Portable Ultrasonic Gas Flow Meter The portable ultrasonic gas flow meter uses ultrasonic technology to deliver high-precision gas flow measurement, operating on the principle of time-of-flight difference between upstream and downstream ultrasonic signals (typical accuracy: ±1%). In flowing gas, ultrasonic waves travel faster in the downstream direction (e.g., +2 m/s) and slower upstream (e.g., –2 m/s). A microprocessor calculates this time difference to derive flow velocity (measurable range: 0.1–60 m/s). Instantaneous flow rate (up to 10,000 m³/h) is obtained by multiplying velocity by the pipe’s cross-sectional area, and the meter also supports totalized flow accumulation. Its clamp-on, non-invasive design causes no pressure loss, and its compact, lightweight form (<5 kg) facilitates rapid field deployment—ideal for natural gas audits and industrial stack emission monitoring.