BS EN ISO 7779:2018 pdf free

BS EN ISO 7779:2018 pdf free.Acoustics – Measurement of airborne noise emitted by information technology and telecommunications equipment
Annex C specifies such conditions for many categories of equipment and shall be followed. However, if the specified conditions are clearly contrary to the objective of providing uniform conditions closely corresponding to the intended use of the product, then an additional mode or modes closely related to the intended use shall be defined, tested and described in the test report. Any subsequent declaration shall either:
一declare both values, indicating that one is based on Annex C and that the other is declared by the manufacturer to be typical use for the intended application; or
一declare only the latter, indicating that it is not based on Annex C but is declared by the manufacturer to be typical use for the intended application.
When there are multiple operating modes specified in Annex C, at a minimum, the most typical operating mode shall be chosen for the measurement. This mode shall be clearly described in the test report.
The equipment shall be operated for a sufficient period of time before proceeding with the acoustical test to allow temperature and other pertinent conditions to stabilize.
The noise shall be measured with the equipment in both the idle and operating modes. If the equipment is designed to perform different functions, such as manual typing and automatic printing of stored information or for printing in different print qualities, unless otherwise specified in Annex C, the noise of each individual mode shall be determined and recorded. For equipment which, in normal functional operation, performs several operating modes, such as document insertion, reading, encoding, printing and document eject, and for which a typical operational cycle has not been defined in Annex C, such a typical cycle shall be defined for the measurements. This mode shall be clearly described in the test report.
For rack-mounted equipment in which the operation of several functional units is possible, the units intended to operate together shall do so during the test; all other units shall be in idle mode. In the absence of operational specifications provided by Annex C or by the manufacturer, an operating mode that represents the most typical usage shall be defined and tested. This mode shall be clearly described in the test report.BS EN ISO 7779 pdf download.