The county superintendent shall observe the following limitations in purchasing or replacing capital outlay items:
(a) For the operation of a library and supplementary book service, the purchases of books and other instructional materials shall be limited to those books and materials adopted by the county board of education.
(b) For the operation of audio-visual services, the purchases of films and film strips shall be limited to films and film strips adopted by the county board of education.
(c) The purchase of projection equipment shall be limited to:
(1) Equipment for use of the staff of the county superintendent of
schools for authorized curricular and special services.
(2) Equipment for use of such staff in programs of orienting school districts to audio-visual services.
(3) Equipment for loan to school districts in emergency cases of breakdown or failure of district-owned equipment.
(4) Equipment for use in educational services.