Gas Ultrasonic Flow Meter — BF70-2
BF70-2 gas ultrasonic flow meter is designed specifically for gas — natural gas, compressed air and flue gas. Multi-path design improves accuracy; gas sound velocity varies with temperature and pressure, which the algorithm compensates for. Widely used for custody transfer in gas metering.
Specifications
| Media | Natural gas, compressed air, flue gas |
| Design | Multi-path (multi-channel) |
| Method | Transit-time with temperature/pressure compensation |
| Application | Gas trade / custody transfer metering |
| Output | 4–20mA, pulse, RS485 |
| Straight run | 10D upstream / 5D downstream |
Details
Working Principle
The transit-time principle: gas sound velocity is affected by temperature and pressure, and the algorithm compensates for the sound velocity so that mass/standard-volume flow remains accurate. Multi-path (multi-channel) sound beams improve accuracy and handle non-uniform velocity profiles, which is why it suits high-accuracy custody-transfer stations.
Performance Notes
Same ultrasonic family advantages: no moving parts, no pressure loss, cost-effective on large bores. For gas, the transducer coupling surface must be clean and the gas reasonably dry; wet or particle-laden gas degrades signal quality.