| 73 / | HD | MEASURING AND TESTING |
| 53.01 | DF | LIQUID ANALYSIS OR ANALYSIS OF THE SUSPENSION OF SOLIDS IN A LIQUID {15} |
| 54.01 | DF | .~ Viscosity {11} |
| 54.04 | DF | .~.~ Friction tube (e.g., capillary) {3} |
| 54.05 | | .~.~.~ Plural tubes {1} |
| 54.06 | DF | .~.~.~.~> By pressure measuring |