EN 61237-2:1995
(Main)Broadcast video tape recorders - Methods of measurement - Part 2: Electrical measurements of analogue composite video signals
Broadcast video tape recorders - Methods of measurement - Part 2: Electrical measurements of analogue composite video signals
Describes the methods of measurement, test signals and procedures which may apply to characteristics of video recording/playback machines mainly intended for professional use.
Meßverfahren für Videobandgeräte für den Rundfunk - Teil 2: Elektrische Messungen für analoge Composite-Videosignale
Magnétoscopes de radiodiffusion - Méthodes de mesure - Partie 2: Mesures électriques pour les signaux vidéo analogiques composites
Décrit les méthodes de mesure, les signaux et les procédures d'essai qui peuvent s'appliquer aux caractéristiques des appareils d'enregistrement/de lecture vidéo, ces appareils étant principalement destinés à une utilisation professionnelle.
Broadcast video tape recorders - Methods of measurement -- Part 2: Electrical measurements of analogue composite video signals (IEC 61237-2:1995)
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
01-april-1999
Broadcast video tape recorders - Methods of measurement -- Part 2: Electrical
measurements of analogue composite video signals (IEC 61237-2:1995)
Broadcast video tape recorders - Methods of measurement -- Part 2: Electrical
measurements of analogue composite video signals
Meßverfahren für Videobandgeräte für den Rundfunk -- Teil 2: Elektrische Messungen
für analoge Composite-Videosignale
Magnétoscopes de radiodiffusion - Méthodes de mesure -- Partie 2: Mesures électriques
pour les signaux vidéo analogiques composites
Ta slovenski standard je istoveten z: EN 61237-2:1995
ICS:
33.160.40 Video sistemi Video systems
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
CEI
NORME
IEC
INTERNATIONALE
1237-2
INTERNATIONAL
Première édition
STANDARD
First edition
1995-05
Magnétoscopes de radiodiffusion —
Méthodes de mesure —
Partie 2:
Mesures électriques pour les signaux vidéo
analogiques composites
Broadcast video tape recorders —
Methods of measurement —
Part 2:
Electrical measurements of analogue
composite video signals
Copyright — all rights reserved
© CEI 1995 Droits de reproduction réservés —
No part of this publication may be reproduced or utilized in
Aucune partie de cette publication ne peut étre reproduite ni
any form or by any means, electronic or mechanical,
utilisée sous quelque forme que ce soit et par aucun pro-
including photocopying and microfilm, without permission
cédé, électronique ou mécanique, y compris la photocopie et
les microfilms, sans l'accord écrit de l'éditeur. in writing from the publisher.
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- 3 -
1237-2 ©IEC:1995
CONTENTS
Page
FOREWORD 7
Clause
1 Scope and object
2 Normative references
13 3 General
4 Test conditions
5 Measuring methods and test signals
15 5.1 Manual and automatic measurements
5.2 Measurement of differences between adjacent tracks (fields/segments)
15 5.3 Procedure of measurement
5.4 Test signals
5.4.1 Introduction
5.4.2 Amplitudes and characteristics of test signals
5.4.3 Test signal arrangement
Measurements of characteristics 6
6.1 Amplitude of output signals in E-E mode and playback
6.1.1 Luminance bar amplitude error
19 6.1.2 Synchronizing pulse amplitude error
6.1.3 Burst amplitude error 21
6.2 Short and line time distortions 21
6.2.1 K2T factor 21
6.2.2 2T/bar ratio 23
6.2.3 Bar tilt
6.2.4 Base-line distortion 25
Chrominance-luminance gain inequality 27
6.3
delay inequality 29
Chrominance-luminance
6.4
6.5 Amplitude/frequency characteristics
6.5.1 Luminance
6.5.2 Chrominance
6.6 Non-linear distortions
6.6.1 Differential gain
6.6.2 Differential gain versus frequency
6.6.3 Differential phase
6.6.4 Group delay
cross-talk/intermodulation Chrominance-luminance
6.7
6.8 Luminance signal-to-noise ratio 39
signal-to-noise ratio 6.9 Chrominance
41 6.9.1 Measurement of PAL/NTSC colour video signals
SECAM colour video signals
6.9.2 Measurement of
- 5 -
1237-2 ©IEC:1995
Page
Clause
6.10 Field time distortions
6.10.1 Vertical tilt
6.11 Long time distortion 49
6.11.1 Signal bounce 49
6.11.2 Power supply interference
7 Special measurements
51 7.1 FM characteristic frequencies
7.2 Non-linear preemphasis
55 7.3 Noise coring
7.4 Moiré
7.5 Time base errors (measurements before time base error corrector)
7.5.1 Velocity errors
7.5.2 Phase step 59
7.5.3 Jitter 59
7.5.4 Time base errors after correction
7.6 Sc/H phase
Annexes
A - Test signals elements 69
B - 625-line systems
C - 525-line systems
D - Bibliography
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1237-2 © I EC:1995
INTERNATIONAL ELECTROTECHNICAL COMMISSION
BROADCAST VIDEO TAPE RECORDERS —
METHODS OF MEASUREMENT —
Part 2: Electrical measurements of analogue
composite video signals
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.
The formal decisions or agreements of the IEC on technical matters, prepared by technical committees on
2)
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 1237-2 has been prepared by sub-committee 60B: Video
recording, of IEC technical committee 60: Recording.
IEC 698: Measuring methods for television tape machine, has been withdrawn from the
catalogue. However, this publication still applies, on the one hand, to materials specified
in IEC 347: Transverse track video recorders (second edition) which are not included in
the new draft and, on the other hand, to mechanical measurements on transverse track
video recorders (only).
The text of this standard is based on the following documents:
DIS Reports on voting
608(CO)159
60B(CO)171
60B(CO)159A
rt
Full information on the voting for the approval of this standard can be found in the repo
on voting indicated in the above table.
1237-2 © IEC:1995 - 9 -
IEC 1237 consists of the following parts, under the general title - Methods of measure-
ment for broadcast video tape recorders:
Part 1: Mechanical measurements
Part 2: Electrical measurements of analogue composite video signals
Part 3: Electrical measurements of analogue component video signals
Part 4: Measurement of audio performance - analogue
Part 5: Electrical measurements of digital composite video signals and digital audio
signals
Part 6: Electrical measurements of digital component video signals and digital. audio
signals
only.
Annexes A, B, C and D are for information
1237-2 ©IEC:1995 - 11 -
BROADCAST VIDEO TAPE RECORDERS —
METHODS OF MEASUREMENT —
Part 2: Electrical measurements of analogue
composite video signals
1 Scope and object
This part of IEC 1237 describes the test signals and measuring methods for equipments
mainly dedicated to record/playback analogue composite TV-signals on magnetic tape on
reels or in cassettes.
The allowable tolerances for the rated values for acceptable performance are not given
in this standard, but may be derived from the specifications for the related system, i.e.
appropriate publications, manufacturers' specifications, etc.
The necessary reference and calibration tapes are either mentioned in the specific
IEC publication of equipment under test or included in IEC 1105 (reference tapes) and
IEC 1295 (calibration tapes).
The principal object of this standard is to describe the methods of measurement, test
signals and procedures which may apply to characteristics of video recording/playback
machines mainly intended for professional use. The measuring methods described here-
after do not directly concern home equipment and it would appear that some will be
difficult to apply to them.
2 Normative references
The following normative documents contain provisions which, through reference in this
text, constitute provisions of this part of IEC 1237. At the time of publication, the editions
rties to agree-
indicated were valid. All normative documents are subject to revision, and pa
ments based on this pa rt of IEC 1237 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 244-10: 1986, Methods of measurement for radio transmitters - Part 10: Methods of
rtion test signals
measurements for television transmitters and transposers employing inse
IEC 756: 1991, Non-broadcast video tape recorders - Time base stability
IEC 883: 1987, Measuring method for chrominance signal-to-random noise ratio for video
tape recorders
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1237-2 © I EC :1995
Non-broadcast video tape recorders - Methods of measurement -
IEC 1041-1: 1990,
Part 1: General video (NTSC/PAL) and audio (longitudinal) characteristics
Non-broadcast video tape recorders - Methods of measurements -
IEC 1041-2: 1994,
Part 2: Video characteristics chrominance
Nomenclature and description of colour bar signals
CCIR Recommendation 471-1: 1990,
(Vol. XI-1)
Transmission performance of television circuits
CCIR Recommendation 567-3: 1990,
XII)
designed for use in international connections (Vol.
3 General
This standard deals with the application of measuring methods designed for general use
television production and transmission as well as special measurement techniques for
television tape machines.
The methods are applicable to acceptance tests, performance comparisons and, as far as
possible, to routine checks. To insure that the results obtained at a specific time at a
specific place are comparable to other measurements it is advisable to specify the test
signals, measuring devices and types of tapes used together with the results obtained.
Since measurements of television tape machines on the basis of a single test-line per field
may not be fully representative of the full-field performance (see 5.2 and 5.3), they may
give results which differ from those obtained or calculated with full-field test signals. There-
fore it is necessary to additionally specify the measuring method i.e.
- single line measurement (line number);
block measurement (start-line, step-by-step line(s), number of steps);
-
- full-field measurement.
Additionally it should be stated if the selection of lines coincides with a single
record/playback head only.
4 Test conditions
If not otherwise stated all measurements shall be carried out at the following atmospheric
conditions.
(20 ± 1) °C
Temperature
(50 ± 2) %
Relative humidity
86 kPa to 106 kPa
Air pressure
24 h
Conditioning before testing
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1237-2 © IEC:1995
methods and test signals
5 Measuring
5.1 Manual and automatic measurements
If an automatic measuring device is designed to give reliable results under the special
conditions of television tape recording/playback as e.g. drop-out, jitter, time-base errors,
head switching or partly insufficient head-to-tape contact, a significant improvement in
measuring speed, accuracy and comparability of results can be achieved.
Therefore preference was given to measuring methods which can be carried out by auto-
matic measuring equipment or which are suitable for automatic measuring techniques.
Except where a distinction is made in particular clauses between manual and automatic
methods of measurement, the measurement procedures given in this standard are valid
for both methods. However, although in the case of automatic measurements the
procedure is carried out automatically by the test signal analyzer, the various steps are
described as if they were performed manually.
Measurement of differences between adjacent tracks (fields/segments)
5.2
All currently standardized recording formats make use of segmented recording techniques.
The length of the segments (tracks) varies between approximately 16 lines and one field
where the latter is often termed "non segmented recording" which only indicates that there
is no cut within the field.
two or more heads are used for record and playback of the video information to and
Since
from the tracks it is desirable to restrict the measurement to segments related to a specific
head. This requires a special signal arrangement which provides identical information to
the heads or segments in turn.
A suitable arrangement for most formats is to repeat a packet of up to 16 different signals
of a duration of one line within a field and to make the signals identical in both fields.
5.3 Procedure of measurement
The measurements shall be carried out by measuring the playback signal after recording
on the same equipment (best-case configuration).
cases, if the multigeneration-performance of a video recording system
In ce rtain particular
by measuring the playback signal af-
is measured, the measurements shall be carried out
ter recording on a different machine (worst-case configuration).
If the television tape machine under test is equipped with external controls, e.g. tracking
control, gain control, etc. these controls shall be set to their preset or mid-position for all
measurements.
1237-2 ©IEC:1995 - 17 -
5.4 Test signals
5.4.1 introduction
A representative range of test signals is shown in annexes B and C (figures B.1 to B.6
and C.1 to C.7). For ease of reference they are indicated by roman numerals. The test
signals elements are defined in annex A.
The terms concerning the components and values of a composite colour video signal are
given after figure A.3.
5.4.2 Amplitudes and characteristics of test signals
The peak-to-peak amplitude of a monochrome composite video signal, e.g. from sync tip
to white level, shall be
Vp-p
1,0
The nominal value of the luminance component a
...
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