Customer Support: 131 242

  • There are no items in your cart
We noticed you’re not on the correct regional site. Switch to our AMERICAS site for the best experience.
Dismiss alert

BS 7135-1:1989

Superseded
Superseded

A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.

View Superseded by
superseded

A superseded Standard is one, which is fully replaced by another Standard, which is a new edition of the same Standard.

Noise emitted by computer and business equipment Method of measurement of airborne noise
Available format(s)

Hardcopy , PDF

Superseded date

25-10-2001

Language(s)

English

Published date

31-08-1989

National foreword
Committees responsible
Method
0 Introduction
1 Scope and field of application
2 Conformance
3 References
4 Definitions
5 Method for determining sound power levels of
    equipment in reverberation rooms
6 Method for determining sound power levels of
    equipment over a reflecting plane
7 Method for measuring sound pressure levels at the
    operator and bystander positions
Annexes
A Standard test table
B Alternative measurement surfaces for sound power
    measurements in accordance with clause 6
C Installation and operating conditions for specific
    equipment categories
D Measurement of impulsive sound pressure levels and
    discrete tones at the operator position
Tables
1 Uncertainty in determining sound power levels in a
    reverberation room
2 Minimum room volume as a function of the lowest
    frequency band of interest
3 Procedures to be followed for measuring discrete-
    frequency components or narrow bands of noise
4 Number of microphone positions required and
    constant k for determining the number of equipment
    locations
5 Values of the A-weighting Aj, for j = 1 to jmax = 7
6 Values of the A-weighting Aj, for j = 1 to jmax = 21
7 Uncertainty in determining sound power levels in a
    free field over a reflecting plane
8 Coordinates of key microphone positions for
    arrangement 1
9 Coordinates of key microphone positions for
    arrangement 2
10 Uncertainty in determining time-average sound
    pressure level at the operator position over a
    reflecting plane
11 Hemispherical measurement surface - 10 measurement
    positions
12 Hemispherical measurement surface - 10 measurement
    positions
13 Number of characters to be used
Figures
1 Measurement surface with 9 microphone positions
2 Measurement surface for floor-standing equipment in
    front of a wall
3 Examples of microphone positions for standing and
    seated operators
4 Example of a standard test table
5 Hemispherical surface - 10 measurement positions
6 Hemispherical measurement surface - Circular paths
    for microphone traverse
7 Insertion of a single sheet of paper
8 Example of full print page: line length of 60 to 110
    characters
9 Example of full print page: line length of more than
    110 characters

Methods for determining the A-weighted sound power levels based on measurements in reverberant rooms or in free-field conditions over a reflecting plane, and A-weighted sound pressure levels at the operator or bystander positions.

Committee
EH/1
DocumentType
Standard
Pages
46
PublisherName
British Standards Institution
Status
Superseded
SupersededBy

Standards Relationship
ISO 7779:2010 Identical

BS 7135-3:1989 Noise emitted by computer and business equipment Method for determining and verifying declared noise emission values
BS 7135-2:1989 Noise emitted by computer and business equipment Method of measurement of high-frequency noise

BS 4196-4:1981 Sound power levels of noise sources Engineering methods for determination of sound power levels for sources in free-field conditions over a reflecting plane
BS 4196-0:1981 Sound power levels of noise sources Guide for the use of basic standards and for the preparation of noise test codes
BS 4196-2:1981 Sound power levels of noise sources Precision methods for determination of sound power levels for discrete-frequency and narrow-band sources in reverberation rooms
BS 7135-2:1989 Noise emitted by computer and business equipment Method of measurement of high-frequency noise
BS 7135-3:1989 Noise emitted by computer and business equipment Method for determining and verifying declared noise emission values
BS 4196-5:1981 Sound power levels of noise sources Precision methods for determination of sound power levels for sources in anechoic and semi-anechoic rooms
ISO 6926:2016 Acoustics Requirements for the performance and calibration of reference sound sources used for the determination of sound power levels
BS 4196-1:1981 Sound power levels of noise sources Precision methods for determination of sound power levels for broad-band sources in reverberation rooms
BS 4196-3:1981 Sound power levels of noise sources Engineering methods for determination of sound power levels for sources in special reverberation test rooms

View more information
$541.18
Including GST where applicable

Access your standards online with a subscription

Features

  • Simple online access to standards, technical information and regulations.

  • Critical updates of standards and customisable alerts and notifications.

  • Multi-user online standards collection: secure, flexible and cost effective.

Need help?
Call us on 131 242, then click here to start a Screen Sharing session
so we can help right away! Learn more