- For liquids lighter than water
- Models 6025F10 through F20 are for testing small quantities
Models 6025C10 through C25 require a cylinder 340 x 38 mm diameter and approximately 250 mL of liquid for submersion. Models 6025F10 through F20 require a cylinder 150 mm deep x 25 mm i.d. and approximately 50 mL of liquid for submersion.
Thomas No. | Range | Interval | Tolerance | Approx. Total Length | Approx. Graduated Scale Length |
| 6025C25 | 0.700 to 1.000 | 0.005 | ±1 | 305 mm | 135 mm |
| 6025F10 | 0.700 to 0.800 | 0.002 | ±2 | 150 mm | 45 mm |
| 6025F15 | 0.800 to 0.900 | 0.002 | ±2 | 150 mm | 45 mm |
| 6025F20 | 0.900 to 1.000 | 0.002 | ±2 | 150 mm | 45 mm |