For the purposes of sections 80, 80A, 81, 83A(1), 84(7) and 84H(2)(a) of the Act, a mobile digital RSC is used in the prescribed manner if—
(a) the speed calculation unit is used in accordance with operating instructions approved by a testing officer; and
(b) the speed calculation unit has been tested in accordance with regulation 38 within 12 months before the occasion of its use; and
(c) the speed calculation unit has been sealed in accordance with regulation 39 at the time that it was last tested.