BS 5944-6:1992

Committees responsible
National foreword
Introduction
Method
1 Scope
2 Normative references
3 Definitions
4 Measurement uncertainty
5 Test environment
6 Instrumentation
7 Installation conditions
8 Operating conditions
9 Location and number of sound measurement points
10 Test procedure
11 Calculation of surface sound pressure levels and
     sound power levels
12 Information to be recorded
13 Test report
14 Identification statement
Annexes
A Errors and classes of measurement
B Bibliography
Tables
1 Standard deviation of sound power level
     determinations
2 Allowable variations of mean indicated values of
     controlled parameters
3 Coordinates of microphone locations shown in figure
     1
A.1 Permissible systematic errors of measuring
     instruments as determined during calibration
Figures
1 Microphone array on rectangular parallelepiped
     measuring surface

Describes procedures for the determination of the sound power levels of a hydraulic fluid power pump, under controlled conditions of operation and installation, suitable for giving a basis for comparing the noise levels of pumps in terms of one-third octave band power level a-weighted sound power level. Applies to all types of hydraulic fluid power pumps operating under steady-state conditions, except for any limitations imposed by the test environment size. Coverage includes: definitions, measurement uncertainty, instrumentation, installation conditions, and operating conditions. Includes annexes and tables.

This part of ISO 4412 describes procedures for the determination of the sound power levels of a hydraulic fluid power pump, under controlled conditions of installation and operation, suitable for providing a basis for comparing the noise levels of pumps in terms of

• A-weighted sound power level;
• one-third octave band power level.

From these sound power levels, if required, reference sound pressure levels may be calculated for reporting purposes (see clause 11).

For general purposes, the frequency range of interest includes the one-third octave bands with centre frequencies between 100 Hz and 10 000 Hz¹⁾.

This part of ISO 4412 is applicable to all types of hydraulic fluid power pumps operating under steady-state conditions, irrespective of size, except for any limitations imposed by the size of the test environment (see clause 3).