IEC 61988-2-5:2012

IEC 61988-2-5 ®
Edition 1.0 2012-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Plasma display panels –
Part 2-5: Measuring methods – Acoustic noise

Panneaux d'affichage à plasma –
Partie 2-5: Méthodes de mesure – Bruit acoustique

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IEC 61988-2-5 ®
Edition 1.0 2012-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Plasma display panels –
Part 2-5: Measuring methods – Acoustic noise

Panneaux d'affichage à plasma –

Partie 2-5: Méthodes de mesure – Bruit acoustique

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX L
ICS 31.260 ISBN 978-2-83220-089-6

– 2 – 61988-2-5 © IEC:2012
CONTENTS
FOREWORD . 3
1 Scope . 5
2 Normative references . 5
3 Terms and definitions . 5
4 Structure of measuring equipment . 6
5 Standard measuring conditions . 6
6 Measuring method . 6
6.1 Purpose . 6
6.2 Measuring equipment . 6
6.2.1 Equipment list . 6
6.2.2 Anechoic chamber . 6
6.2.3 Silent room . 6
6.2.4 Sound level meter. 7
6.3 Measuring conditions . 7
6.3.1 Layout . 7
6.3.2 Standard measuring distance . 7
6.3.3 Measuring point . 7
6.3.4 Input video signal . 7
6.3.5 Warm-up conditions . 7
6.3.6 Measuring frequency range . 8
6.3.7 Measuring bandwidth . 9
6.3.8 Weighting filter . 9
6.4 Calculation of overall acoustic noise level . 9
6.5 Measurement procedure . 9
6.6 Measurement report . 10
Bibliography . 11

Figure 1 – Setting of measuring equipment . 8
Figure 2 – Measuring point . 8

Table 1 – Example of acoustic noise measurement result . 10

61988-2-5 © IEC:2012 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
PLASMA DISPLAY PANELS –
Part 2-5: Measuring methods –
Acoustic noise
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC
Publication(s)”). 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-
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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 IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 61988-2-5 has been prepared by IEC technical committee 110:
Electronic display devices.
The text of this standard is based on the following documents:
FDIS Report on voting
110/355/FDIS 110/373/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
A list of all the parts in the IEC 61988 series, published under the general title Plasma display
panels, can be found on the IEC website.

– 4 – 61988-2-5 © IEC:2012
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
61988-2-5 © IEC:2012 – 5 –
PLASMA DISPLAY PANELS –
Part 2-5: Measuring methods –
Acoustic noise
1 Scope
This part of IEC 61988 determines the following measuring methods for characterizing the
performance of PDP modules (plasma display modules):
– Acoustic noise
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and
are indispensable for its application. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60050 (all parts), International Electrotechnical Vocabulary (available at
)
IEC 60068-1, Environmental testing – Part 1: General and guidance
IEC 61672-1, Electroacoustics – Sound level meters – Part 1: Specifications
IEC 61988-1, Plasma display panels – Part 1: Terminology and letter symbols
IEC 61988-2-1, Plasma display panels – Part 2-1: Measuring methods – Optical and
optoelectrical
IEC 61988-4, Plasma display panels – Part 4: Climatic and mechanical testing methods
ISO 7574-1, Acoustics – Statistical methods for determining and verifying stated noise
emission values of machinery and equipment – Part 1: General considerations and definitions
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-801:1994,
IEC 60068-1 and IEC 61988-1 and the following apply.
3.1
acoustic noise
audible noise generated by the driving of PDP module, and caused by the vibrations of panel,
electric components, wirings and circuits
Note 1 to entry: The noise depends on the image displayed, module (panel) temperature, environmental pressure
and surrounding mechanical (acoustic) conditions.
3.2
acoustic noise level
L
sum of acoustic noise levels that are measured at the individual octave band in the measuring
frequency range
– 6 – 61988-2-5 © IEC:2012
3.3
acoustic noise level at f Hz
L
f
noise amplitude that is measured at the centre frequency of individual 1/3 octave bands in the
centre frequency range of 250 Hz ~ 20 000 Hz
Note 1 to entry: The centre frequencies of the individual 1/3 octave bands are 250 Hz, 315 Hz, 400 Hz, 500 Hz, …
20 000 Hz.
4 Structure of measuring equipment
The system diagrams and/or driving conditions of the measuring equipment shall comply with
the structure specified in each item.
5 Standard measuring conditions
Measurements shall be carried out under the standard environmental conditions defined in
IEC 61988-2-1, i.e. at a temperature of 25 °C ± 3 °C, a relative humidity of 25 % to 85 %, and
a pressure of 98 kPa to 104 kPa, if not otherwise specified in the relevant specifications.
When different conditions are used, they shall be noted in the report.
The standard reference atmosphere defined in IEC 61988-4, i.e. 25 °C and 101,3 kPa, is
applied.
6 Measuring method
6.1 Purpose
The purpose of this method is to measure the acoustic noise of a PDP module.
6.2 Measuring equipment
6.2.1 Equipment list
The following equipment shall be used:
a) anechoic chamber or silent room;
b) sound level meter; and
c) pattern generator.
NOTE Microphone and FFT (Fast Fourier Transformation) analyser with control PC can be used when calibrated
against a calibrated sound level meter.
6.2.2 Anechoic chamber
An anechoic chamber with an enough size for the measurement should be used. The details
of the anechoic chamber shall be noted on the report. The conditions of the anechoic
chamber defined in ISO 7574-1 shall be applied, if not otherwise defined in this measurement
method. The background noise level of the anechoic chamber shall be measured and noted in
the report.
6.2.3 Silent room
When any proper anechoic chamber is not available, a silent room where the background
sound level is small enough for the measurement can be used. In the case of using a silent
room, the size of the room should be large enough and the sound reflection from the wall,
ceiling and floor shall not affect the measurement result. The background noise level of the
silent room shall be measured and noted in the report.

61988-2-5 © IEC:2012 – 7 –
6.2.4 Sound level meter
A well calibrated sound level meter shall be used. The details are defined in
IEC 61672-1.
NOTE Microphone and FFT analyser with control PC can be used when calibrated against a calibrated sound
level meter.
6.3 Measuring conditions
6.3.1 Layout
The PDP module shall be set in the anechoic chamber or the silent room as shown in Figure 1.
The driving power source, control PC and pattern generator should be set outside the room.
The power and signal lines shall be arranged in order to be free from any unwanted vibrations.
The microphone shall be aligned perpendicular to the screen centre. The details of the
measuring layout applied shall be noted in the report.
6.3.2 Standard measuring distance
The standard measuring distance is 1 m. When other measuring distance is applied, this shall
be noted on the report.
6.3.3 Measuring point
The measurement shall be carried out at the centre of the screen area as shown in Figure 2.
The acoustic noise levels of front and rear sides of PDP module shall be measured. When
different points are measured, this shall be noted in the report.
6.3.4 Input video signal
Full screen white at the level of 100 %, full screen black and other signals defined in the
relevant specification shall be applied. The applied signals shall be noted in the report.
6.3.5 Warm-up conditions
The PDP module shall be warmed up for 30 minutes or longer under the condition of full
screen white to stabilize the panel at around the highest operating temperature in the standard
environmental conditions. When another warm-up condition is applied, it shall be noted in the
report.
NOTE Gas pressure in a PDP panel becomes higher with the increase of panel temperature. The acoustic noise
of the panel usually changes with gas pressure.

– 8 – 61988-2-5 © IEC:2012
Anechoic chamber or silent room
PDP module
Driving
power
Microphone/sound
source
level meter

Pattern Control
generator PC
Measuring distance
IEC  905/12
Front and rear sides of PDP module are measured.
The microphone is aligned perpendicular to screen.
The power and signal lines are set free from any unexpected vibrations.
Figure 1 – Setting of measuring equipment

H/2
V/2
Measuring point
V
H
IEC  906/12
Figure 2 – Measuring point
6.3.6 Measuring frequency range
The standard measuring frequency range is 250 Hz ~ 20 000 Hz. When another measuring
frequency is applied, it shall be noted on the report.
NOTE The lowest bound of measuring frequency range depends on the cut-off frequency of anechoic chamber.
The cut-off frequency of anechoic chamber is defined as follows:
v
s
Cut-off frequency =
4
w
61988-2-5 © IEC:2012 – 9 –
where, v is the velocity of sound and  is the length of wedge foam (shape of sound absorber) in anechoic
s w
chamber. If  is 340 mm, the cut-off frequency is about 250 Hz and the results for frequencies less than 250 Hz
w
are meaningless.
6.3.7 Measuring bandwidth
The standard measuring bandwidth is 1/3 octave band.
6.3.8 Weighting filter
The acoustic weighting of FFT analyser should be A-weighted (dBA). A-weighting filter is used
to emphasize frequencies around 3 kHz ~ 6 kHz where the human ear is most sensitive, while
attenuating very high and very low frequencies to which the ear is insensitive.
NOTE The unit, A-weighted decibel, is abbreviated dBA or dB(A). The decibel (dB) can be used for convenience.
6.4 Calcula
...