Surveying, measuring and signaling apparatus and instruments, namely, sensors for determining temperatures, positions and distances, liquid level sensors; industrial sensors, namely, optical, electronic, optoelectronic, photoelectric, acoustoelectric, magnetic, inductive and capacitive sensors, fibre-optic systems, position sensors, distance measuring apparatus, color sensors; apparatus and instruments for conducting, switching, transforming, accumulating, regulating or controlling electricity, namely, electric contactors, electrical controllers, electricity limiters, electric power supplies, lasers not for medical use, light conducting filaments, and time relays; apparatus for recording, transmission or reproduction of sound or images; data processing equipment and computers