121 A list of all parts of the IEC 61298 series, under the general title Process measurement and
122 control devices – General methods and procedures for evaluating performance, can be found
123 on the IEC website.
124 The committee has decided that the contents of this publication will remain unchanged until
125 the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
126 the data related to the specific publication. At this date, the publication will be
127 • reconfirmed,
128 • withdrawn,
129 • replaced by a revised edition, or
130 • amended.
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133 INTRODUCTION
134 This standard is not intended as a substitute for existing standards, but is rather intended as a
135 reference document for any future standards developed within the IEC or other standards
136 organizations, concerning the evaluation of process instrumentation, except the Process
137 Measurement Transmitters (PMT) which are standardized by IEC series 62828. .
138 This common standardized basis should be utilized for the preparation of future relevant
139 standards, as follows:
140 – any test method or procedure, already treated in this standard, should be specified and
141 described in the new standard by referring to the corresponding clause of this standard.
142 Consequently new editions of this standard are revised without any change in numbering
143 and scope of each clause;
144 – any particular method or procedure, not covered by this standard, should be developed
145 and specified in the new standard in accordance with the criteria, as far as they are
146 applicable, stated in this standard;
147 – any conceptual or significant deviation from the content of this standard, should be clearly
148 identified and justified if introduced in a new standard.
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151 PROCESS MEASUREMENT AND CONTROL DEVICES –
152 GENERAL METHODS AND PROCEDURES
153 FOR EVALUATING PERFORMANCE –
155 Part 2: Tests under reference conditions
159 1 Scope
160 This part of IEC 61298 specifies general methods and procedures for conducting tests and
161 reporting on the functional and performance characteristics of process instrumentation except
162 Process Measurement Transmitters (PMT) which are standardized by IEC series 62828. The
163 tests are applicable to any such devices characterized by their own specific input and output
164 variables, and by the specific relationship (transfer function) between the inputs and outputs,
165 and include analogue and digital devices. For devices that require special tests, this standard
166 should be used, together with any product specific standard specifying special tests.
167 This standard covers tests made under reference conditions.
168 2 Normative references
169 The following referenced documents are indispensable for the application of this document.
170 For dated references, only the edition cited applies. For undated references, the latest edition
171 of the referenced document (including any amendments) applies.
172 IEC 60050-300, International Electrotechnical Vocabulary (IEV) – Electrical and electronic
173 measurements and measuring instruments (composed of Part 311, 312, 313 and 314)
174 IEC 60050-351, International Electrotechnical Vocabulary (IEV) – Part 351 : Control
175 technology
176 IEC 61298-1, Process measurement and control devices – General methods and procedures
177 for evaluating performance – Part 1: General considerations
178 IEC 61010-1, Safety requirements for electrical equipment for measurement, control, and
179 laboratory use – Part 1: General requirements
180 3 Terms and definitions
181 For the purpose of this document, the following relevant terms and definitions, some of them
182 based main on IEC 60050(300) or IEC 60050(351), apply.
183 3.1
184 non-conformity
185 the closeness with which a calibration curve approximates to a specified characteristic curve
186 (which can be linear, logarithmic, parabolic, etc.)
187 NOTE Non-conformity does not include hysteresis.
188 3.2
189 dead-time
190 time interval between the instant when a variation of an input variable is produced, and the
191 instant when the subsequent variation of the output variable starts

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192 [IEV351-50-30, modified]
193 3.3
194 rise time
195 for a step response, the duration of the time interval between the instant when the output
196 variable (starting from zero) reaches a small specified percentage (for instance 10 %) of the
197 final steady-state value, and the instant when it reaches for the first time a large specified
198 percentage (for instance 90 %) of the same difference
199 [IEV845-25-067, modified]
200 3.4
201 settling time
202 time interval between the instant of the step change of an input variable, and the instant when
203 the output variable does not deviate by more than a specified tolerance from its final steady
204 state value. For this standard, a tolerance of 1 % is adopted
205 [IEV351-45-37]
206 3.5
207 step response time
208 time interval between the instant of a step change in the input variable and the instant when
209 the output variable reaches for the first time a specified percentage of the difference between
210 the final and the initial steady state value. For this standard , a specified percentage of 90 %
211 is adopted
212 [IEV 351-45-36]
213 3.6
214 time constant
215 time required to complete 63,2 % of the total change of the output of a first-order linear
216 system, produced by a step variation of the input variable
217 [IEV351-45-32]
218 3.7
219 performance evaluation
220 a complete test to establish the performance of a device under any likely operating conditions
221 to permit comparison with the manufacturer’s published or stated performance specification
222 for the device, or the user’s requirements
223 3.8
224 routine test
225 a simplified test to which each individual instrument is subjected during or after manufacture
226 to ascertain whether it complies with certain criteria
227 3.9
228 sample test
229 a simplified test to check specific characteristics of a device
230 4 Accuracy related factors
231 4.1 Test procedures and precautions
232 4.1.1 Selection of ranges for test
233 Where there are switched ranges or dial settings (e.g., gain), the tests shall be repeated to
234 cover all ranges or settings. When the Device Under Test (DUT) is supplied calibrated for use,
235 the first set of tests shall be carried out without adjustment.

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236 4.1.1.1 Criteria
237 The measurements shall be performed with the devices operating at the minimum number of
238 calibration settings necessary to establish the device performance in all required operational
239 settings required by the test program (see Clause 5 of IEC 61298-1).
240 Testing of a device which has provision for substantial adjustment of both span and lower
241 range value may require an impractically large number of tests. In such a case, preliminary
242 tests shall be conducted to determine the effect of changing span and lower range value
243 adjustments on the characteristic being measured. This should enable some tests to be
244 eliminated from the test program in cases where the characteristic can be inferred reliably
245 from fewer tests. For example, hysteresis may not be significantly affected by selection of the
246 lower and upper range value if the span is held constant, and often may be inferred for
247 different spans from measurements at a single span setting.
248 However, the report shall indicate clearly relevant values of the measured parameters for
249 each setting of the adjustments, so that the values of inaccuracy, hysteresis, etc, can all be
250 referenced to the same adjustment of the device.
251 4.1.1.2 Setting of span and lower range value adjustments
252 Generally, unless otherwise specified in the test program, the test for accuracy related factors
253 shall be carried out with the adjustments set at the settings A, B, C, D, listed below, and in
254 accordance with Table 1 whenever the span and/or the lower range value adjustments are
255 adjustable further than the adjustments for the manufacturing tolerances.
256 NOTE For tests of dynamic behavior, functional characteristics, and drift, refer to the appropriate clauses of this
257 standard.
258 Table 1 – Settings of span and lower range value adjustments
Zero suppression
Kind of test Adjustable span
and/or elevation
Complete Performance evaluation
A B
Tests Type test
Simplified Routine tests
C D
Tests Sample test
260 Setting A – Span adjustment set at the maximum and minimum values specified by the
261 manufacturer, and at one intermediate value.
262 Setting B – Normally, tests will be done at only one setting of lower range value, without
263 suppression or elevation, but further tests at minimum and maximum settings
264 may be required if the effects are significant.
265 Setting C – Unless otherwise specified in the test programme, the span shall be as set by
266 the manufacturer.
267 Setting D – Unless otherwise specified in the test programme, the lower range value shall
268 be as set by the manufacturer.
269 4.1.2 Preconditioning cycles
270 Prior to recording observations, the DUT shall be preconditioned (see 7.12 of IEC 61298-1)
271 and shall be exercised by three full range traverses in each direction.
272 4.1.3 Number of measurement cycles and test points
273 The performance of the DUT shall be verified over the full range for increasing and
274 decreasing values.
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275 Taking into account the economic aspects outlined in 5.2 of IEC 61298-1, the number of
276 measurement cycles and of test points shall be the lowest possible. The number and location
277 of the test points shall be consistent with the kind of test, the degree of accuracy desired, and
278 the characteristic being evaluated.
279 The number of increasing and decreasing test points shall be the same for each pre-
280 determined test point, with the exception of 0 % and 100 %, that are reached only when going
281 downscale or upscale.
282 The number of measurement cycles and the number of the test points depend on the kind of
283 test under consideration. Unless otherwise specified for a particular type of device, the values
284 and locations that should be adopted are given in Table 2.
285 4.1.4 Additional tests where digital inputs and outputs are provided
286 Tests shall be made to ensure that the protocols comply with international standards (e.g., RS
287 232, IEEE 488) or the protocols fully specified by the DUT supplier. Tests shall be carried out
288 to confirm that the DUT functions correctly to the specified protocol under reference
289 conditions, and without error (or within any error rate specified by the supplier). The levels of
290 logical "1" and "0" shall be determined. Appropriate tests shall also be made for display errors
291 (missing digit sections, etc.), brightness, contrast, and angle of view before loss of
292 brightness/contrast. The update rate shall be recorded, together with display (accuracy)
293 errors.
294 4.1.5 Measurement procedure
295 The first measurement shall be performed to the first significant value of the scale after 0 % of
296 input span (e.g., 10 % of input span – see Table 2).
297 Initially, an input signal equal to the lower range value is generated, and then the input signal
298 is slowly increased to reach, without overshoot, the first test point; after an adequate
299 stabilization period, the value of the corresponding input and output signal is noted.
300 Then the input signal is slowly increased to reach, without overshoot, the value of the next
301 test point and, after a stabilization period, the corresponding value of the output signal is
302 recorded.
303 The operation is repeated for all the predetermined values up to 100 % of the input span.
304 After measurement at this point, the input signal is slowly brought down to the test value
305 directly below 100 % of input span, and then to all the other values in turn down to 0 % of
306 input span, thus closing the measurement cycle.
307 Table 2 – Number of measurement cycles and number and location of test points
Number of Location of
Number
Kind of test measurement test points
of test points
cycles (% of input span)
Complete Performance 6 0-20-40-60-80-100
evaluation
3 or 5
Tests Type tests 11 0-10-20-30-40-50-60-70-80-90-100
Simplified Routine tests 1 5 0-25-50-75-100
Tests Sample tests
309 4.1.6 Processing of the measured values
310 The difference between the output signal values obtained at the various test points for each
311 upscale and downscale traverse and the corresponding ideal values are recorded as the
312 output errors.
oSIST prEN IEC 61298-2:2024
IEC CDV 61298-2 ED3 © IEC 2024 -11- 65B/1270/CDV

313 The errors generally shall be expressed as percent of the ideal output span. On certain
314 devices (e.g., recorders, or devices with adjustable gain), it may be more convenient to
315 express the errors as percent of nominal input span (see 7.16 of IEC 61298-1).
316 For each measuring point, the readings obtained in successive cycles for upscale and
317 downscale error, respectively, shall be averaged to give average upscale and downscale
318 values, and these averaged to give the average value at that point.
319 All the error values thus obtained shall be shown in a table (see Table 3), and the average
320 values shall be presented graphically (see Figure 1).
321 4.1.7 Determination of accuracy related factors
322 Because of the limited number of measurements (see 4.1.3), the accuracy related factors
323 shall be determined by treating the errors in a mathematically simple wa
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