| 摘要 |
PROBLEM TO BE SOLVED: To solve the problem wherein errors occur, if the temperature of a sensor tube varies and the elastic coefficient is varied. SOLUTION: A flow rate measurement control circuit 400 includes an intrinsic safety barrier circuit 420, an excitation circuit 440, an integration circuit 460, a flow rate signal generation section 470, and an oscillator 510. The flow rate measurement control circuit 400 includes a barrier circuit 520, into which a temperature signal T detected by a temperature sensor 210 is input, a temperature measurement circuit 530, and a Young's modulus arithmetic circuit 540. Based on the amplitude L2, obtained by the integration circuit 460 and the frequency of a timing signal t1 input from the oscillator 510, the excitation circuit 440 outputs a driving voltage V of an oscillation frequency, other than the natural frequency of the sensor tubes 140 and 150 to an excitation coil 160a of a vibrator 160. The drive voltage V from the excitation circuit 440 is input into the excitation coil 160a, at a vibrating frequency (oscillation frequency other than the natural frequency) of a timing signal t1 from the oscillator 510. COPYRIGHT: (C)2011,JPO&INPIT |
