Optical smoke detector

Optical smoke detector circuit

Optical smoke detector improvements

Optical smoke detector with active self-monitoring

Optical smoke detector with conical light beam source

Optical smoke detector with scattered light collecting elements

Optical smoke detectors

Optical system for ceiling mounted passive infrared sensor

Optically biased smoke detector

Optics for infrared intrusion detector

Opto-electronic security fence

Optoelectronic device assembly mounted to bathroom equipment

Optoelectronic displacement sensor

Orientation line in an endless travelling web

Overhead warning device

Overheat detection sensor

Overload warning apparatus for internal combustion engines

Overstep recording device