| 摘要 |
PROBLEM TO BE SOLVED: To provide a signal processing apparatus, capable of always measuring with a constant precision even in the presence of the temperature change of a fluid to be measured, the mixing-in of bubbles and the rapid change from gas to liquid, having a high filtering capacity, and capable of performing a phase measurement with reduced computational complexity. SOLUTION: The Coriolis flowmeter for obtaining the mass flow rate and/or density of the fluid to be measured by detecting a phase difference and/or vibration frequency proportional to a Coriolis force with a velocity sensor or an acceleration sensor by alternately driving with a driving device at least one or a pair of flow tubes composing a flow tube for measurement is configured of, a transmitter 90 for transmitting a modulable frequency signal, a frequency converter 85 for controlling the transmitter 90 so that the frequency value becomes constant by performing a frequency conversion by adding (or subtracting) the output frequency F<SB>x</SB>of the transmitter 90 to an input signal detected by an electromagnetic pick-off, and a phase difference measurement unit 95 for performing the phase difference measurement of the frequency signal output from the frequency converter 85. COPYRIGHT: (C)2010,JPO&INPIT |
