Flow measurement device

A flow measurement device comprising:

• a pair of vibrators being placed in a flow path where a measured fluid flows for transmitting and receiving an ultrasonic wave;
• a transmission device for driving one vibrator;
• a reception unit for converting an output signal of the other receiving-side vibrator into an electric signal;
• a reception wave determination unit for outputting a signal when the signal of said reception unit becomes a predetermined value;
• a reception point detection unit for outputting a signal when the signal of said reception unit becomes a predetermined range;
• at least two reception point storage units for storing output of said reception point detection unit;
• a time count unit for counting the propagation time of an ultrasonic wave signal propagating between said vibrators using each signal of said reception point storage units;
• a flow rate computation unit for calculating the flow rate based on the time count difference of said time count unit;
• and
• a control unit for controlling at least one of said transmission unit, said reception unit, said reception wave determination unit, said reception point detection unit, said reception point storage units, said time count unit, and said flow rate computation unit.