JPS6184524U - - Google Patents

Description

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a liquid level measuring section according to this invention, FIG. 2 is a circuit diagram showing an embodiment of a liquid level measuring circuit connected to the liquid level measuring section in FIG. 1, and FIG. Fig. 3 is a time chart of the liquid level measuring circuit shown in Fig. 2, Fig. 4 is a sectional view showing a conventional liquid level measuring section, and Fig. 5 is a circuit connected to the liquid level measuring circuit shown in Fig. 4. Circuit diagram showing the liquid level measurement circuit, No. 6
The figure is a time chart of the conventional liquid level measuring circuit shown in FIG. 1...Tank, 2...Liquid, 3...Ultrasonic transmitting/receiving element, 5...Correction reflector, 22...Pulse oscillator, 2
3... Gate signal generation circuit, 24... AND gate,
25, 26...Latch circuit, 27, 28...and
Gate, 29, 30... Time calculation unit, 31... Reference pulse oscillator, 32... Amplification/detection circuit, 33... Waveform shaping circuit, 34, 35... Counter circuit.

Claims (1)

[Scope of utility model registration request] An ultrasonic transmitting/receiving element 3 that is attached above or below the surface of the liquid 2 stored in the tank 1 and transmits and receives ultrasonic waves from one vibration surface; and the ultrasonic transmitting/receiving element. A correction reflector plate 5 is provided at a position between the liquid level and outside the liquid level fluctuation range and reflects a part of the ultrasonic waves from the ultrasonic transmitting/receiving element 3; Receiving element 3
Ultrasonic signal generation circuits 22, 23, 2 that generate ultrasonic waves by supplying signals with frequencies in the ultrasonic range to
4, and after the ultrasonic wave is transmitted, the ultrasonic wave is transmitted.
Waveform converting circuits 32 and 33 that convert the time-series reflected waves at the correction reflecting plate 5 and the liquid surface position received by the receiving element 3 into rectangular pulses; counter circuits 34 and 35 that output a first control signal when the first pulse is input and a second control signal when the second rectangular pulse is input; first and second time calculation circuits 2 that start counting clock pulses and stop the counting based on first and second control signals from the counter circuits 34 and 35;
5, 27, 29, 31 and 26, 28, 30, 3
1, and a liquid level calculation circuit 36 that calculates the liquid level based on the ratio of the respective times calculated by the first and second time calculation circuits, and an output of the liquid level calculation circuit. A liquid level measuring circuit characterized in that the signal is used as a liquid level signal.