Optical sensors; electronic sensors for measuring presence of objects and physical properties of objects; optical-electric sensors; photoelectric sensors; acoustoelectric sensors; magnetic sensors; inductive sensors; capacitive sensors; light barriers for the detection of the presence of objects; reflection light barriers for the detection of the presence of objects; light sensors; trigonometric light sensors; light grids for monitoring spatial areas; light grids for surveying objects; light curtains for monitoring spatial areas; light curtains for surveying objects; distance measuring apparatus; optical distance sensors based on the principle of the time of flight of light pulses; color sensors; contrast sensors; luminescence sensors; radar sensors; inductive, magnetic or capacitive proximity sensors; electronic interface modules; electronic input/output modules; optoelectronic image processing apparatus, in particular for automation technology and safety technology; cameras; 3D cameras; 3D sensors; optical, electronic, optoelectronic, acoustoelectric, magnetic, inductive and capacitive instruments for securing spatial areas, hazardous sites and hazardous areas; optical scanning apparatus, in particular laser scanners, using a moving beam to scan defined surfaces and/or spatial areas; optical scanners, not including document scanners; laser scanners; security laser scanners; safety light barriers, namely, photoelectric presence sensors designed to protect against bodily harm or injury; safety light curtains, namely, photoelectric presence sensors designed to protect against bodily harm or injury; multi-beam safety light barriers, namely, to protect against bodily injury; electronic safety controllers for controlling industrial machines; electric safety switches; electronic safety switches; safety controllers for security technology monitoring of installations and machines, in particular in the industrial sector; electronic position and length measuring instruments; electronic positioners, namely, electronic position sensors; rotary angle sensors; optical or magnetic angle encoders; rotating incremental encoders; rotating absolute encoders; incline sensor; motor feedback systems comprising a rotary angle encoder; code readers, in particular barcode readers; readers for two-dimensional codes and colour code readers; RFID-readers; spectrometers; gas analyzing apparatus, namely, residual gas analyzer, exhaust gas analyzer, trace gas analyzer, extracitve gas analyzer, in-situ gas analyzer, continuous gas analyzer, FTIR gas analyzer, NDIR gas analyzer, IR gas analyzer