Verification and testing of approved devices
8.—(1) The sensitivity of a device approved under regulation 4 or 5 must be verified before and after its use, using a sound calibrator.
(2) Where–
(a)the sensitivity of the device has been verified after the measurement of noise in accordance with paragraph (1); and
(b)the sensitivity level of the device has changed by 0.5 decibels or more from the level indicated when the sensitivity of the device was verified before the measurement of noise,
that measurement may not be used for any of the purposes set out in these Regulations.
(3) A device approved under regulation 4 or 5 and the sound calibrator used in relation to it, must be tested in accordance with the requirements of BS 7580–
(a)no more than 2 years before it is used for any of the purposes set out in these Regulations; and
(b)at least once every 2 years following that test.