PROBLEM TO BE SOLVED: To provide a fluid evaluation device that suitably calculates at least one of the flow rate and the flow velocity of a fluid while taking the concentration of the fluid into account.SOLUTION: A fluid evaluation device 1 comprises irradiation means 11 for irradiating a measurement object 100 inside of which a fluid is flowing with a laser beam LB, light-receiving means 12 for receiving the laser beam radiated to the measurement object and generating a light-receiving signal, and calculation means for calculating the flow velocity of the fluid, the calculation means calculating a flow velocity so that, under a situation where frequency changes of the light-receiving signal caused by the Doppler shift of the laser beam radiated to the measurement object are the same, a flow velocity that is calculated when the concentration of the fluid is low is smaller than a flow velocity that is calculated when the concentration is high.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】流体の濃度を考慮しながら流体の流量及び流速の少なくとも一方を好適に算出する流体評価装置を提供する。【解決手段】流体評価装置1は、内部に流体が流れている被測定対象100に対してレーザ光LBを照射する照射手段11と、被測定対象に照射されたレーザ光を受光して受光信号を生成する受光手段12と、流体の流速を算出する算出手段とを備え、算出手段は、被測定対象に照射されたレーザ光のドップラシフトに起因する受光信号の周波数変化が同一である状況下において、流体の濃度が低い場合に算出される流速が、濃度が高い場合に算出される流速よりも小さくなるように、流速を算出する。【選択図】図1
