| 摘要 |
PURPOSE:To obtain the highly sensitive mass flowmeter having a simple constitution, by constraining the position of a pipe, which becomes a node of a Coriolis vibration mode through an elastic member. and approximately agreeing the natural frequency of a driving mode with the natural frequency of the Coriolis vibration mode. CONSTITUTION:The central part of a U shaped pipe 1, which is to become the node of the Coriolis vibration mode (the vibration mode expressed by a Coriolis force, in this case torsional vibration, i.e. asymmetrical flexible vibration), is constrained by a spring 7. The other end of the spring is fixed to a base 3. In this consitution, the displacement of the U shaped pipe 1, generated by the Coriolis' force, is amplified and displayed by Q of the Coriolis vibration mode. Therefore the detecting sensitivity is improved to a large extent. When the driving frequency is made to agree with the natural frequency, phase difference is not generated between the on going path and the returning path of the pipe 1, but the difference in amplitudes is generated. In this case, the mass flow rate can be obtained by measuring the differnce in the amplitudes. |
