BS EN 54-24:2008 pdf free download – Fire detection and fire alarm systems一 Part 24: Components of voice alarm systems一Loudspeakers.
5 Tests
5.1 General
5.1.1 Atmospheric conditions for tests
Unless otherwise stated in a test procedure, the testing shall be carried out after the test specimen has been allowed to stabilize in the standard atmospheric conditions for testing described in EN 60068-1, as follows:
temperature: 15°C to 35 °C;
— relative humidity: 25 % to 75 %;
air pressure: 86 kPa to 106 kPa.
The temperature and humidity shall be substantially constant for each test where these standard atmospheric
conditions are applied.
5.1.2 Operating conditions for tests
Unless otherwise stated in a test procedure the test specimen shall be:
a) set at its highest power setting;
b) preconditioned in accordance with Annex A;
c) mounted in the acoustical environment as described in Annex A and as specified by the manufacturer (see 4.5.2 j)).
If different settings, except power settings, are available on the loudspeaker, such as tone control or adjustable parts (excluding external mounting bracket), the manufacturer shall specify the configuration(s) to be tested.
5.1.3 Mounting arrangements
For environmental conditioning tests, unless otherwise specified, the specimen shall be mounted by its normal means of attachment in accordance with the manufacturer’s instructions. If these instructions describe more than one method of mounting then the method considered to be most unfavourable shall be chosen for each test.
NOTE For some loudspeakers, due to their size, it might not be practical to conduct all of the environmental tests. In such cases, testing may be carried out on a smaller representative specimen, where this is deemed to produce a valid result for a given test.
5.1.4 Tolerances
The tolerances for the environmental test parameters shall be as given in the basic reference standards for the test (e.g. the relevant part of EN 60068).
If a specific tolerance or deviation limit is not specified in a requirement or test procedure, then a deviation limit of ± 5 % shall be applied.
5.1.5 Frequency response measurement and sensitivity calculation
5.1.5.1 Measuring arrangement
Measurements shall be made in accordance with Annex A.
5.1.6 Frequency response measurement and sensitivity calculation for loudspeakers requiring dedicated system equalization
5.1.6.1 General
This test method shall be used for loudspeakers which have been designed to operate with an associated active equalization network.
NOTE Testing of active equalizers is not covered by this European Standard.
5.1.6.2 Measuring arrangement
Measurements shall be made in accordance with Annex A.
An active equalizer inserted between the clipping network and the power amplifier shall be used in the measurements.
5.1.6.3 Basic measurements
Basic measurements shall be performed as described in 5.1.5.2.
5.1.7 Provision for tests
The following shall be provided for testing compliance with this European Standard:
a) seven specimens of type A or nine specimens of type B loudspeaker with any mounting, accessories etc.; b) the data required in 4.5.2.
The specimens submitted shall be representative of the manufacturer’s normal production with regard to their construction and settings.