| 摘要 |
PURPOSE:To enable a measurement of a gas flow with high precision relatively easily through short-period operation by taking a flow measurement of a reference work and then by taking a flow measurement of a valve, etc., to be measured under the same conditions to detect the difference between the both. CONSTITUTION:Gas from gas source 11 is reduced in pressure by reduction valve 12 and alternately supplied to reference work 21 and valve 14, etc., to be measured by on-off valves 22 and 23 after passing through the flow measuring means consisting of laminar pipe 15 and differential pressure detector 16. Valve 14, etc., to be measured having a nearly center flow rate is regarded as reference work 21 and in the alternating operation, the same gas communication resistance should be given. In this constitution, flow rate Qm of reference work 21 is stored in memory means 27 and the difference from flow rate Qw of valve 14, etc., is detected by difference detecting circuit 29; and the deviation DELTAQ is indicated by deviation indicator 31 and the correct flow rate of valve 14, etc., is indicated on indicator 34 through arithmetic circuit 33. Consequently, the errorneous difference is canceled by subtracting the difference according to measurement condition, so that high precision can be obtained. |
