| 摘要 |
Disclosed is a flow rate measuring apparatus capable of accurately measuring a mass flow rate of an exhaust gas. In a flow rate measuring apparatus (1), a laser distributor (40) causes a sheet-like laser to make one round trip in a laser introduction duct (20). An imaging device (50) takes first to eighth images at the exposure time of T/2n while synchronizing a timing of taking the images with T/n. A processor (90) calculates, based on the first to eighth images of continuous two periods, motion vectors of an exhaust gas for a period T at a plurality of positions in each image, averages the motion vectors into one motion vector, calculates the Y-components of the averaged motion vectors in the first to eighth images as movement amounts (By1 to By8) of the exhaust gas, calculates an arithmetic mean of the movement amounts as a representative movement amount (B) of the exhaust gas, calculates an actual flow velocity (S) of the exhaust gas from the representative movement amount, calculates an actual flow rate (Qm) of the exhaust gas from the actual flow velocity, and calculates, based on the actual flow rate, a mass flow rate (M) of the exhaust gas. |
