| 摘要 |
PURPOSE:To obtain the cut-off frequency with high accuracy, by measuring three consecutive resonance frequencies. CONSTITUTION:The resonant wave number and measured waveguide length are erased from three consecutive resonance frequencies fr1, fr2, fr3 and the equation of in-tube wavelength, resonant wavelength and cut-off wavelength, and the cut-off frequency fc is obtained with equation. Thus, the objective measuring value can be obtained independently of the items of the length of waveguide length and resonant wave number. |
