| 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 | DF | .~.~.~ Fluid pressure sensing means {1} |
| 228.5 | | .~.~.~.~ Gaseous fluid |