| 摘要 |
PURPOSE:To make it possible to obtain an accurate flow rate without lowering measuring accuracy even to a small flow meter, by detecting inductance change with the rotation of the rotor of a flow meter as the change of high oscillation frequency. CONSTITUTION:When a fluid to be subjected to the measurement of a flow rate flows through a non-circular gear type flow meter 2, rotors 4, 5 are rotated in the number of rotations proportional to the flow rate thereof and the magnetic resistance of a magnetic circuit and the Q-value of a tank circuit 10 are cyclically changed in the frequency proportional to the number of rotations of the rotors 4, 5. Because the low frequency of the voltage wave in the tank circuit 10 is an approximate sine wave having the frequency proportional to the flow rate, it is detected by a detector circuit 14 and converted to a rectangular wave pulse by a wave form shaping circuit 15 while the rectangular wave pulse is counted by a counter 16 to make it possible to determine the flow rate. |
