An authorised examiner must not, for these regulations—
(a) inspect or test a vehicle included in a class of vehicles that is not mentioned in his or her certificate of appointment; or
(b) inspect or test a vehicle other than at approved premises; or
(c) without reasonable excuse, refuse to inspect or test a vehicle included in a class of vehicles mentioned in his or her certificate of appointment; or
(d) knowing that a vehicle inspected or tested by the examiner, or any part or equipment of the vehicle, does not comply with the applicable vehicle standards, certify in a certificate issued under regulation 146 that it does comply.