| 摘要 |
PURPOSE:To remove influences of the change of the propagating speed of microwaves upon a measuring value. CONSTITUTION:This monitoring apparatus is so adapted as to detect the storing amount by transmitting frequency-modulated microwaves towards a stored substance in the storing tank and receiving the reflected microwaves from the storing substance. A reference reflecting body is provided inside the storing tank to reflect the frequency-modulated microwaves. After the frequency component of a difference signal corresponding to the reflected wave is analyzed by a first frequency analyzing part 15, the storing amount of the substance is operated by a first storing amount operating part 16 from the ratio of the frequencies of the frequency component indicating the position of the reference reflecting body and the frequency component indicating the position of the reflecting surface of the substance based on the analyzing result. |
