ETSI ETR 273-1-1 ed.1 (1998-02)

ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Improvement of radiated methods of measurement (using test sites) and evaluation of the corresponding measurement uncertainties; Part 1: Uncertainties in the measuremement of mobile radio equipment characteristics; Sub-part 1: Introduction

DTR/ERM-RP01-018-1-1

Elektromagnetna združljivost (EMC) in zadeve v zvezi z radijskim spektrom (ERM) - Izboljšanje zvezdastih merilnih metod (z uporabo merilnih mest) in ovrednotenje ustreznih merilnih negotovosti - 1. del: Netočnosti pri merjenju karakteristik mobilnih radijskih naprav - 1. podpoglavje: Uvod

General Information

• Status: Published
• Publication Date: 25-Feb-1998
• Technical Committee: ERM RP01 - Maritime Radio
• Current Stage: 13 - TB decision to make document historical
• Completion Date: 17-Jun-2005
• Mandate: T-042-SI
• Ref Project: PSIST ETR 273-1-1:1999 - ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Improvement of radiated methods of measurement (using test sites) and evaluation of the corresponding measurement uncertainties; Part 1: Uncertainties in the measuremement of mobile radio equipment characteristics; Sub-part 1: Introduction

Standards Content (Sample)

SLOVENSKI STANDARD
01-april-1999
(OHNWURPDJQHWQD]GUXåOMLYRVW(0&LQ]DGHYHY]YH]L]UDGLMVNLPVSHNWURP(50
,]EROMãDQMH]YH]GDVWLKPHULOQLKPHWRG]XSRUDERPHULOQLKPHVWLQRYUHGQRWHQMH
XVWUH]QLKPHULOQLKQHJRWRYRVWLGHO1HWRþQRVWLSULPHUMHQMXNDUDNWHULVWLN
PRELOQLKUDGLMVNLKQDSUDYSRGSRJODYMH8YRG
ElectroMagnetic Compatibility and Radio Spectrum Matters (ERM); Improvement of
radiated methods of measurement (using test sites) and evaluation of the corresponding
measurement uncertainties; Part 1: Uncertainties in the measuremement of mobile radio
equipment characteristics; Sub-part 1: Introduction
Ta slovenski standard je istoveten z: ETR 273-1-1 Edition 1
ICS:
33.060.01 Radijske komunikacije na Radiocommunications in
splošno general
33.100.01 Elektromagnetna združljivost Electromagnetic compatibility
na splošno in general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

ETSI ETR 273-1-1
TECHNICAL February 1998
REPORT
Source: ERM Reference: DTR/ERM-RP01-018-1-1
ICS: 33.020
Key words: Analogue, data, measurement uncertainty, mobile, radio, testing
Electromagnetic compatibility
and Radio spectrum Matters (ERM);
Improvement of radiated methods of
measurement (using test sites) and
evaluation of the corresponding
measurement uncertainties;
Part 1: Uncertainties in the measurement
of mobile radio equipment characteristics;
Sub-part 1: Introduction
ETSI
European Telecommunications Standards Institute
ETSI Secretariat
Postal address: F-06921 Sophia-Antipolis CEDEX - FRANCE
Office address: 650 Route des Lucioles - Sophia Antipolis - Valbonne - FRANCE
X.400: c=fr, a=atlas, p=etsi, s=secretariat - Internet: [e-mail]
Tel.: [phone] - Fax: [phone]
Copyright Notification: No part may be reproduced except as authorized by written permission. The copyright and the
foregoing restriction extend to reproduction in all media.
© European Telecommunications Standards Institute 1998. All rights reserved.

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ETR 273-1-1: February 1998
Whilst every care has been taken in the preparation and publication of this document, errors in content,
typographical or otherwise, may occur. If you have comments concerning its accuracy, please write to
"ETSI Editing and Committee Support Dept." at the address shown on the title page.

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ETR 273-1-1: February 1998
Contents
Foreword .9
Introduction.9
1 Scope.11
2 References .11
3 Definitions, symbols and abbreviations .12
3.1 Definitions.12
3.2 Symbols .16
3.3 Abbreviations .18
4 Introduction to measurement uncertainty.19
4.1 Background to measurement uncertainty.19
4.1.1 Commonly used terms .19
4.1.2 Assessment of upper and lower uncertainty bounds .20
4.1.3 Combination of rectangular distributions.21
4.1.4 Main contributors to uncertainty .23
4.1.5 Other contributors.23
4.2 Evaluation of individual uncertainty components.24
4.2.1 Evaluation of type A uncertainties.24
4.2.2 Evaluation of type B uncertainties.25
4.2.3 Influence quantity uncertainties .26
4.3 Methods of evaluation of overall measurement uncertainty.26
4.4 Summary.27
4.5 Overview of the approach of this ETR.27
5 Analysis of measurement uncertainty.27
5.1 The BIPM method .28
5.1.1 Type A uncertainties and their evaluation.28
5.1.2 Type B uncertainties and their evaluation.28
5.2 Combining individual standard uncertainties in different units.29
5.3 Calculation of the expanded uncertainty limits (Student's t-distribution).31
5.4 Combining standard uncertainties of different parameters, where their influence on each
other is dependant on the EUT (influence quantities).31
5.5 Estimate of standard uncertainty of randomness.32
5.6 Summary of the recommended approach .34
6 Examples of uncertainty calculations specific to radio equipment .34
6.1 Mismatch.34
6.2 Attenuation measurement.35
6.3 Calculation involving a dependency function .37
6.4 Measurement of carrier power .39
6.4.1 Measurement set-up.39
6.4.2 Method of measurement .39
6.4.3 Power meter and sensor module .39
6.4.4 Attenuator and cabling network.40
6.4.4.1 Reference measurement .41
6.4.4.2 The cable and the 10 dB power attenuator.42
6.4.4.3 The 20 dB attenuator .43
6.4.4.4 Instrumentation.44
6.4.4.5 Power and temperature influences .45
6.4.4.6 Collecting terms.45

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ETR 273-1-1: February 1998
6.4.5 Mismatch during measurement.45
6.4.6 Influence quantities .46
6.4.7 Random.47
6.4.8 Expanded uncertainty.47
6.5 Uncertainty calculation for measurement of a receiver (Third order intermodulation).48
6.5.1 Noise behaviour in different receiver configurations.48
6.5.3 Interference immunity measurements .50
6.5.4 Blocking and spurious response measurements.50
6.5.5 Third order intermodulation.50
6.5.5.1 Measurement of third order intermodulation.51
6.5.5.2 Uncertainties involved in the measurement.52
6.5.5.2.1 Signal level uncertainty of the two
unwanted signals .52
6.5.5.2.2 Signal level uncertainty of the wanted
signal.53
6.5.5.3 Analogue speech (SINAD) measurement uncertainty.53
6.5.5.4 BER and message acceptance measurement uncertainty.53
6.5.5.5 Other methods of measuring third order intermodulation.54
6.6 Uncertainty in measuring continuous bit streams.54
6.6.1 General.54
6.6.2 Statistics involved in the measurement.54
6.6.3 Calculation of uncertainty limits when the distribution characterizing the
combined standard uncertainty cannot be assumed to be a Normal
distribution.56
6.6.4 BER dependency functions.58
6.6.4.1 Coherent data communications.59
6.6.4.2 Coherent data communications (direct modulation) .59
6.6.4.3 Coherent data communications (subcarrier modulation).60
6.6.4.4 Non coherent data communication .61
6.6.4.5 Non coherent data communications (direct modulation) .61
6.6.4.6 Non coherent data communications (subcarrier
modulation).63
6.6.5 Effect of BER on the RF level uncertainty .64
6.6.5.1 BER at a specified RF level .64
6.7 Uncertainty in measuring messages .67
6.7.1 General.67
6.7.2 Statistics involved in the measurement.67
6.7.3 Analysis of the situation where the up down method results in a shift
between two levels .68
6.7.4 Detailed example of uncertainty in measuring messages.69
7 Theory of test sites.72
7.1 Introduction.72
7.1.1 Basic concepts.72
7.2 Radiated fields .72
7.2.1 Fields radiated by an isotropic radiator.72
7.2.2 Directivity implications on the ideal radiator.73
7.2.3 The nature of the fields around a source of finite size.73
7.2.3.1 Derivation of the far-field distance (2d /l)).76
7.2.4 Reception in the far-field (2(d + d ) /G)).77
1 2
7.2.5 Choice of physical antenna for the "ideal" model.79
7.3 Ideal radiating sources.79
7.3.1 Electric current element.79
7.3.2 Magnetic current element .80
7.4 Theoretical analysis of the dipole .81
7.5 Model of the ideal test site .82
7.6 Ideal practical test sites .83
7.6.1 Anechoic chamber .83
7.6.2 Anechoic chamber with a ground plane.86
7.6.3 Open area test site.91

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ETR 273-1-1: February 1998
7.6.4 Striplines.92
7.7 Verification.93
7.7.1 Introduction.93
7.7.1.1 Anechoic chamber.95
7.7.1.2 Anechoic chamber with a ground plane and open area test
site .96
max max
7.7.1.3 Improvements to the formulae for E and E .99
DH DV
7.7.1.4 Mutual coupling.100
7.8 The nature of the testing field on free field test sites.102
7.8.1 Fields in an anechoic chamber.102
7.8.1.1 Practical uniform field testing .103
7.8.1.2 Sensitivity considerations.104
7.8.1.3 Appreciable size source.104
7.8.1.4 Minimum separation distance.105
7.8.1.5 Summary.105
7.8.2 Fields over a ground plane .106
8 Practical test sites .108
8.1 Introduction.108
8.1.1 Test types.108
8.2 Test sites.109
8.2.1 Description of an anechoic chamber.109
8.2.2 Description of an anechoic chamber with a ground plane .111
8.2.3 Description of an open area test site.112
8.2.4 Description of striplines.113
8.3 Facility components their effects.115
8.3.1 Effects of the metal shielding.115
8.3.1.1 Resonances .115
8.3.1.2 Imaging of antennas (or an EUT).116
8.3.2 Effects of the radio absorbing materials .116
8.3.2.1 Introduction .116
8.3.2.2 Pyramidal absorbers.117
8.3.2.3 Wedge absorbers .119
8.3.2.4 Ferrite tiles.119
8.3.2.5 Ferrite grids.120
8.3.2.6 Urethane/ferrite hybrids.120
8.3.2.7 Floor absorbers .120
8.3.2.8 Performance comparison.121
8.3.2.9 Reflection in an anechoic chamber.122
8.3.2.10 Reflections in an anechoic chamber with a ground plane .125
8.3.2.11 Mutual coupling due to imaging in the absorbing material.125
8.3.2.12 Extraneous reflections.125
8.3.3 Effects of the ground plane.126
8.3.3.1 Coatings.127
8.3.3.2 Reflections from the ground plane .127
8.3.3.3 Mutual coupling to the ground plane.129
8.3.4 Other effects.133
8.3.4.1 Range length and measurement distance.133
8.3.4.2 Minimum far-field distance .134
8.3.4.2.1 Measurment distances.134
8.3.4.3 Antenna mast, turntable and mounting fixtures.140
8.3.4.4 Test antenna height limitations .142
8.3.4.5 Test antenna cabling .142
8.3.4.6 EUT supply and control cabling .143
8.3.4.7 Positioning of the EUT and antennas.143
8.3.5 Effects of the stripline .144
8.3.5.1 Mutual coupling.144
8.3.5.2 Characteristic impedance of the line .145
8.3.5.3 Non-planar nature of the field distribution .145
8.3.5.4 Field strength measurement.145

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ETR 273-1-1: February 1998
8.3.5.5 Correction factor for the size of EUT.146
8.3.5.6 Influence of site effects.146
9 Constructional aspects.147
9.1 Introduction.147
9.2 Open area test site.148
9.2.1 Site surveys and site location.148
9.2.1.1 Detection system sensitivity .149
9.2.1.2 Site survey procedure.150
9.2.1.3 Example of a site survey.152
9.2.2 Extraneous reflections.153
9.3 Anechoic chamber (with and without a ground plane).155
9.3.1 Basic shielded enclosure parameters .155
9.3.2 Basic shielded enclosure resonances .156
9.3.3 Waveguide type propagation modes.156
9.3.4 Earthing arrangements.157
9.3.5 Skin depth.157
9.3.6 Shielding effectiveness.159
9.4 Striplines.162
9.4.1 Open 2-plate stripline test cell.162
9.5 Miscellaneous.163
9.5.1 Long term stability .163
9.5.2 Power supplies.165
9.5.3 Ancillary equipment.166
10 Test equipment.166
10.1 Introduction.166
10.2 Cables.167
10.2.1 Cable attenuation.168
10.2.2 Cable coupling.169
10.2.3 Cable shielding .170
10.2.4 Transfer impedance.170
10.2.5 Improving cable performance with ferrite beads .174
10.2.5.1 Impedance .174
10.2.6 Equipment interconnection (mismatch).176
10.3 Signal generator.177
10.4 Attenuators .178
10.4.1 Attenuators used in test site verification procedures .178
10.4.2 Attenuators used in test methods.178
10.4.3 Other insertion losses .178
10.5 Antennas.179
10.5.1 Antenna factor.179
10.5.2 Gain .180
10.5.3 Tuning.180
10.5.4 Polarization .181
10.5.5 Phase centre.181
10.5.6 Input impedance .182
10.5.7 Temperature .182
10.5.8 Nearfield .182
10.5.9 Farfield .182
10.5.10 Non-uniform field pattern .182
10.5.11 Mutual coupling to the surroundings.184
10.6 Spectrum analyser and measuring receiver.184
10.6.1 Detector characteristics .186
10.6.2 Measurement bandwidth .187
10.6.3 Receiver sensitivity .189
10.6.4 Measurement automation .190
10.6.5 Power measuring receiver.191
10.7 EUT.192
10.7.1 Battery operated EUTs .193

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ETR 273-1-1: February 1998
10.8 Frequency counter.194
10.9 Salty man/salty-lite and test fixtures.194
10.10 Site factors .195
10.11 Random uncertainty.195
10.12 Miscellaneous .195
10.12.1 Personnel.195
10.12.2 Procedures .196
10.12.3 Methods .196
10.12.4 Specifications.198
History .199

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ETR 273-1-1: February 1998
Foreword
This ETSI Technical Report (ETR) has been produced by the Electromagnetic compatibility and Radio
spectrum Matters (ERM) Technical Committee of the European Telecommunications Standards Institute
(ETSI).
ETRs are informative documents resulting from ETSI studies which are not appropriate for European
Telecommunication Standard (ETS) or Interim European Telecommunication Standard (I-ETS) status. An
ETR may be used to publish material which is either of an informative nature, relating to the use or the
application of ETSs or I-ETSs, or which is immature and not yet suitable for formal adoption as an ETS or
an I-ETS.
The present document is part 1 of a multi-part Technical Report (ETR) covering Electromagnetic
compatibility and Radio Spectrum Matters (ERM) Improvement of radiated methods of measurement
(using test sites) and evaluation of the corresponding measurement uncertainties, as identified below:
Part 1-1: "Uncertainties in the measurement of mobile radio equipment characteristics;
Sub-part 1: Introduction";
Part 1-2: "Uncertainties in the measurement of mobile radio equipment characteristics; Sub-part 2:
Examples and annexes";
Part 2: "Anechoic chamber";
Part 3: "Anechoic chamber with a ground plane";
Part 4: "Open area test site";
Part 5: "Striplines";
Part 6: "Test fixtures";
Part 7: "Artificial human beings".
Introduction
The current-day accuracy of radiated tests on radio equipment leaves something to be desired. It is
believed that currently some measurements can be subject to as much as –15 dB uncertainty. This means
that a manufacturer with an equipment which is marginal as far as, for example, spurious emission levels
are concerned, could possibly send a test item to a number of test houses in the certain knowledge that
one of them will pass it. As an illustration of the existing accuracy, a test house invited to participate in
Round Robin tests organized as part of this project, whilst declining the invitation to take part, volunteered
the information that they could measure within –10 dB and they had the results to prove it (i.e. they were
proud that they could achieve that accuracy).
NOTE:–10 dB means that for a transmitter with nominal 1 W carrier power level, a measured
level anywhere between 100 mW and 10 W could be achieved.
In some cases engineers claim uncertainties of lower magnitude i.e. 2 or 3 dB. An examination of the
breakdown of the information available showed that different take different components into account, i.e.
there was no standard list of which "what uncertainty components to include".

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ETR 273-1-1: February 1998
The attached documentation is the outcome of the project team's investigation into the uncertainties
involved in radiated measurements and the information provided is divided as follows:
1) sources of uncertainty are identified for all types of test facility commonly used for radiated tests
(i.e. anechoic chambers, anechoic chambers with ground planes, open area test sites, striplines as
well as devices used to assist testing, namely test fixtures and artificial human bodies such as salty
columns);
2) means of calculating/deriving the magnitudes of the uncertainties for individual facilities;
3) verification procedures for all test facilities (at the 1,5m test height);
4) revised radiated test methods.
It is true that, historically, a lot of radiated tests have been carried out using the so-called direct field
method which is a one pass test and relies entirely on the calculation of the theoretical path loss between
EUT and antenna (performed using actual separation distance, frequency, etc.). This is a notoriously
inaccurate method and takes no account of reflections, mutual coupling, ambient signals, etc.
All the test methods presented in this ETR are so-called substitution measurements which are two stage
tests which replace/compare the unknown EUT with a known antenna. Since most communications devices
tend to be omni-directional in the azimuth plane, the known antenna is usually a dipole. It is assumed, and
indeed is a largely correct assumption, that whatever interfering objects, signals, etc., affect a dipole
similarly affect the test device. In this way, a large number of systematic measurement uncertainties have
no net effect on a test since any offset is present in both the test and substitution stages.

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ETR 273-1-1: February 1998
1 Scope
This ETSI Technical Report (ETR) gives the general background to the subject of measurement uncertainty
and proposes extensions and improvements relevant to radiated measurements. It also details the
methods of radiated measurements (test methods for mobile radio equipment parameters and verification
procedures for test sites) and provides the methods of evaluating the associated measurement
uncertainties.
This ETR provides a method to be applied to all the applicable standards and ETRs, and supports
ETR 027 [10].
2 References
Within this ETR, the following references apply:
[1] ANSI C63.5 (1988): "Electromagnetic Compatibility - Radiated Emission
Measurements in Electromagnetic Interference (EMI) Control - Calibration of
Antennas".
[2] "Antenna engineering handbook", R. C. Johnson, H. Jasik.
[3] "Antennas", John D. Kraus, Second edition, McGraw Hill.
[4] "Antennas and radio wave propagation", R. E. Collin, McGraw Hill.
[5] "Antenna theory", C. Balanis, J. E. Wiley 1982.
[6] CCITT Recommendation O.41: "Psophometer for use on telephone-type
circuits".
[7] CCITT Recommendation O.153: "Basic parameters for the measurement of
error performance at bit rates below the primary rate".
[8] "Control of errors on Open Area Test Sites", A. A. Smith Jnr. EMC technology
October 1982 page 50-58.
[9] EN 55020: "Electromagnetic immunity of broadcast receivers and associated
equipment".
[10] ETR 027 (1991): "Radio Equipment and Systems (RES); Methods of
measurement for private mobile radio equipment".
[11] ETR 028 - Edition 2 (1994): "Radio Equipment and Systems (RES);
Uncertainties in the measurement of mobile radio equipment characteristics".
[12] ETR 273-1-2 (1998): "Electromagnetic compatibility and Radio spectrum Matters
(ERM); Improvement of radiated methods of measurement (using test sites) and
evaluation of the corresponding measurement uncertainties; Part 1: Uncertainties
in the measurement of mobile radio equipment characteritics; Sub-part 2:
Examples and annexes".
[13] ETR 273-5 (1998): "Electromagnetic compatibility and Radio spectrum Matters
(ERM); Improvement of radiated methods of measurement (using test sites) and
evaluation of the corresponding measurement uncertainties; Part 5: Striplines".
[14] "Guide to the Expression of Uncertainty in Measurement", International
Organization for Standardization, Geneva, Switzerland, 1995.
[15] IEC 60050-161 (1990): "International Electrotechnical Vocabulary. Chapter 161:
Electromagnetic compatibility".

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ETR 273-1-1: February 1998
[16] The new IEEE standard dictionary of electrical and electronic terms, Fifth
edition, IEEE Piscataway, NJ USA 1993.
[17] Recommendation INC-1 (1980).
[18] "Wave transmission", F. R. Conner, Arnold 1978.
3 Definitions, symbols and abbreviations
3.1 Definitions
For the purposes of this ETR, the following definitions apply:
Audio Frequency (AF) load: Normally a resistor of sufficient power rating to accept the maximum audio
output power from the EUT. The value of the resistor is normally that stated by the manufacturer and is
normally the impedance of the audio transducer at 1 000 Hz.
NOTE 1: In some cases it may be necessary to place an isolating transformer between the
output terminals of the receiver under test and the load.
A-M1: A test modulation consisting of a 1 000 Hz tone at a level which produces a deviation of 12 % of the
channel separation.
A-M2: A test modulation consisting of a 1 250 Hz tone at a level which produces a deviation of 12 % of the
channel separation.
A-M3: A test modulation consisting of a 400 Hz tone at a level which produces a deviation of 12 % of the
channel separation. This signal is used as an unwanted signal for analogue and digital measurements.
AF termination: Any connection other than the audio frequency load which may be required for the
purpose of testing the receiver. (i.e. in a case where it is required that the bit stream be measured, the
connection may be made, via a suitable interface, to the discriminator of the receiver under test).
NOTE 2: The termination device is normally agreed between the manufacturer and the testing
authority and details included in the test report. If special equipment is required then it
is normally provided by the manufacturer.
antenna: That part of a transmitting or receiving system that is designed to radiate or to receive
electromagnetic waves.
antenna factor: Quantity relating the strength of the field in which the antenna is immersed to the output
voltage across the load connected to the antenna. When properly applied to the meter reading of the
measuring instrument, yields the electric field strength in V/m or the magnetic field strength in A/m.
antenna gain: The ratio of the maximum radiation intensity from an (assumed lossless) antenna to the
radiation intensity that would be obtained if the same power were radiated isotropically by a similarly
lossless antenna.
bit error ratio: The ratio of the number of bits in error to the total number of bits.
combining network: A multipole network allowing the addition of two or more test signals produced by
different sources for connection to a receiver input.
NOTE 3: Sources of test signals are normally connected in such a way that the impedance
presented to the receiver is 50 W. The combining networks are designed so that effects
of any intermodulation products and noise produced in the signal generators are
negligible.
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ETR 273-1-1: February 1998
correction factor: The numerical factor by which the uncorrected result of a measurement is multiplied to
compensate for an assumed systematic error.
confidence level: The probability of the accumulated error of a measurement being within the stated
range of uncertainty of measurement.
directivity: The ratio of the maximum radiation intensity in a given direction from the antenna to the
radiation intensity averaged over all directions (i.e. directivity = antenna gain + losses).
DM-0: A test modulation consisting of a signal representing an infinite series of "0" bits.
DM-1: A test modulation consisting of a signal representing an infinite series of "1" bits.
DM-2: A test modulation consisting of a signal representing a pseudorandom bit sequence of at least
511 bits in accordance with CCITT Recommendation O.153 [7].
D-M3: A test signal agreed between the testing authority and the manufacturer in the cases where it is not
possible to measure a bit stream or if selective messages are used and are generated or decoded within
an equipment.
NOTE 4: The agreed test signal may be formatted and may contain error detection and
correction. Details of the test signal are be supplied in the test report.
duplex filter: A device fitted internally or externally to a transmitter/receiver combination to allow
simultaneous transmission and reception with a single antenna connection.
error of measurement (absolute): The result of a measurement minus the true value of the measurand.
error (relative): The ratio of an error to the true value.
estimated standard deviation: From a sample of n results of a measurement the estimated standard
deviation is given by the formula:
n
(x-x)
i
∑
i
=1
s=
n-1
th
x being the i result of measurement (i = 1,2,3, .,n) and x the arithmetic mean of the n results
i
considered.
A practical form of this formula is:
X
Y-
n
s=
n-1
Where X is the sum of the measured values and Y is the sum of the squares of the measured values.
extreme test conditions: Conditions defined in terms of temperature and supply voltage. Tests are
normally made with the extremes of temperature and voltage applied simultaneously. The upper and lower
temperature limits are specified in the relevant testing standard. The test report states the actual
temperatures measured.
error (of a measuring instrument): The indication of a measuring instrument minus the (conventional)
true value.
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ETR 273-1-1: February 1998
free field: A field (wave or potential) which has a constant ratio between the electric and magnetic field
intensities.
free Space: A region free of obstructions and characterized by the constitutive parameters of a vacuum.
impedance: A measure of the complex resistive and reactive attributes of a component in an alternating
current circuit.
impedance (wave): The complex factor relating the transverse component of the electric field to the
transverse component of the magnetic field at every point in any specified plane, for a given mode.
influence quantity: A quantity which is not the subject of the measurement but which influences the value
of the quantity to be measured or the indications of the measuring instrument.
intermittent operation: Operation where manufacturer states the maximum time that the equipment is
intended to transmit and the necessary standby period before repeating a transmit period.
isotropic radiator: A hypothetical, lossless antenna having equal radiation intensity in all directions.
limited Frequency Range: The limited frequency range is a specified smaller frequency range within the
full frequency range over which the measurement is made.
NOTE 5: The details of the calculation of the limited frequency range are normally given in the
relevant testing standard.
maximum permissible frequency deviation: The maximum value of frequency deviation stated for the
relevant channel separation in the relevant testing standard.
measuring system: A complete set of measuring instruments and other equipment assembled to carry
out a specified measurement task.
measurement repeatability: The closeness of the agreement between the results of successive
measurements of the same measurand carried out subject to all the following conditions:
- the same method of measurement;
- the same observer;
- the same measuring instrument;
- the same location;
- the same conditions of use;
- repetition over a short period of time.
measurement reproducibility: The closeness of agreement between the results of measurements of the
same measurand, where the individual measurements are carried out changing conditions such as:
- method of measurement;
- observer;
- measuring instrument;
- location;
- conditions of use;
- time.
measurand: A quantity subjected to measurement.
noise gradient of EUT: A function characterizing the relationship between the RF input signal level and the
performance of the EUT, e.g., the SINAD of the AF output signal.
nominal frequency: One of the channel frequencies on which the equipment is designed to operate.

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ETR 273-1-1: February 1998
nominal mains voltage: The declared voltage or any of the declared voltages for which the equipment
was designed.
normal test conditions: The conditions defined in terms of temperature, humidity and supply voltage
stated in the relevant testing standard.
normal deviation: The frequency deviation for analogue signals which is equal to 12 % of the channel
separation.
psophometric weighting network: As described in CCITT Recommendation O.41 [6].
polarization: For an electromagnetic wave, the figure traced as a function of time by the extremity of the
electric vector at a fixed point in space.
quantity (measurable): An attribute of a phenomenon or a body which may be distinguished qualitatively
and determined quantitatively.
rated audio output power: The maximum audio output power under normal test conditions, and at
standard test modulations, as declared by the manufacturer.
rated radio frequency output power: The maximum carrier power under normal test conditions, as
declared by the manufacturer.
shielded enclosure: A structure that protects its interior from the effects of an exterior electric or
magnetic field, or conversely, protects the surrounding environment from the effect of an interior electric or
magnetic field.
SINAD sensitivity: The minimum standard modulated carrier-signal input required to produce a specified
SINAD ratio at the receiver output.
stochastic (random) variable: A variable whose value is not exactly known, but is characterized by a
distribution or probability function, or a mean value and a standard deviation (e.g. a measurand and the
related measurement uncertainty).
test load: The test load is a 50 W substantially non-reactive, non-radiating power attenuator which is
capable of safely dissipating the power from the transmitter.
test modulation: The test modulating signal is a baseband signal which modulates a carrier and is
dependent upon the type of EUT and also the measurement to be performed.
trigger device: A circuit or mechanism to trigger the oscilloscope timebase at the required instant. It may
control the transmit function or inversely receive an appropriate command from the transmitter.
uncertainty (random): A component of the uncertainty of measurement which, in the course
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