Sulfur dioxide (SO2) is irritating to eyes, skin and respiratory system. Volcanic Smog (vog) is produced from SO2 gas and is a hazard in Hawaii. Scientists monitor SO2 emission rates at KÄ«lauea volcano. Gas Plume during the 1984 eruption of Mauna Loa, Hawaii blocks out the sun.
Control Unit (CU) A control unit (CU) handles all processor control signals. It directs all input and output flow, fetches code for instructions from microprograms and directs other units and models by providing control and timing signals.
Engine control unit. An ECU from a 1996 Chevrolet Beretta. An engine control unit (ECU), also commonly called an engine control module (ECM), is a type of electronic control unit that controls a series of actuators on an internal combustion engine to ensure optimal engine performance.