| 摘要 |
PURPOSE:To measure accurately a flow rate of gas by letting the gas to be measured to act with a liquid surface of one side of fluid stored in a U-shaped pipe path by suitable amount and obtaining the accompanied pressure variation amount of the fluid. CONSTITUTION:Gas is supplied into a tank 4 through valves 2, 3 and liquid surface 7a and 7b in vessels 5 and 6 are nearly in the same level, and a differential pressure detector 8 outputs a signal of the value corresponding to some pressure value DELTAP1. If the valve 3 is closed, the gas flows in the direction of a dotted line arrow, the liquid surface 7b is raised and the value of the output signal S1 of the detector 8 is increased. The position variation amount of the surface 7b suggests the flow rate of the gas introduced in the vessel 5. Thus by obtaining the position variation amount of the surface 7b, i.e., the pressure variation amount, the flow rate of gas can be measured. A controller 9 detects time points when pressures detected by the detector 8 attain DELTAP1 and DELTAP2, and outputs signal S3 which closes and opens the valve 3 in terms T1, T2... and in terms T'1, T'2... respectively, and calculates the pressure variation in the terms T1, T2..., i.e., the amount of gas flowing in the vessel 5 basing on the signal S1 of the detector 8. |
