SIST EN 61298-1:1998
(Main)Process measurement and control devices - General methods and procedures for evaluating performance -- Part 1: General considerations
Process measurement and control devices - General methods and procedures for evaluating performance -- Part 1: General considerations
Covers general principles which apply to the standard as a whole.
Prozeßmeß-, -steuer- und -regelgeräte - Allgemeine Methoden und Verfahren für die Bewertung des Betriebsverhaltens -- Teil 1: Allgemeine Betrachtungen
Dispositifs de mesure et de commande de processus - Méthodes et procédures générales d'évaluation des performances -- Partie 1: Généralités
Couvre les principes généraux qui s'appliquent à l'ensemble de la norme.
Process measurement and control devices - General methods and procedures for evaluating performance - Part 1: General considerations (IEC 61298-1:1995)
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Standards Content (Sample)
SLOVENSKI STANDARD
SIST EN 61298-1:1998
01-november-1998
Process measurement and control devices - General methods and procedures for
evaluating performance - Part 1: General considerations (IEC 61298-1:1995)
Process measurement and control devices - General methods and procedures for
evaluating performance -- Part 1: General considerations
Prozeßmeß-, -steuer- und -regelgeräte - Allgemeine Methoden und Verfahren für die
Bewertung des Betriebsverhaltens -- Teil 1: Allgemeine Betrachtungen
Dispositifs de mesure et de commande de processus - Méthodes et procédures
générales d'évaluation des performances -- Partie 1: Généralités
Ta slovenski standard je istoveten z: EN 61298-1:1995
ICS:
25.040.40 Merjenje in krmiljenje Industrial process
industrijskih postopkov measurement and control
SIST EN 61298-1:1998 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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NORME CEI
IEC
INTERNATIONALE
1298-1
INTERNATIONAL
Première édition
STANDARD
First edition
1995-07
Dispositifs de mesure et de commande
de processus —
Méthodes et procédures générales d'évaluation
des performances —
Partie 1:
Généralités
Process measurement and control devices —
General methods and procedures for
evaluating performance —
Part 1:
General considerations
Copyright — all rights reserved
CEI 1995 Droits de reproduction réservés —
©
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in writing from the publisher.
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1298-1 ©IEC:1995
CONTENTS
Page
FOREWORD 5
INTRODUCTION 7
Clause
1 Scope 9
2 Normative references 9
11 3 Definitions
13
4 Test categories
15
General criteria 5
15 5.1 Realistic operating conditions
15
5.2 Economic aspects
15
5.3 Replication of the tests and comparability of the results
17 5.4 Processing the results
17
5.5 Independence of the results of a test from the effects of other tests
17 6 General conditions for tests and samples
17 6.1 Environmental test conditions
19
6.2 Supply conditions
21
6.3 Load conditions
21
6.4 Mounting position
21
6.5 Externally induced vibrations
21
6.6 External mechanical constraints
23
6.7 Selection
23
6.8 Delivery of the devices
23
Identification and inspection
6.9
25 General testing procedures and precautions
7
25
7.1 Test laboratory
25
7.2 Preparation for the tests
25 7.3 Choice of reference measuring equipment
27
7.4 Input variable quality
27
7.5 Tapping
27 7.6 Checking of calibration made prior to delivery
27
7.7 Sequence of tests
27
7.8 Interruption and duration of each series of measurements
7.9 Anomalies and failures during tests 29
7.10 Re-start of a test 29
7.11 Setting of adjustments 29
29 7.12 Preconditioning
31
7.13 Calibration adjustments of lower range value and span
31 7.14 Constancy of the operating conditions and settings
7.15 Input/output variable relationships 31
33
7.16 Error assessment
33 7.17 Symbols and units of measurement
33 7.18 Test report and documentation
35 Annex A - Bibliography
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©IEC:1995 – 5 –
1298-1
INTERNATIONAL ELECTROTECHNICAL COMMISSION
PROCESS MEASUREMENT AND CONTROL DEVICES —
GENERAL METHODS AND PROCEDURES FOR
EVALUATING PERFORMANCE —
Part 1: General considerations
FOREWORD
The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
1)
comprising all national electrotechnical committees (IEC National Committees). The object of the IEC is to
promote international cooperation on all questions concerning standardization in the electrical and
electronic fields. To this end and in addition to other activities, the IEC publishes International Standards.
Their preparation is entrusted to technical committees; any IEC National Committee interested in
the subject dealt with may participate in this preparatory work. International, governmental and
non-governmental organizations liaising with the IEC also participate in this preparation. The IEC
collaborates closely with the International Organization for Standardization (ISO) in accordance with
conditions determined by agreement between the two organizations.
2) The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
which all the National Committees having a special interest therein are represented, express, as nearly as
possible, an international consensus of opinion on the subjects dealt with.
They have the form of recommendations for international use published in the form of standards, technical
3)
reports or guides and they are accepted by the National Committees in that sense.
In order to promote international unification, IEC National Committees undertake to apply IEC International
4)
Standards transparently to the maximum extent possible in their national and regional standards. Any
divergence between the IEC Standard and the corresponding national or regional standard shall be clearly
indicated in the latter.
International Standard IEC 1298-1 has been prepared by sub-committee 65B: Devices, of
IEC technical committee 65: Industrial-process measurement and control.
The text of this standard is based on the following documents:
Report on voting
DIS
65B/228/DIS 65B/217/RVD
Full information on the voting for the approval of this standard can be found in the repo rt
on voting indicated in the above table.
Process measurement and
IEC 1298 consists of the following parts under the general title:
control devices – General methods and procedures for evaluating performance.
– Part 1: General considerations
– Part 2: Tests under reference conditions
– Part 3: Tests for the effects of influence quantities
–
Part 4: Evaluation report content
Annex A is for information only.
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1298-1 © IEC:1995
INTRODUCTION
This standard is not intended as a substitute for existing standards, but is rather intended
document for any future standards developed within the IEC or other
as a reference
standards organizations, concerning the evaluation of process instrumentation. Any
revision of existing standards should take this standard into account.
This common standardized basis should be utilized for the preparation of future relevant
standards, as follows:
Any test method or procedure, already treated in this standard, should be specified
-
and described in the new standard by referring to the corresponding clause of this
standard.
- Any particular method or procedure, not covered by this standard, should be
developed and specified in the new standard 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
-
new standard.
clearly be identified and justified if introduced in a
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1298-1 © I EC:1995
PROCESS MEASUREMENT AND CONTROL DEVICES —
GENERAL METHODS AND PROCEDURES FOR
EVALUATING PERFORMANCE —
Part 1: General considerations
1 Scope
This International Standard specifies general methods and procedures for conducting
rformance characteristics of process measure-
tests, and reporting on the functional and pe
ment and control devices. The methods and procedures specified in this standard are ap-
plicable to any kind of test or to any type of process measurement and control device. The
tests are applicable to any such devices characterized by their own specific input and out-
put 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 standard shall be used, together with any product specific standard specifying special
tests.
of IEC 1298 covers general principles which apply to the standard as a whole.
This pa rt
2 Normative references
The following normative documents contain provisions which, through reference in this
of IEC 1298. At the time of publication, the editions
text, constitute provisions of this pa rt
indicated were valid. All normative documents are subject to revision, and pa rties to agree-
of IEC 1298 are encouraged to investigate the possibility of
ments based on this pa rt
applying the most recent editions of the normative documents indicated below. Members
of IEC and ISO maintain registers of currently valid International Standards.
IEC 410: 1973, Sampling plans and procedures for inspection by attributes
Industrial-process measurement and control - Terms and definitions
IEC 902: 1987,
Process measurement and control devices - General methods and
IEC 1298-2: 1995,
procedures for evaluating performance - Part 2: Tests under reference conditions
Process measurement and control devices - General methods and
IEC 1298-4: 1995,
procedures for evaluating performance - Part 4: Evaluation report content
ISO 31: Quantities and units
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1298-1 © IEC:1995 - 11 -
3 Definitions
For the purpose of this part of IEC 1298, the following definitions apply. Those marked
with an asterisk (*) are identical with those given in IEC 902, but that document has
additional notes.
The device under test.
3.1 DUT:
A quantity or condition whose value is subject to change and can usually
3.2 variable*:
be measured (e.g., temperature, flow rate, speed, signal, etc.).
3.3 signal*: Physical variable, one or more parameters of which carry information about
one or more variables which the signal represents.
Region of the values between the lower and upper limits of the quantity
3.4 ranges:
under consideration.
3.5 span*: Algebraic difference between the upper and lower limit values of a given
range.
3.6 set point*: Signal representing the reference variable.
NOTE — It may be manually set, automatically set, or programmed.
3.7 Inaccuracy*: Maximum positive and negative deviation from the specified charac-
teristic curve observed in testing a device under specified conditions and by a specified
procedure.
Algebraic difference between the measured value and the true value of the
3.8 error*:
measured variable.
NOTE — The error is positive when the measured value is greater than the true value. The error is
generally expressed as a percentage of the relevant ideal span.
3.9 maximum measured error: Largest positive or negative value of error of the
average upscale or downscale value at each point of measurement.
3.10 non-conformity: Deviation from conformity.
NOTE — Conformity is defined in IEC 902.
3.11 non-linearity: Deviation from linearity.
NOTES
1 Linearity is defined in IEC 902.
2 Non-conformity and non-linearity do not include hysteresis.
3.12 non-repeatability: See definition of repeatability error in IEC 902.
3.13 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.
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1298-1 © IEC:1995
Finite range of values within which variation of the input variable does
dead band*:
3.14
not produce any noticeable change in the output variable.
Smallest possible change in output produced by a change to the
3.15 adjustability:
adjusting mechanism.
Time interval between the instant when the variation of an input
dead time*:
3.16
variable is produced, and the instant when the consequent variation of the output variable
starts (see IEC 902, figure 1-2).
a step response, the time interval between the instant when the
3.17 rise time*: For
output signal, starting from zero, reaches a small specified percentage (for instance
10 %) of the final steady-state value, and the instant when it reaches for the first time
a specified large percentage (for instance 90 %) of the same steady-state value
(see IEC 902, figure 1-2).
Time interval between the step change of an input signal, and the
3.18 settling time:
instant when the resulting variation of the output signal does not deviate more than a
specified tolerance from its final steady-state value. For this standard, a tolerance of 1 %
is adopted.
Time from a step change in the input signal to a system for
step response time:
3.19
the change in output of the system to reach for the first time 90 % of its final steady-state
value (see IEC 902, figure 1-2).
Time required to complete 63,2 % of the total rise or decay of the
3.20 time constant*:
output of a first-order linear system, initiated by a step or an impulse to the input.
For a step response, the maximum transient deviation from
transient overshoot*:
3.21
the final steady-state value of the output variable, expressed in % of the difference
between the final and the original steady-state values.
Device breakdown, failure to work, anomaly, or inadvertent
3.22 unexpected event:
damage occurring during an evaluation, which requires correction by the device manu-
facturer.
Statement of the tests to be carried out, and the conditions for
procedure:
3.23 test
each test, agreed between the manufacturer, the test laboratory, and the purchaser/user
before the evaluation starts.
4 Test categories
The tests specified can be considered under two categories.
Complete tests: These cover performance evaluations or type tests to establish the
performance of a device under any likely operating conditions; to permit comparison with
the manufacturer's published or stated performance specification for the device, or the
user's requirements.
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1298-1 © I EC:1995
Simplified tests: These cover a selection of the complete tests to check specific character-
istics of a device (e.g., routine tests of all devices before delivery, or tests on a random
sample of devices).
Where the full range of tests is not carried out, this shall be stated in all reports on
the testing, and the reasons given (e.g., economy, lack of relevance to the particular
application, or failure of the device). Deviations from the test procedures specified shall
also be reported.
The programme of tests, prepared in accordance with this standard, shall be agreed
between the test house, the initiator/purchaser, and where appropriate, the device supplier
or manufacturer, before tests are commenced. Because of the generic nature of this
standard, the tests listed may be too extensive, or insufficiently comprehensive for a
particular requirement, and a modification of the test programme may be agreed.
The criteria for the acceptability of the test results (e.g., expected or limiting values), and
for judgement of the quality and acceptance of the device under test, are strictly related to
the subsequent use of the test results, and are outside the scope of this standard.
5 General criteria
5.1 Realistic operating conditions
Ideally, instruments should be evaluated under each of the conditions which they are likely
to meet in service. Unfortunately, it is not practical to evaluate performance under all
possible combinations of operating conditions. A standard test procedure is therefore
specified which is practical under laboratory conditions, and, at the same time, will make
, sufficient data on which a prediction of field
rt
available, with a reasonable amount of effo
performance can be made. Use of a small number of standard conditions covering the
range will simplify testing, and enable tests on different devices to be more readily
compared.
5.2 Economic aspects
The test procedures, and the number of test points and measurement cycles, shall be
chosen so as to obtain the best compromise between objectives and relevance of the
results on the one hand, and costs and technical difficulties of the test on the other.
Standard procedures should be used, but if tests are omitted or curtailed for economic or
other reasons, this shall be stated in the test report.
5.3 Replication of the tests and comparability of the results
To obtain comparable results from tests performed at different times and places, by
different operators, on different devices of the same type, the test procedures and
rticular, the following are required.
methods need to be well defined and reproducible. In pa
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1298-1 ©IEC:1995
Standardization of test methods
5.3.1
The test methods to be followed during the evaluation shall be decided before the start,
and shall conform with standardized test methods wherever possible. Deviation from
standard methods shall be reported.
Influence factors
5.3.2
DUT shall be
During the test, all the factors which might influence the behaviour of the
checked and maintained as constant as possible (with the exception of the specific
condition being tested).
Documentation of the test methods
5.3.3
shall indicate clearly the standards or standard referred to during the
rt
The test repo
evaluation, and state the test conditions and any deviation from the specified conditions
which has occurred during the evaluation (a format for a full report of an evaluation is
presented in IEC 1298-4).
Processing the results
5.4
Due to economic aspects (see 5.2), the number of measurements during a test is often
reduced to the minimum, and therefore it is statistically insignificant. Processing of the
results to obtain meaningful information from the evaluation, therefore, cannot be
performed following statistical methods, but it shall be performed following conventional
methods.
DUT
Consequently, in view of the general nature of the parameters characterizing the
inaccuracy, hysteresis, repeatability, dead band, etc.) the calculations are based on
(e.g.,
maximum values (positive and negative) of the difference between the measured value
and conventional true values, with the exception of a few quantities, for which use is made
of averaged values (e.g., measured error, linearity).
Independence of the results of a test from the effects of oth
...
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