초록 ▼

An ulrasonic liquid level measurement device is used to measure the depth of a flowing liquid in a channel using an ultrasonic transducer that is positioned out of contact with the liquid and above and directed toward the channel. An ultrasonic burst is directed toward the channel and the reflected

An ulrasonic liquid level measurement device is used to measure the depth of a flowing liquid in a channel using an ultrasonic transducer that is positioned out of contact with the liquid and above and directed toward the channel. An ultrasonic burst is directed toward the channel and the reflected echo from the surface of the liquid is returned and sensed by the transducer. The transit time of ultrasonic transmission and echo return is indicative of the liquid level. An adjustable discriminator is provided to specify a maximum liquid level in the channel and a minimum liquid level, which, typically is the floor of the channel. The maximum and minimum levels are adjustable to accomodate variable channel configurations and transducer mounting arrangements. Automatic adjustment is provided to compensate for different cable lengths which may be used to connect the ultrasonic transducer to the transducer driver and receiving section. Temperature compensation is provided to compensate for changes in ultrasonic transmission propogation through ambient air with temperature, and time variable gain amplification is provided to compensate for geometric spreading of reflected ultrasonic energy echo pulses and for air path absorption.

대표청구항 ▼

An ultrasonic level flow detector for measuring the depth of a fluid flowing in a channel comprising: ultrasonic transducer means mounted above said channel for transmitting ultrasonic signals toward said channel and for receiving reflected ultrasonic signals therefrom; receiving means for detecting

An ultrasonic level flow detector for measuring the depth of a fluid flowing in a channel comprising: ultrasonic transducer means mounted above said channel for transmitting ultrasonic signals toward said channel and for receiving reflected ultrasonic signals therefrom; receiving means for detecting ultrasonic signals received by said ultrasonic transducer means; echo signal registration means coupled to said receiver for registering the occurence of an echo signal; indicator means connected to said echo signal registration means for expressing the occurrence of said echo signal as an indication of fluid flow level; adjustable discriminator means connected to said echo signal registration means to provide a maximum level signal at a minimum signal transit and reflection time and a minimum level signal at a maximum signal transit and reflection time, and to gate said echo signal registration means to receive an echo signal only during the interval therebetween; and time dependent non-linear gain amplification means interposed between said echo signal registration means and said indicator means for non-linearily increasing amplication of said echo signal as an increasing function of elapsed time between occurrence of said maximum level signal and said echo signal.