It shall be lawful for a person authorized under the provisions of section 287 or 288 to make an entry for the purpose of inspection, or of search, to open or cause to be opened a door, gate or other barrier —
(a) if he considers the opening thereof necessary for the purpose of such entry, inspection or search, and
(b) if the owner or occupier is absent, or being present, refuses to open such door, gate or barrier.