Tier-1 certification kit with power meter and light source, compatible with multiple duplex and multi-fiber connectors up to 24 fibers. Measures loss, length, and polarity in just 1 second, as per certification standards. Power meters are a toolbox essential for all technicians installing or maintaining any type of fiber networks. An optical power meter (OPM) is a type of electronic test device used to measure the power output of fiber optic equipment or the power or loss of an optical signal transmitted through a fiber cable. An OPM uses a photodiode to generate an electrical current proportional to optical power.