204 / | HD | CHEMISTRY: ELECTRICAL AND WAVE ENERGY |
193 | DF | APPARATUS {5} |
194 | DF | .~ Electrolytic {11} |
228.1 | DF | .~.~ With current, voltage, or power control means responsive to sensed condition {8} |
228.4 | .~.~.~ Fluid pressure sensing means {1} | |
228.5 | DF | .~.~.~.~> Gaseous fluid |