Complex sentence: Reed switches actuated by magnets are commonly used in mechanical systems as proximity sensors, e.g. as door and window sensors in burglar alarm systems and tamperproofing methods (however they can be disabled by a strong, external magnetic field).
Split into simpler sentences: Reed switches actuated by magnets are commonly used in mechanical systems as proximity sensors. Examples are door and window sensors in burglar alarm systems and tamperproofing methods (however they can be disabled by a strong, external magnetic field).