CN2100612U

CN2100612U - Sonar levelmeter

Info

Publication number: CN2100612U
Application number: CN 90209099
Authority: CN
Inventors: 王定华
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-06-26
Filing date: 1990-06-26
Publication date: 1992-04-01

Abstract

The utility model is called a sonar liquid level meter. The liquid level height of the liquid in the container is measured from the outside of the container by using the sonar principle; through an intermittent oscillation, the super audio oscillation signal whose duration is very short is generated periodically; the oscillation signal is sent to a probe for ultrasonic emission and reception; the oscillation signal is changed into the ultrasonic; the supersonic flow is emitted from the bottom wall of the container along the free upper surface direction vertical to the liquid, and the reflected ultrasonic is received; the reflected ultrasonic is changed into the corresponding electrical signal; a liquid level height measurement display device is used for measuring the time interval between the ultrasonic signals which are respectively reflected back by the upper surface and the lower surface of the liquid in the container to get measurement of liquid level height in the container.

Description

Sonar levelmeter

The utility model relates to the level gauging instrument, more particularly, relates to a kind of sonar formula liquid level gauge.

At present the liquid level of using in respect of cannula type liquid level gauge and float-ball type etc. several, the cannula type liquid level gauge is the height that inserts a glass tube Direct observation liquid level position on container.Float-ball type is then adorned a metal hollow ball float in container, float on the height of the ball float on the liquid level from the container external observation by connecting rod machinery.Existing these liquid level gauges all have a common shortcoming, promptly all will perforates on chamber wall, and this will influence sealing and may cause the leakage of seasoning at liquid in container.This is under the situation of pressure vessel, and it is more serious that problem just seems, because the pressure in the pressure vessel may be up to tens even the hundreds of atmospheric pressure, perforate causes stress to concentrate, and seriously has influence on the security and the reliability of high pressure vessel.

The purpose of this utility model is exactly the measurement that will realize under need not the situation of perforated container the liquid in container liquid level.This has guaranteed sealing, security and the reliability of container, particularly pressure vessel.

The utility model is to utilize sonar principle to come the height of liquid level in the measuring vessel, by a squegger, periodically produces a very short supersonic frequency (s.f.) oscillator signal of extended period; This oscillator signal is delivered to a ultrasonic emitting, receiving transducer, it converts this oscillator signal to ultrasound wave, from the diapire upper edge of container perpendicular to the direction emission ultrasound wave of the free upper surface of this liquid, and receive reflection ultrasound wave, convert thereof into corresponding electric signal; With liquid level measure display device measure the ultrasonic signal that reflects by the liquid in containers upper surface and said supersonic frequency (s.f.) oscillator signal or and the ultrasonic signal that reflects by the lower surface of liquid in containers and vessel bottom wall boundary between the time interval, measure thereby draw of liquid level in the container.

The utility model also utilizes of being installed in the container to calibrate the reading of liquid level gauge from the calibrating installation of vessel bottom wall fixed distance and correcting probe that is positioned at its lower reservoir bottom wall outer, so that at the accurate reading that obtains liquid level under different types of liquid, under different temperature.

This sonar formula liquid level gauge can be used to replace the various liquid level gauges of use now, and installation and use are very simple, convenient.This sonar formula liquid level gauge can be used powered battery, and required voltage is low, and power consumption is little, can not strike sparks, thus be specially adapted to store the level gauging of flammable liquid container, safe in utilization.It is 10 that whole components and parts are all selected crash rate for use ^-6Hour ^-1The components and parts that the order of magnitude is following, install and use after strict burn-in screen, when being installed on the pressure vessel, probe, probe feeder line all are contained in the betal can, the entire circuit device is contained in the sealing metal box, can make surpass 10 year or more the average life of this liquid level gauge like this.

By following description with reference to accompanying drawing, purpose of the present invention, feature and advantage will become more obvious.

Fig. 1 is the block schematic diagram of sonar formula liquid level gauge of the present utility model, and the principle of work of this liquid level gauge has been described.

Fig. 2 has represented the oscillogram at each point place among Fig. 1.

Fig. 3 is the part amplification profile of Fig. 1, has represented to be installed in the calibration device in the container.

Fig. 4 has represented an embodiment of liquid level measurement display device among Fig. 1.

Fig. 5 has represented another embodiment of liquid level measurement display device among Fig. 1.

With reference to Fig. 1, after energized, squegger (is seen " UT (Ultrasonic Testing) technology and defectoscope ", National Defense Industry Press, in September, 1977,274 pages of Fig. 4-57) periodically produce a very short supersonic frequency (s.f.) oscillator signal 01 of extended period, its oscillogram is shown in A in the accompanying drawing 2.Extended period τ is very short in vibration, and about for example about 1 microsecond, it depends on the height of minimum measuring liquid level, and the cycle of interrupted oscillation is longer, and for example about 20 milliseconds, it is relevant with the height of highest measurement liquid level.Under the measurement state, this supersonic frequency (s.f.) oscillator signal is amplified after calibration/measurement switch K delivers on ultrasonic emitting, receiving transducer (see and the ibidem the 218-220 page or leaf) S1 by amplifier (see and ibidem 250 pages of Fig. 4-31), probe S1 converts this supersonic frequency (s.f.) oscillator signal to ultrasound wave and injects container from the bottom wall outer of container, and it injects direction, and should to be adjusted to roughly on the freedom with liquid liquid level vertical.

Each ultrasonic pulse can produce reflection on the interface of vessel bottom wall and liquid, the ultrasonic pulse of reflection converts a supersonic frequency (s.f.) electric oscillation signal 02 to after being received by probe S1, appears at the B point place of Fig. 1.Equally, also can cause reflection by the pulse of probe S1 ultrasonic waves transmitted on the interface of liquid-to-air above the container, form another reflection wave, this reflection wave is popped one's head in after the S1 reception, convert another supersonic frequency (s.f.) electric oscillation signal 03 to, also appear at the B point place of Fig. 1.So for each supersonic frequency (s.f.) oscillator signal 01 that squegger produces, 3 supersonic frequency (s.f.) oscillator signals successively appear in the place at the B of accompanying drawing 1 point, they are shown in B among Fig. 2.The time interval t of 02 of first oscillator signal 01 and second oscillator signal wherein ₁Being ultrasound wave vertically propagates into 2 times of inside bottom wall time from the container bottom wall outer, and the time interval t between second oscillator signal and the 3rd oscillator signal ₂It is exactly ultrasound wave propagates into the liquid upper surface elapsed time from the container inside bottom wall along vertical liquid level direction 2 times, because the velocity of propagation of ultrasound wave in a certain liquid is constant, so time t ₂Be directly proportional with the liquid level h1 among Fig. 1, promptly it is that of liquid level measures.The squegger output signal at Figure 1A point place triggers a monostable circuit and (sees and ibidem 247-248 page or leaf Fig. 4-27, Fig. 4-28), produce the rect.p. that a pulsewidth is slightly larger than supersonic frequency (s.f.) oscillator signal extended period τ, the supersonic frequency (s.f.) oscillator signal that utilizes this rect.p. to go to block squegger output enters the level gauging display device.For example, can make an AND circuit (see and ibidem 249 pages of Fig. 4-29 with this rect.p., 251 pages of Fig. 4-32) close the time that is slightly larger than τ, thereby stoped among Fig. 2 B first oscillator signal 01 by with door, allow second and the 3rd oscillator signal 02 and 03 by AND circuit, enter the level gauging display device, so that measure the time interval between these two oscillator signals, measure as of liquid level.Obviously, if can ignore the error that vessel bottom wall thickness brings, also can be by measuring the time interval between first oscillator signal 01 and the 3rd oscillator signal 03, measure as of liquid level.The output of monostable circuit can also be delivered to the level gauging display device as reset signal, and the echoed signal that each supersonic frequency (s.f.) oscillator signal that it is produced squegger produces is carried out one-shot measurement.

The level gauging display device can adopt oscillographic form (see and ibidem 244 pages of Fig. 4-22,246 page Fig. 4-25,247 page Fig. 4-26), the indication of obtaining liquid level by the time interval that shows two signals on video screen.Adopting battery powered liquid crystal display oscillograph is a kind of preferred form, also can be used as the level gauging display device with time interval numeric display unit, Fig. 4 has provided this specific embodiment and (has seen " circuit design of electronic device ", Science Press, in September, 1986, page Fig. 5-20,123 page of figure of 338 pages of Figure 17-17,247 page Figure 12-6,96 E-3).The signal triggering bistable circuit at C point place among Fig. 1 produces the time interval t between second, third oscillator signal on a pulse width and Fig. 2 B ₂The rect.p. that equates is in this pulse width time, with door conducting t ₂The time, the counter pulse that multivibrator is produced passes through to be somebody's turn to do and door, is counted the count results of counter and said time interval t by counter ₂, thereby just liquid level h1 be directly proportional, thereby be that of liquid level measures.A digital indicator carries out numeral to the count results of counter and shows that directly the form with liquid level provides demonstration.Require the frequency ratio of multivibrator more precise and stable.

In addition, also can carry out pointer-type to liquid level and show (see before " UT (Ultrasonic Testing) technology and defectoscope ", 274-275 page or leaf Fig. 4-59, Fig. 4-60), Fig. 5 has represented such specific embodiments.Obviously, the output of bistable circuit is that, pulsewidth identical with the squegger output signal cycle of a series of cycles equals time interval t ₂Rect.p., its DC component is directly proportional with pulsewidth, therefore, the indication of D.C. voltmeter is exactly that of liquid level measures among Fig. 5.

Because the velocity of propagation of ultrasound wave in liquid is relevant with kind, the temperature of liquid, can accurately indicate the liquid level of variety classes liquid in order to make this liquid level gauge under different temperatures, this liquid level gauge is provided with a calibrating installation.Before each this liquid level gauge of use, should calibrate earlier.Referring to accompanying drawing 3, a calibration sylphon 4 that is fixed on the support 5 is arranged in the container, one of vessel bottom wall arranged outside and the duplicate calibration probe of probe S1 S2 over against its below, in this sylphon air is arranged, and seal, its lower surface 6 is very thin, for example is about 0.2 millimeter, so that can disregard the influence of its thickness at timing.This lower surface highly precisely equals an altitude datum l apart from container bottoms, and for example l is 20 centimetres exactly.During calibration, to calibrate/measure switch K earlier and forward calibrating position to, the output of squegger is amplified after K delivers on the calibration probe S2, and situation about describing during to measurement is similar, and at this moment the level gauging display device will demonstrate the height of this calibration sylphon lower surface apart from vessel bottom wall.The frequency that the regulator potentiometer W of multivibrator regulates count pulse among adjusting Fig. 4, make digital indicator accuracy of reading equal altitude datum l, under situation about showing with oscillograph, can regulate the gain of oscillographic horizontal amplifier, make the recurrent interval of indicating equal altitude datum l exactly with liquid level unit.Under the pointer-type indication situation of Fig. 5, can make the pointer indication equal altitude datum l exactly by the amplitude of regulating bistable circuit output pulse.

Because container in actual use, often can not keep substantially horizontal position, cause in the container liquid level everywhere unequal.In order to measure the liquid level at diverse location place, also a plurality of ultrasonic emitting, receiving transducer can be set, the situation of two measuring sondes (S1, S3) has been shown among Fig. 1.By rotating calibration/measurement switch, just can make things convenient for, promptly measure the liquid level (as h1 and h2) at each measuring sonde place.

Below in conjunction with the accompanying drawings the explanation of the utility model specific embodiment just is used for showing invention, rather than to restriction of the present utility model, scope of the present utility model is limited by appending claims.

Claims

1, a kind of sonar formula liquid level gauge is made up of squegger, amplifier, monostable circuit, AND circuit, level gauging display device and ultrasonic emitting, receiving transducer S1, it is characterized in that: squegger is connected with amplifier and monostable circuit; Amplifier connects to ultrasonic emitting, receiving transducer S1 and AND circuit; Monostable circuit connects to AND circuit and level gauging display device; Ultrasonic emitting, receiving transducer S1 are positioned at the outside of vessel bottom wall, and its transmit direction is vertical with the free upper surface of liquid.

2, by the described a kind of sonar formula liquid level gauge of claim 1, it is characterized in that: the level gauging display device can be one of following three kinds of forms: (1) oscillograph (time interval that shows two signals on video screen); (2) time interval numeric display unit; (3) dial indicator display device of bistable circuit and D.C. voltmeter composition.

3, by claim 1 or 2 described a kind of sonar formula liquid level gauges, it is characterized in that: a calibration sylphon 4 that is fixed on the support 5 is arranged in container, in air arranged and seal, its lower surface 6 very thin (0.2 millimeter), its lower surface 6 highly precisely equals an altitude datum l apart from container bottoms; One of vessel bottom wall arranged outside below calibration sylphon 4 and ultrasonic emitting, the duplicate calibration probe of receiving transducer S1 S2; Has calibration/measurement switch K in addition.