A water-injection control system is disclosed for a water supersaturation system installed in a gas turbine air intake system for augmenting gas turbine power output during operation at high ambient-air temperature, while maintaining the water content in the intake air within limits acceptable to the gas turbine as indicated by measured gas turbine operating parameters. The gas flow is subjected to a dry cleaning using at least one dry filter, wherein dusts andor fine particulate raw materials are separated from the gas flow. The cap is for developing a seal around the ink ejection surface of the head. Each signal transmission line is coated with an insulating layer.