Electrical or electronic apparatus and instruments, in particular, electrical or electronic devices including computers containing micro processors; display or signalling panels in this class; sensors for use in display or signalling panels in this class; sound emitting, recording, amplifying, reproducing and transmitting apparatus in this class; computer memories and recorded computer programs; computer print-outs in this class; printed circuits; audio-visual apparatus and counters in this class; detectors and data processing apparatus in this class; and electrical or electronic monitoring or regulating apparatus in this class