| 700 / | HD | DATA PROCESSING: GENERIC CONTROL SYSTEMS OR SPECIFIC APPLICATIONS |
| 90 | DD | SPECIFIC APPLICATION, APPARATUS OR PROCESS {16} |
| 266 | DD | .~ Chemical process control or monitoring system {6} |
| 274 | | .~.~ Control of combustion or heating apparatus (e.g., kiln, furnace, autoclave, burner, combustion system) |