The Transit Time Flowmeter utilises two transducers that function as both, ultrasonic transmitters and receivers. The transducers are clamped on the outside of a closed pipe or inserted in the pipeline by using an isolating ball valve assembly at a specific distance from each other. Transit Time Flowmeters measure the time it takes for an ultrasonic signal transmitted from one sensor to cross a pipe and be received by a second sensor. Upstream and downstream time measurements are compared. With no flow, the transit time would be equal in both directions. with flow, sound will travel faster in the direction of the flow and slower against the flow. The liquid velocity (V) inside the pipe can be related to the difference in time of flight (△ t) through the following equation:
| V | = | KxDx△t |
| where V | : | Liquid velocity |
| K | : | Constant |
| D | : | Distance between the two transducers |
| △t | : | Difference in time of flight |
| Power Supply | 24 V DC ± 20% 110 V AC ± 15% 240 V AC ± 15% |
| Velocity | ± 12 m/sec, Bidirectional |
| Display | 2 lines, 16 characters, LCD with backlight, flow rate velocity, totaliser |
| Units | User configurable English/Metric |
| Totaliser | FWD, NET, REV, BATCH (Gallons, ft³, Barrels, lbs, m³) |
| Output | 4-20 mA DC Std.* |
| Accuracy | ± 1% of reading @ ate > 0.5 m/sec. (Optional ± 0.5% of reading) |
| Repeatability | 0.2% of Span |
| Dimensions | 251x190x96 mm |
| Weight | < 2.5 kg |
| Security | Keypad lockout, access code enabled |
| Suited temp. - Std. | -40°C to 120°C | |
| Suited temp. - High | -40°C to 250°C | |
| Pipe Size | S Transducer | 15-80 mm |
| M Transducer | 50-700 mm | |
| L Transducer | 400-4570 mm | |
| Dimensions | S Transducer | 45x30x30 mm |
| M Transducer | 60x45x45 mm | |
| L Transducer | 80x70x55 mm | |
| Weight | S Transducer | < 0.3 kg |
| M Transducer | < 0.5 kg | |
| L Transducer | < 1.0 kg | |
| Cable length | 6 m Std. can be extended up to 300 m | |
| Flexible belts | SS belt according to pipe size | |
| Portable case | NA | |
