What is ISO 7779-Measurement of airborne noise about?
ISO 7779 is an international standard that discusses acoustics. ISO 7779 specifies procedures for measuring and reporting the noise emission of information technology and telecommunications (ITT) equipment. The basic emission quantity is the A-weighted sound power level, which can be used for comparing equipment of the same type but from different manufacturers, or for comparing different equipment.
Three basic noise emission standards for the determination of the sound power levels are specified in ISO 7779 in order to avoid undue restrictions on existing facilities and experience. ISO 3741 specifies comparison measurements in a reverberation test room; ISO 3744 and ISO 3745 specify measurements in an essentially free field over a reflecting plane. Any of these three basic noise emission standards can be selected and used exclusively in accordance with ISO 7779 when determining the sound power levels of a machine.
Who is ISO 7779-Measurement of airborne noise for?
ISO 7779 the measurement of airborne noise emitted by information technology and telecommunications equipment is relevant to:
- Manufacturers of telecommunications equipment
- Several types of manufacturers
- Testing laboratories
- Acousticians
Why should you use ISO 7779-Measurement of airborne noise?
A wide variety of methods have been applied by individual manufacturers and users to satisfy equipment or application needs. These diverse practices have, in many cases, made a comparison of noise emission difficult. ISO 7779 simplifies such comparisons and is the basis for the declaration of the noise emission levels of ITT equipment. To ensure accuracy, validity, and acceptability. ISO 7779 specifies methods for the measurement of airborne noise emitted by ITT equipment.
ISO 7779 is based on the basic International Standards for determination of the sound power level and for determination of the emission sound pressure level at the operator position and bystander positions. ISO 7779 is suitable for type tests and provides methods for manufacturers and testing laboratories to obtain comparable results. The methods specified in ISO 7779 allow the determination of noise emission levels for a functional unit tested individually. The procedures apply to equipment that emits broad-band noise, narrow-band noise, and noise that contains discrete-frequency components, or impulsive noise. In conclusion, the guidance of ISO 7779 enables you to determine the sound power levels of ITT equipment.
What’s changed since the last update?
BS EN ISO 7779:2018 replaces ISO 7779:2010, which has been technically revised. The main changes compared to the previous edition are as follows:
- Addition of new 3.3 corresponding to new Clause 9
- In 6.4.6, the microphone calibration procedures were amended to be consistent with those of industrial counterpart, ECMA-74
- In 7.3 (7.3.1), the procedure for test environment qualification was amended to clarify that any frequency bands, typically low in frequency, not significantly affecting A-weighted sound power level need not meet the Hemi-anechoic room qualification criteria for the purposes of determining A-weighted sound power level
- In 7.4.6, the microphone calibration procedures were amended to be consistent with those of industrial counterpart, ECMA-74
- In 8.6, new 8.6.1 was inserted to clarify the method of defining operator position and bystander positions