| 摘要 |
PURPOSE:To variably control a level of a transmitting pulse signal, by a method wherein an output element of a final stage output amplifying circuit in a transmitting part forms as electric field effect transistor, and an operation voltage is variably controlled. CONSTITUTION:A pulse signal Po is transmitted to one end 2A of a transmission 2 which is constituted such that it is installed along a liquid conveying line and characteristic impedance is caused to change partially by means of leak liquid, and a condition of a leak spot 3 is observed by means of a reflection wave PT thereof. A transmitting part 5 for transmitting the pulse signal Po is constituted such that an output element of a final stage output amplifying circuit sonsists of an electric field effect transistor Q8, and the level of the transmitting pulse signal Po is variably controlled by variably controlling the operating voltage -V of the final stage output amplifying circuit based on a receiving output of a receiving part 6. |
