4.DURABILITY TEST
4.1.The audible warning device must be supplied with the nominal voltage at the conductor resistance specified in sections 3.3 to 3.5 and be operated:
10 000 times in the case of warning devices intended mainly for mopeds, motorcycles and tricycles developing a power not exceeding 7 kW,
50 000 times in the case of warning devices intended mainly for motorcycles and tricycles developing a power of more than 7 kW respectively,
at a rate of one second on followed by four seconds off. During the test the audible warning device must be exposed to a forced draught having a speed of rougly 10 m/sec.
4.2.If a test is conducted within an insulated chamber that chamber must be of sufficient volume to ensure normal dissipation of the heat given off by the warning device during the durability test.
4.3.The ambient temperature within the test chamber must lie between + 15 and + 30 oC.
4.4.If, after half the required number of operations, the characteristics of the sound level have altered as compared with before the test the audible warning device may be reset. When the total number of operations required have been completed the audible warning device must successfully complete the test described in section 3, where necessary after being further reset.
4.5.Electro-pneumatic audible warning devices may be lubricated with the oil recommended by their manufacturer every 10 000 operations.
