JPS63105034U - - Google Patents

Description

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing one embodiment of this invention, Fig. 2 is an example of an explanatory diagram of liquid level measurement, and Fig. 3 is an example of an explanatory diagram of liquid level measurement.
4 is an example of a comparator operating waveform, FIG. 5 is an example of a transmitted signal waveform, and FIG. 6 is a block diagram of a conventional ultrasonic level meter. In the figure, 1 is a transducer, 2 is a timing circuit, 3 is a transmission circuit, 4 is a switching circuit, 5 is a reception circuit, 6 is a measurement circuit, 7 is a clock circuit, 8 is a signal conversion circuit, 9 is a comparison circuit, 10 is a control circuit. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claim for Utility Model Registration] An ultrasonic transducer is installed in the air and intermittently emits ultrasonic waves that are continuous for the duration of the timing circuit output pulse signal toward the liquid surface, and receives reflected signals from the liquid surface. In an ultrasonic level meter that measures the liquid level from the bottom based on the ultrasonic propagation time, there is a first setting level provided within the measurement range and a second setting level provided at the liquid level higher than the first setting level. a comparator having a set level, outputting an identification signal when the liquid level decreases and becomes lower than the first setting level, and further outputting an identification signal when the liquid level increases and rises above the second setting level; ,
A control circuit operated by the comparator output and a timing circuit generating pulse signals of a plurality of durations by the control circuit output are switched to control the duration of the ultrasound emitted by the transducer. Ultrasonic level meter configured as follows.