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.
(December 2013) A transmission control unit or TCU is a device that controls modern electronic automatic transmissions. A TCU generally uses sensors from the vehicle as well as data provided by the engine control unit (ECU) to calculate how and when to change gears in the vehicle for optimum performance, fuel economy and shift quality.