Scientific, nautical, surveying photographic, cinematographic, optical, weighing, measuring, signalling, checking (supervision), life-saving and teaching apparatus and instruments, in particular encoders, optical encoders, magnetic encoders, incremental encoders, sine encoders, absolute encoders, end-shaft encoders, shaft encoders, hollow shaft encoders, cone shaft rotary encoders, single-turn encoders, multi-turn encoders, encoders with interface, fibre-optic light guides, encoders with high shock resistance, encoders with high vibration resistance, shaft encoders with clamping flange, shaft encoders with synchro flange, speed switches, encoder combination in particular encoders with tachogenerators with speed switch; electric speed switches; electric acceleration sensors; electric counters, tachometers; spindle positioning systems consisting of a drive unit combined with a measuring instrument, in particular a rotary encoder, actuators having electronic control loops, format alignment sensors; magnetic electronic sensors for linear and rotary applications; automated process control system, namely, micro-processor based hardware and software used to monitor the status of industrial machinery, namely, tachogenerators, tachogenerators without bearing, end shaft tachogenerators, shaft tachogenerators, cone shaft tachogenerators, tachogenerators with housing with internal bearing, tachogenerators with high shock resistance, tachogenerators with high vibration resistance; electrical resolver, electrical shaft resolver, electrical hollow shaft resolver; electric inclination sensors