The Transit Time Difference Ultrasonic Gas Meter - A Reassessment

摘要

When fiscal ultrasonic gas meters first came to market, about 1988 (Ref 1), they held great promise with claims like: 1) No moving parts. 2) No obstruction to the flow. 3) No pressure loss. 4) No calibration required. 5) Large turndown ratio. 6) Bi-directional flow measurement. 7) Velocity measurement independent of gas properties. 8) Installation requires minimal pipe work. 9) No periodic maintenance required. 10) Long life and stability. It seems appropriate after 15 years to pose the questions -