Type 55: Gravity bulk meters
| Subtype | Inclusions | Exclusions |
|---|---|---|
| 10 Uncompensated | Uncompensated gravity bulk meters. | Vehicle-mounted meters. |
| 11 Temperature compensated | Compensated gravity bulk meters incorporating ATC. | Vehicle-mounted meters. |
| 20 Vehicle-mounted uncompensated | Uncompensated vehicle-mounted gravity bulk meters. | - |
| 22 Vehicle-mounted temperature compensated | Vehicle-mounted gravity bulk meters incorporating ATC. | - |