| 摘要 |
PURPOSE:To offer a measuring apparatus measuring absolute humidity electrically, by using as the action principle that a dielectric constant of the atmosphere is varied with the existence of water vapor. CONSTITUTION:The output frequency of a microwave oscillator 1 is discriminated with respect to its frequency by a frequency discriminator 4 and is outputted into an output terminal 5 after converting said frequency to the imtermediate frequency by a harmonic converter 3 using a higher harmonic of a crystal oscillator 2 because the oscillation frequency of the oscillator 1 is varied with the specific inductive capacity of air. This output signal may be an analogue voltage value or digital pulse row. In this manner, the measurement having good linearity is made possible because the variation of steam pressure is connected primarily with the frequency variation. |
