EN 60060-2:1994

SLOVENSKI STANDARD
01-januar-1998
High-voltage test techniques - Part 2: Measuring systems (IEC 60060-2:1994)
High-voltage test techniques - Part 2: Measuring systems (IEC 60060-2:1994)
Hochspannungs-Prüftechnik -- Teil 2: Meßsysteme
Techniques des essais à haute tension -- Partie 2: Systèmes de mesure
Ta slovenski standard je istoveten z: EN 60060-2:1994
ICS:
19.080 (OHNWULþQRLQHOHNWURQVNR Electrical and electronic
SUHVNXãDQMH testing
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEI
NORME
IEC
INTERNATIONALE
60-2
INTERNATIONAL
Deuxième édition
STANDARD
Second edition
1994-11
Techniques des essais à haute tension
Partie 2:
Systèmes de Mesure
High-voltage test techniques
Part 2:
Measuring Systems
CEI 1994 Droits de reproduction réservés — Copyright — all rights reserved
©
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in
utilisée sous quelque forme que ce soit et par aucun pro- any form or by any means, electronic or mechanical,
cédé, électronique ou mécanique, y compris la photocopie et including photocopying and microfilm, without permission
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
Bureau Central de la Commission Electrotechnique Internationale 3, rue de Varembé Genève, Suisse
Commission Electrotechnique Internationale
CODE PRIX
International Electrotechnical Commission
PRICE CODEPRICE CODE
IEC Mes ayHapojHae 3nertrporextwvecnaa HOMHCCHR
• Pour prix, voir catalogue en vigueur
•
For price, see current catalogue

60-2 ©IEC:1994 - 3 -
CONTENTS
Page
FOREWORD 9
Clause
1 Scope 11
2 Normative references 13
3 Definitions and symbols 15
3.1 Measuring Systems 15
3.2 Converting devices 17
3.3 Transmission system 17
3.4 Indicating or recording instrument 17
3.5 Scale factors 19
3.6 Definition related to the dynamic behaviour of a Measuring System 19
3.7 Response parameters 21
3.8 Overall uncertainty e 23
3.9 Rated values 25
3.10 Definitions related to tests 25
4 Procedures for qualification and use of measuring systems 27
4.1 General principles 27
4.2 Schedule of Performance Tests 27
4.3 Schedule of Performance Checks 29
4.4 Requirements for the Record of Performance 29
4.5 Operating conditions 31
5 Acceptance tests on components for an Approved Measuring System 33
5.1 Applicability 33
5.2 Determination of the scale factor 33
5.3 Linearity test 33
5.4 Short-term stability test 35
5.5 Long-term stability of single elements 35
5.6 Temperature effect 35
5.7 Proximity effect 35
5.8 Dynamic behaviour of a component 37
5.9 Withstand tests 37
6 Performance Tests on Measuring Systems 39
6.1 General requirements 39
6.2 Determination of the Assigned Scale Factor 41
6.3 Dynamic behaviour test (for Impulse Measuring Systems) 43
6.4 Interference test (for Impulse Measuring Systems) 43

– 5 –
60-2 © I EC:1994
Page
Clause
7 Measurement of direct voltage
7.1 Requirements for an Approved Measuring System
7.2 Acceptance tests on components for an Approved Measuring System
7.3 Performance Test on Measuring Systems
49 7.4 Performance Check
7.5 IEC Standard Measuring Device 49
7.6 Measurement of ripple amplitude
8 Measurement of alternating voltage
53 8.1 Requirements for an Approved Measuring System
8.2 Acceptance tests on components for an Approved Measuring System
57 8.3 Performance Test on Measuring Systems
8.4 Performance Check
57 8.5 IEC Standard Measuring Device
9 Measurement of lightning impulse voltage
59 9.1 Requirements for an Approved Measuring System
9.2 Acceptance tests on components for an Approved Measuring System
9.3 Performance Test on Measuring Systems
9.4 Performance Check
9.5 IEC Standard Measuring Device
10 Measurement of switching impulse voltage 73
73 10.1 Requirements for an Approved Measuring System
73 10.2 Acceptance tests on components for an Approved Measuring System
77 10.3 Performance Test on Measuring Systems
10.4 Performance Check
10.5 IEC Standard Measuring Device
83 11 Measurement of impulse current
11.1 Requirements for an Approved Measuring System
11.2 Acceptance tests on components for an Approved Measuring System
11.3 Performance Test on Measuring Systems
11.4 Performance Check
12 Reference Measuring Systems 91
12.1 Requirements for Reference Measuring Systems
12.2 Calibration of a Reference Measuring System
12.3 Interval between successive Certifications of Reference
Measuring Systems 93
60-2 ©I EC:1994 — 7 —
Clause Page
Figures
Annexes
A Accreditation Systems
A.1 National accreditation systems
A.2 Bibliography
B Structure of a Record of Performance
B.1 General structure
B.2 General description of the system (Chapter A)
B.3 Acceptance test results on components (Chapter B)
B.4 Routine test results on the complete Measuring System (Chapter C)
B.5 Performance Test results (Chapter D)
B.6 Performance Check (Chapter E)
B.7 Minimal form of the Record of Performance
C Step response measurements
C.1 Circuits for step response measurements
D Temperature rise of measuring resistors
E Reference Measuring Systems and Comparison Measurements for
Impulse Measurements — Bibliography
E.1 Comparison measurements
E.2 Some examples of dividers for Reference Measuring Systems
E.3 IEC Standard Measuring Devices
F Summary of tests
121 F.1 Tests on a direct voltage Measuring System
F.2 Tests on an alternating voltage Measuring System
F.3 Tests on a lightning impulse Measuring System
FA Tests on a switching impulse Measuring System
F.5 Tests on an impulse current Measuring System
G Areas where special care is needed
G.1 Measurement of the scale factor of a divider
G.2 Probes and external attenuators
G.3 Probe scale factor
G.4 Use of appropriate levels
G.5 Accuracy of time measurements

60-2 © IEC:1994 - 9 -
INTERNATIONAL ELECTROTECHNICAL COMMISSION
HIGH-VOLTAGE TEST TECHNIQUES -
Part 2: Measuring Systems
FOREWORD
1) The IEC (International Electrotechnical Commission) is a worldwide organization for standardization
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.
3) They have the form of recommendations for international use published in the form of standards, technical
reports or guides and they are accepted by the National Committees in that sense.
4) In order to promote international unification, IEC National Committees undertake to apply IEC International
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.
5)
The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with one of its standards.
International Standard IEC 60-2 has been prepared by IEC technical committee 42: High-
voltage testing techniques.
This second edition cancels and replaces IEC 60-3, Measuring devices, published in 1976,
and IEC 60-4, Application guide for measuring devices, published in 1977. This second
edition constitutes a technical revision.
The text of this standard is based on the following documents:
Report on voting
DIS
42(CO)54 42(CO)57
Full information on the voting for the approval of this standard can be found in the report
on voting indicated in the above table.
IEC 60 consists of the following parts, under the general title: High-voltage test techniques:
-
Part 1: 1989, General definitions and test requirements
- Part 2: 1994: Measuring Systems
Annex A forms an integral part of this standard and provides normative requirements for
countries choosing to use accreditation systems.
Annexes B to G are for information only.

60-2 ©IEC:1994 - 11 -
HIGH-VOLTAGE TEST
TECHNIQUES -
Part 2: Measuring Systems
1 Scope
This part of IEC 60 is applicable to complete Measuring Systems, and to their components,
used for the measurement of high-voltages and currents during tests with direct voltage,
alternating voltage, lightning and switching impulse voltages and for tests with impulse
currents, or with combinations of them as specified in IEC 60-1.
The limits on measurement uncertainties stated in this International Standard apply to test
levels stated in IEC 71-1. The principles of this International Standard apply also to higher
levels but the uncertainty may be greater.
This standard:
- defines the terms used,
- states the requirements which the Measuring Systems shall meet,
-
describes the methods for approving a Measuring System and checking its components,
-
describes the procedure by which the user will show that a Measuring System
meets the requirements of this standard.

60-2 © IEC:1994 - 13 -
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of
this part of IEC 60. At the time of publication, the editions
indicated were valid. All normative documents are subject to revision, and pa
rties to
agreements based on this pa rt
of IEC 60 are encouraged to investigate the possibility of
applying the most recent editions of the normative documents indicated below. Members
of
IEC and ISO maintain registers of currently valid International Standards.
IEC 50(301, 302, 303): 1983, International Electrotechnical Vocabulary (IEV) - Chapter 301:
General terms on measurements in electricity; Chapter 302: Electrical measuring
instruments; Chapter 303: Electronic measuring instruments
IEC 50(321): 1986,
International Electrotechnical Vocabulary (lEV) - Chapter 321:
Instrument transformers
IEC 51, Direct acting indicating analogue electrical-measuring instruments and their
accessories
IEC 52: 1960,
Recommendations for voltage measurement by means of sphere-gaps (one
sphere earthed)
IEC 60-1: 1989, High-voltage test techniques - Pa rt
1: General definitions and test
requirements
IEC 71-1: 1993, Insulation co-ordination - Part 1: Definitions, principles and rules
IEC 790: 1984, Oscilloscopes and peak voltmeters for impulse tests
IEC 833: 1987,
Measurement of power-frequency electric fields
IEC 1083-1: 1991, Digital recorders for measurements in high-voltage impulse tests -
Part 1: Requirements for digital recorders

60-2 © IEC:1994 - 15 -
3 Definitions and symbols
For the purposes of this pa rt of IEC 60, the following apply.
3.1 Measuring Systems
3.1.1
Measuring System: Complete set of devices suitable for performing a high-voltage
or impulse-current measurement.
NOTES
1 A Measuring System usually comprises the following components: a converting device with the leads
required for connecting this device to the test object or into the current circuit and the connections to earth, a
transmission system connecting the output terminals of the device to the indicating or recording instruments
with its attenuating, terminating and adapting impedances or networks, and indicating or recording instru-
ments together with any connections to the power supply. Measuring Systems which comprise only some of
the above components or which are based on non-conventional principles are acceptable if they meet the
accuracy requirements specified in this standard. Components may be made of many elements or a single
element, for example, a high-voltage capacitor of a capacitor divider may consist of many low-voltage
capacitors or it may consist of a single gas capacitor.
2 The environment in which a Measuring System functions, its clearances to live and earthed structures and
the presence of electric or magnetic fields may significantly affect its accuracy.
3.1.2 Record of Performance of a Measuring System: Detailed record, established by
the user, describing the system and containing evidence that the requirements given
in this standard have been met. This evidence shall include the results of the initial
rf rformance Test and
Pe ormance Test and the schedule and results of each subsequent Pe
Pe rformance Check.
3.1.3 Approved Measuring System: Measuring System which is shown to comply with
one or more of the sets of requirements set out in this standard by:
- an initial Performance Test,
- successive Pe rformance Checks and Pe rformance Tests,
- ormance.
inclusion of the results of these tests in the Record of Pe rf
The system is approved only for the arrangements and operating conditions included in its
Record of Pe
rformance.
3.1.4 Reference Measuring System: Measuring System having sufficient accuracy and
stability for use in the approval of other systems by making simultaneous comparative
measurements with specific types of waveform and ranges of voltage or current.
NOTE — A Reference Measuring System (maintained according to the requirements of this standard) can be
used as an Approved Measuring System but the converse is not true.
3.1.5 IEC Standard Measuring
Device: Device that can be used for measuring high-
voltage with the specified accuracy (for example a sphere-gap or a rod/rod gap used
according to IEC 60-1).
60-2 ©IEC:1994 -17 -
3.2 Converting devices
3.2.1 converting device: Device for converting the quantity to be measured into another
quantity, compatible with the indicating or recording instrument.
3.2.2 voltage divider: Converting device consisting of a high-voltage and a low-voltage
arm such that the input voltage is applied across the complete device and the output
voltage is taken from the low-voltage arm. [IEV 301-05-13, modified]
NOTE — The elements of the two arms are usually resistors or capacitors or combinations of these and the
device is described by the type and arrangement of its elements (for example, resistor, capacitor or resistor-
capacitor).
3.2.3 voltage transformer: Step-down transformer for the measurement of the para-
meters of high alternating voltages. [IEV 321-03-01, modified]
which carries
3.2.4 high-voltage measuring impedance: Device a current proportional
to the applied voltage.
3.2.5 current-measuring shunt: Resistor across which the voltage is proportional to the
current to be measured. [IEV 301-06-05, modified]
3.2.6 compensated current-measuring device: Current-measuring device which
includes a compensating circuit.
3.2.7 current transformer: Transformer which produces an output proportional to the
input current. [IEV 321-02-01, modified]
NOTE — A Rogowski coil used with an integrating circuit is a wide-band current transformer.
3.2.8 electric-field probe: Converting device for the measurement of the amplitude and
waveform of an electric field.
NOTE — An electric-field probe may be used to measure the waveform of the voltage producing the field
provided that the measurement is not affected by corona.
3.3 transmission system: Set of devices which transfers the output signal of a convert-
ing device to an indicating and/or recording instrument.
NOTES
1 A transmission system generally consists of a coaxial cable with its terminating impedance, but it may
include attenuators or other devices connected between the converting device and the instrument. For example,
an optical link includes the transmitter, the optical cable and the receiver as well as related amplifiers.
2 A transmission system may be partially or completely included in the converting device.
3.4 indicating or recording instrument: Device intended to display or provide
a record
of the value of
a measurand or a related value. [IEV 301-02-11 and 12, modified]

60-2 © IEC:1994 - 19 -
3.5 Scale factors
3.5.1 scale factor of a Measuring System:
Factor by which the value of the instrument
reading is to be multiplied to obtain the value of the input quantity.
NOTES
1 A Measuring System may have more than one scale factor, for example, it may have different scale
factors for different frequency ranges or waveforms (see 3.6.1).
2 For some Measuring Systems the value of the input quantity is displayed directly (i.e., the scale factor of
the Measuring System is unity).
3.5.2 scale factor of a converting device: Factor by which the output of the converting
device is to be multiplied to obtain its input quantity.
NOTE – The scale factor of a converting device may be dimensionless (for example, the ratio of a divider)
or may have dimensions (for example, the impedance of a high-voltage measuring impedance).
3.5.3 scale factor of a transmission system:
Factor by which the output of a
transmission system is to be multiplied to obtain its input quantity.
3.5.4 scale factor of an indicating or recording instrument: Factor by which the
instrument reading is to be multiplied to obtain its input quantity.
3.5.5 Assigned Scale Factor:
Scale factor of a Measuring System determined at the
most recent Performance Test.
NOTE – A Measuring System may have more than one Assigned Scale Factor, for example, it may have
several Nominal Epochs each with a different value (see 3.6.1)
3.6 Definitions related to the dynamic behaviour of a Measuring System
3.6.1 Nominal Epoch
't N (Impulse measurements, front part of impulse only): Range of
values between the minimum and the maximum of the relevant time parameter
(tmin) (tmax)
of impulses for which the Measuring System is to be approved. The relevant time para-
meter is:
the front time T1 for full lightning and tail-chopped impulses and for current
impulses
the time to chopping Tc for front-chopped impulses
the time to peak Tp for switching impulses
NOTES
1 A Measuring System may have one, two or more Nominal Epochs for different waveforms. For example, a
particular Measuring System might be approved:
–
for full lightning impulses with an Assigned Scale Factor F, over a Nominal Epoch from T1 =
TN1
0,8 µs to T1 = 1,2 µs
–
for front-chopped lightning impulses with an Assigned Scale Factor F2 over a Nominal Epoch
TN2
from Tc = 0,5 p.s to c = 0,9 µs
- for switching impulses with an Assigned Scale Factor F3 over a Nominal Epoch TN3 from Tp =
200 µs to Tp = 300 µs.
2 "Front-chopped impulse" is used to designate a chopped impulse with a time to chopping in the range
0,5 .ts to 2 µs as distinct from a "tail-chopped impulse" which has a time to chopping greater than 2 µs.

60-2 ©IEC:1994 - 21 -
3.6.2 response of a Measuring System G: Output, as a function of time or frequency,
when a specified voltage or current is applied to the input of the system.
3.6.3 amplitude/frequency response G(t): Ratio of the output to the input of a Measuring
System as a function of frequency f, when the input is sinusoidal (see figure 1).
3.6.4 Output of a Measuring System as a function of time when the
step response G(t):
input is a step function.
3.7 Response parameters
3.7.1
response parameters: Parameters which are derived from the measured amplitude/
frequency response or the measured step response by applying the specified procedure.
3.7.2 : Lower and upper limits of the range within which the
limit frequencies f1 and f2
amplitude/frequency response is nearly constant. These limits are where the response first
deviates by ±3 dB from the constant value (see figure 1).
3.7.3 Reference Level /R (impulse measurements only): Mean value of the step
response taken over a Nominal Epoch (see figure 2).
NOTE - A Measuring System may have more than one Reference Level, for example, it may have different
scale factors for different waveforms (see 3.6.1 and figure 2).
3.7.4
virtual origin of a step response 0 1 : Intersection with the time axis of a straight
line drawn as a tangent to the steepest portion of the front of the step response. In the
case of a response with oscillations on the front, a mean curve is drawn through the oscil-
lations and used to determine the tangent line. Any initial distortion is neglected when
drawing the tangent line (see figure 3a).
NOTES
1 All time values are measured from the virtual origin 01.
2 For a smooth response, or for a smooth curve drawn through oscillations, the steepest portion will occur
near the beginning of the response.
3.7.5 normalized step response g(t): Step response normalized such that a Reference
Level becomes unity.
NOTE - A Measuring System has a normalized step response for each Reference Level.
3.7.6
step response integral T(t): Integral from 0 1 to t of one minus the normalized
step response g(t), but with the initial po rtion of g(t) replaced by the straight line drawn to
determine 01
(see 3.7.4).
ti
T(t) = f (1 - g(ti)) dz
60-2 ©IEC:1994 - 23 -
3.7.7 TN:
experimental response time Value of the step response integral at
tmax
(see 3.6.1):
TN =
T(tmax)
3.7.8 partial response time T : Maximum value of the step response integral (see figure 3b).
Œ
NOTE — Usually Ta = T(t1 ) where t1 is the time when g(t) first reaches unit amplitude.
3.7.9 residual response time TR(ti): Experimental response time minus the value of the
step response integral at some specific time ti where ti < tmax.
TR( ti) = TN - T(ti)
3.7.10 overshoot f3: Amount by which the maximum value of the normalized step
response g(t) exceeds unity.
3.7.11
initial distortion time To: Area bounded by the zero line, the normalized step
response g(t) and the straight line used to determine 01 (see figure 3a).
3.7.12 settling time t Shortest time for which the residual response time TR(t)
s:
becomes and remains less than 2 % of t:
TN — T(t) I <0,02 is
for all values of t in the epoch from is to t (see figure 3b).
max
3.7.13 Equivalent Time TE : Time parameter of calibration waveforms that:
-
for direct voltage TE is equal to 100 ms (arbitrary),
- for alternating voltage TE is equal to one quarter of the period,
- for impulses TE p (for lightning impulses, use definition
is equal to the time to peak T
of T for switching impulses).
3.8
overall uncertainty e: Estimate characterizing the range of values around the result
of a measurement within which the true value of the measurand could lie; it is the combi-
nation of many individual uncertainties due to the presence of many influence quantities.
NOTE — It is assumed that most of the sources of uncertainty considered in this standard have a random
character and can be regarded as independent; the preferred estimate for the overall uncertainty e is:
e=
where e and each e are expressed at the same confidence level.

60-2 ©
IEC:1994 - 25 -
3.9 Rated values
3.9.1 Rated Measuring Voltage or Rated Measuring Current: Maximum level of
voltage or current of specified frequency or waveform at which a Measuring System can
be used within the uncertainty limits given in this pa rt of IEC 60.
3.9.2 operating voltage or current range: Range of voltage or current of specified
frequency or waveform in which a Measuring System can be used within the uncertainty
limits given in this part of IEC 60.
NOTE — The limits of the operating range are chosen by the user and verified by the Performance Tests
specified in this part of IEC 60.
3.9.3 operating time (for direct or alternating voltages): Time during which the
Measuring System can operate at its Rated Measuring Voltage within the uncertainty limits
given in this part of IEC 60.
3.9.4
maximum rate of application (for impulses): Maximum rate of application
of impulses with a specified waveform, at which the Measuring System can operate
within the uncertainty limits given in this pa rt of IEC 60 for a specified time at its Rated
Measuring Voltage or Rated Measuring Current.
3.10
Definitions related to tests
3.10.1 acceptance test: Test on a device or Measuring System before it is accepted for
use. The acceptance test includes type tests (performed on a device of the same design)
and routine tests (performed on every device) to assess its specific characteristics, for
example, measurement of temperature coefficient of an element, withstand test, etc. In
rf
addition, the acceptance test on a Measuring System includes the first Pe ormance Test.
3.10.2 Performance Test: Test on a complete Measuring System to characterize it
under operating conditions.
3.10.3 Performance Check:
Simple procedure to ensure that the most recent Perform-
ance Test is still valid.
3.10.4 Reference Record (impulses measurements only): Record taken under spe-
cified conditions in a Pe rformance Test and retained for comparison with records to be
taken in future tests or checks under the same conditions (see 9.3.2, 10.3.2, and 11.3.2).

60-2 © IEC:1994 – 27 –
4 Procedures for qualification and use of Measuring Systems
4.1 General principles
Approved Measuring Systems are required to undergo acceptance tests followed by tests
and checks throughout their se rvice lives.
The following are usually necessary:
– acceptance tests on system components (required once only),
– Performance Tests on the system (periodic, see 4.2),
– Performance Checks on the system (periodic, see 4.3).
A major requirement for converting devices, transmission systems and measuring ins-
truments used in Measuring Systems is stability within their specified range of operating
conditions so that the scale factor of the Measuring System remains constant over long
periods.
ormance Tests.
The scale factor is determined in the Pe rf
Test facilities shall use the tests given in this part of IEC 60 to qualify their Measuring
System(s). Alternatively, any test facility may choose to have the Pe rformance Tests made
by a National Laboratory or by an Accredited Calibration Laboratory: in this case the
period of validity of each calibration is set by the National Laboratory or by the Accrediting
Body.
Countries which choose to employ accreditation procedures to provide certified traceability
in the implementation of this standard, shall meet the requirements given in annex A.
Annex A is not applicable to the countries which do not choose to employ accreditation
procedures.
Tables summarizing the tests to be performed on each type of Measuring System are
given in annex F.
4.2 Schedule of Performance Tests
To maintain the quality of a Measuring System its Assigned Scale Factor(s) shall be deter-
ormance Tests of clause 6 repeated periodically: it is recommended that
mined by the Pe rf
the tests of clause 6 should be repeated annually and in any case it shall be repeated at
least once every five years.
Pe rformance Tests shall be made after major repairs to the Measuring System and
whenever a circuit arrangement which is beyond the limits already given in the Record of
Pe rf
ormance is to be used.
When Pe ormance Tests are required because a Pe rformance Check shows that the
rf
Assigned Scale Factor has changed significantly, the cause of this change shall be
investigated before the Performance Tests are made.

60-2 © IEC:1994 – 29 –
4.3
Schedule of Performance Checks
Pe rformance Checks shall be made at intervals based on the recorded stability of the
Measuring System as shown in the Record of Pe rformance.
Initially Pe rformance Checks shall be made at short intervals to determine this stability.
Performance Checks are described in 7.4, 8.4, 9.4, 10.4, and 11.4.
No reference method is identified for the Pe rformance Checks because the required accu-
racy is less than that required for Pe rformance Tests: users requiring higher accuracies
should repeat the Performance Test more frequently.
4.4
Requirements for the Record of Performance
4.4.1
Contents of the Record of Pe rformance
The results of all tests and checks with the conditions under which the results were
obtained shall be kept in the Record of Performance established and maintained by
the user.
An outline of the Record of Performance is given in 4.4.3, the full format of the recom-
mended Record of Pe rformance is given in annex B (informative), clauses B.1 to B.6 and a
minimal form is given in clause B.7.
4.4.2 Exceptions
In the case of apparatus or equipment manufactured before the date of issue of this standard,
if the evidence required in some of the acceptance tests (for example, 5.6 and 5.9) is not
available, then Performance Tests (in accordance with clause 6) and checks made in
accordance with earlier standards are deemed to be adequate provided they show the
scale factor is stable. The results of these previous checks shall also be entered in the
Record of Pe rformance.
Approved Measuring Systems comprising several pieces of equipment used interchange-
ably, may be covered by a single Record of Performance including ail the combinations
possible with the least amount of duplication possible. Specifically, each converting device
shall be covered individually, but .transmission systems and instruments may be covered
generically so that a range of cable lengths or similar instruments which meet the require-
ments of the relevant IEC standard may be indicated.
4.4.3 Outline of a Record of Performance
rf
It is recommended that the format of each Record of Pe ormance be as follows:
Chapters A: General descriptions of the Measuring System (see clause B.2)
Chapter B: Results of acceptance tests on converting devices, transmission systems
and measuring instruments (see clause B.3)

60-2 © IEC:1994 - 31 -
Chapter C: Results of routine tests on the Measuring System, when performed (see
clause B.4)
Chapters D: Results of Performance Tests on the Measuring System (see clause B.5)
Chapters E: Results of Performance Checks on the Measuring System (see clause B.6)
The successive chapters are identified by an ordinal number when needed (for example,
Chapter Al is the first general description of the system, Chapter A2 the description of the
system after the first significant change, etc., Chapter D1 the initial Performance Test of
the system, Chapter D2 the second one, etc. but Chapter B and Chapter C will not need
repetition). For details see annex B.
The Assigned Scale Factor to be used shall be the one determined at the latest Perform-
ance Test and shall be filed under the latest Chapters D.
4.5 Operating conditions
An Approved Measuring System for voltages shall be connected directly to the terminals of
the test object. The parasitic coupling between the test and measuring circuits should be
minimized.
An Approved Measuring System for currents shall be connected in series with the test
object.
An Approved Measuring System is usually designed for operating within the required limits
of uncertainty in dry service conditions and in the absence of pollution.
Unless otherwise specified, Measuring Systems for direct and alternating voltages shall be
designed for continuous operation.
Unless otherwise specified, the maximum rate of application for Measuring Systems for
impulses shall be two per minute.

60-2 © IEC:1994 - 33 -
5 Acceptance tests on components for an Approved Measuring System
5.1 Applicability
The tests described in this clause are required for components of Measuring Systems.
However these tests are not required for transmission systems which consist only of cables
nor for instruments which meet the requirements of the relevant standard referenced in
clause 2. Some of these tests cannot be performed on existing equipment (see 5.6 and 5.9):
for these cases see 4.4.2.
For some of the tests described in this clause it is necessary to include the component in
an appropriate Measuring System (whose other components have been shown to be
linear), for example, the linearity test of 5.3.
5.2 Determination of the scale factor
The determination of the scale factor of a component may be made by one of the following
methods:
- simultaneous measurements of its input and output quantities,
- a bridge method,
- calculation based on measured impedances.
The scale factor of a current-measuring shunt shall be measured by direct current
methods.
5.3 Linearity test
Values of the scale factor of the Measuring System shall be measured at the minimum and
maximum voltages (or currents) of the operating range and at three approximately equally
spaced voltages or currents between these extremes. These five values shall not differ by
more than ±1 % from their mean value.
The reference method is by comparison with a Reference Measuring System according
to 6.2 a).
Alternative methods are:
either comparison with an Approved Measuring System, the linearity of which has been
established by the reference method
or one of the additional methods described in the relevant clauses of this standard.
These additional methods are provided to allow users alternative tests which may be
economic. However, failure to meet the requirements of these tests does not necessarily
show that a Measuring System is non-linear.
In such a case either the reference method or the method of comparison with an Approved
Measuring System shall be used.

60-2 © IEC:1994 – 35 –
5.4
Short-term stability test
The full rated voltage or current shall be applied to the device continuously (or in the case
of impulses, at the maximum rate) for a period appropriate to the anticipated use.
The scale factor shall be measured before and immediately after (within 10 min) the appli-
cation of the voltage or current. The two values shall not differ by more than 1 %.
5.5 Long-term stability of single elements
The stability characteristics, voltage and current effects and temperature effects of each
type of element, shall be such that the scale factor of a converting device does not change
by more than 1 % between successive Pe rformance Tests.
These characteristics may be taken from manufacturer's data or demonstrated by successive
Performance Tests.
5.6 Temperature effect
The variations of the scale factor or of a parameter (for example, resistance or capacitance)
of a device due to changes of the ambient temperature are determined by computation
using the temperature coefficients of single elements or by making measurements at different
temperatures.
The temperature coefficients shall be listed in the Record of Pe rformance and may be
taken from manufacturer's data.
Temperature correction factors may be used in cases where the ambient temperature
varies over a wide range. Any temperature corrections to be used shall be listed in the
Record of Pe rformance.
In each case, it shall be shown that the scale factor is within 1 %, taking into account any
temperature correction (see annex D).
5.7 Proximity effect
Variations of the scale factor or of a parameter of a device, due to proximity effects,
can be determined by measurements performed for different distances of the device
from an earthed wall or an energized structure, the distances from other earthed walls or
energized structures remaining constant or so large there is no effect.
For each range of distances listed in the Record of Pe rf
ormance, it shall be shown that the
scale factor is within 1 %.
For current measurements, the effects of off-centre paths (when relevant) and the effects
of nearby paths for high currents can be determined by measurements performed for different
paths and distances to current-carrying conductors.
NOTE - Some test facilities may chose to approve their Measuring Systems for only a single set of
distances, or for a few sets or ranges of distances.

60-2 © - 37 -
IEC:1994
5.8
Dynamic behaviour of a component
The response of the component shall be determined in a Measuring System representative
of its operating conditions, particularly clearances to earthed and energized structures.
Either the amplitude/frequency response or the step response shall be measured.
5.8.1 Determination of the amplitude/frequency response
The system is subjected to a sinusoidal input of known amplitude, usually at low level,
and the output is measured. This measurement is repeated for an appropriate range of
frequencies.
5.8.2 Determination of the step response
The system is subjected to a voltage or current step and its output is measured (see
annex C). The rise time of the applied step should be less than 1/10 of the pa rtial response
time TŒ.
5.9 Withstand tests
A converting device shall pass a d ry withstand test performed with a voltage or current of
the required frequency or shape at a level of 110 % of the Rated Measuring Voltage or
Rated Measuring Current. For the procedures of withstand tests see IEC 60-1.
Wet tests and pollution tests, when specified, are performed as type tests.
The withstand tests shall be performed at the polarity or polarities at which the system is
to be used.
NOTE — Design and construction of any component of an Approved Measuring System should be such that
it can withstand a disruptive discharge at the test object without any change in its characteristics.

60-2 © IEC:1994 – 39 –
6 Performance Tests on Measuring Systems
6.1
General requirements
The Assigned Scale Factor of the Measuring System is determined by calibration using the
specified Pe rf
ormance Tests. For an Impulse Measuring System, the Pe rformance Tests
also show that its dynamic pe rformance is adequate for the specified measurements and
that the level of any disturbance is less than the specified limits.
In high-voltage tests, the size of the apparatus, the levels of voltage and current used, and
the interaction between the test and measuring circuits often make it necessary to perform
calibration tests in the test facility of the user.
However, Measuring Systems or their components may be transported to another labo-
ratory for calibration in an arrangement which simulates the operating conditions, provided
that the interference test, when specified, is performed in the test facility of the user. The
simulated arrangement shall represent the operating conditions described in the Record
of Perf
ormance and this simulated arrangement shall also be described in the Record of
Perf
ormance.
Unless type tests show a converting device is not sensitive to proximity effects over a
specified range of clearances the Assigned Scale Factor of any Measuring System based
on that converting device shall be measured for each condition of use. Each set of clear-
ances or range of clearances shall be entered in the Record of Pe rf
ormance.
The input voltage or current used for calibration should be of the same type, frequency or
waveform as voltages or currents to be measured. When this condition is not fulfilled,
evidence shall be given of the validity of the Assigned Scale Factor in the range of
frequency or waveforms to be used.
The reference method of determining the Assigned Scale Factor is comparison with a
Reference Measuring System at the Rated Measuring Voltage or Rated Measuring Current
whenever possible. However, as Reference Measuring Systems are not always available
at the highest voltages and currents, the comparison may be made at voltages or currents
as low as 20 % of the Rated Measuring Voltage or Rated Measuring Current (see 6.2 a)).
For lightning impulses with peak values over 1 MV, it may be made at 200 kV. Alter-
natively, the Assigned Scale Factor may be determined by measuring the scale factor of
each component, usually at low voltage, and taking the product of the scale factors of the
components (see 6.2 b)).
The voltage or current used to determine the Assigned Scale Factor shall be included in
the range covered by the linearity test.
All equipment used in establishing the scale factors of Measuring Systems and all instru-
ments used in Measuring Systems shall have calibrations traceable to National Measurement
Standards (Etalons).
The conditions under which the calibration has been performed shall be included in the
Record of Pe
rformance.
60-2 ©IEC:1994 - 41 -
6.2 Determination of the Assigned Scale Factor
a) Reference method: comparison with a Reference Measuring System
A Reference Measuring System shall be connected in parallel (voltage) or in series
(current) with the Measuring System to be calibrated. Simultaneous readings shall be
taken on both systems; the value of the input quantity obtained for each measurement
by the Reference Measuring System is divided by the corresponding reading of the
instrument in the system under test to obtain a value F
i of its scale factor. The pro-
cedure is repeated to obtain n independent readings (n >_ 10) and the mean value Fm
is taken as the Assigned Scale Factor of the system under test, provided that the
experimental standard deviation s as calculated from:
E
(F -Fm)2
s-
n-1
is less than 1 % of Fm.
NOTES
1 A rounded value F
0 may be taken as the Assigned Scale Factor if, introduced in place of F m in the formula
for s, it gives the value of s less than 1 % of Fm.
2 For measurement of direct and alternating voltages, independent readings may be obtained either by
applying the test voltage and taking n readings or by applying the test voltage n times and taking a reading
each time. For impulses, n impulses are applied.
The test shall be performed at a single voltage or current level (see 6.1). The setting of
the measuring instrument may be changed or a different instrument may be used to
achieve a suitable sensitivity, provided that this change does not alter the rest of the
Measuring System and that the settings used on each instrument have been calibrated.
If only one measuring instrument is available (this measuring instrument is the instrument
to be used in the Approved Measuring System and shall meet the relevant IEC standard)
the test may be made by the repeated alternate connection of the instrument to each
system to provide the n i
values F . A termination equivalent to the instrument shall
be connected in the place of the instrument in the other system. All other pa rts of both
systems shall remain unchanged.
A Measuring System with several scale factors (for example, the use of different low-
voltage arms for a voltage divider) shall be calibrated for each scale factor. Measuring
Systems with secondary voltage dividers may be calibra
...