power line monitoring systems; power distribution apparatus for use in electrical systems; power supply units being scientific apparatus; digital control apparatus for power units; power generation monitoring apparatus; sensors (measurement apparatus), other than for medical use; process control units using process control computers; devices for system load control; microprocessor based control systems for use with machine tools; precision sensors being parts electronic control apparatus; energy control devices; electronic process control units; process control units (electronic); electrical control apparatus being computer operated; apparatus for monitoring electrical components; apparatus for controlling the supply of electrical current; microprocessor-based control systems for use with machine tools; remote control devices for industrial operations (electric or electronic); electrical power supply apparatus (other than generators); electronic instruments for the measurement of electrical parameters; machines for monitoring the accuracy of metering apparatus; monitoring control apparatus (electric); apparatus for monitoring electronic components; apparatus for use in testing communication channels; electronic industrial network apparatus for high speed data transmission; electrical data input apparatus for use with computers; electronic control installations for sensors; electronic instruments for monitoring systems in buildings; apparatus for use in fuel measurement; electronic instruments for the measurement of process parameters; electrical apparatus for converting signals into visual information; electronic testing instruments for testing electrical systems; digital direct current power supplies; microprocessor driven control units for automatic control systems; indicators for the optical monitoring of pressure of gases; computer controlled automatic testing apparatus; electrical process control instruments; automatic test instruments for monitoring telephone lines; power modules for sequential control; electric mains monitoring devices; control units for use in electronic key telephone installations; measuring apparatus for use in beverage quality control; power units for supplying (other than generating) electrical current; dynamic filters for use in the control panels of fire detection systems; electrical converters for controlling access to premises; numerical control systems for machine tools; apparatus for monitoring picture quality parameters of video signals; manual controlled signal storage units; alarm systems incorporating control and visual display apparatus; audio signal level controlling apparatus; electrical switching for monitoring devices; electronic digital controllers for controlling digital flow control valves; power sources connected to audio apparatus for use in motor vehicles; electrically powered apparatus controlling the specific gravity of solutions used in printing; measurement apparatus for well testing; checking apparatus having measuring capabilities; digital electrical gauges adapted for use in controlling air pressure; precision sensors being parts of alarm systems; computer based development apparatus for testing electronic circuits; apparatus for sound level measurement; differential pressure transmitters for measurement purposes; interface units for linking electronic store price scanners with system controls