| 422 / | HD | CHEMICAL APPARATUS AND PROCESS DISINFECTING, DEODORIZING, PRESERVING, OR STERILIZING |
| 50 | DF | ANALYZER, STRUCTURED INDICATOR, OR MANIPULATIVE LABORATORY DEVICE {11} |
| 83 | DF | .~ Means for analyzing gas sample {6} |
| 94 | DF | .~.~ Combustible gas detector {1} |
| 95 | DF | .~.~.~ With thermoelectric detector {1} |
| 96 | | .~.~.~.~ Wheatstone bridge {1} |
| 97 | DF | .~.~.~.~.~> With specific coating on bridge element |