JP2017120187A - Liquid level measuring probe, liquid level measuring system, and liquid level measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the lowermost end position of an outer peripheral surface of piping arranged horizontally and to measure the liquid level at the lowermost end position by ultrasonic measurement.SOLUTION: An ultrasonic probe 11 includes a probe surface 11a for radiating an ultrasonic wave and receiving a reflection echo, and outputs a reflection echo signal corresponding to the reflection echo. A gravity sensor 12 outputs a gravity detection signal with a value corresponding to gravity when a sensor axis 12a faces a vertical direction, and the value of the gravity detection signal reduces when the sensor axis 12a deviates from the vertical direction. A liquid level measuring probe 10 is formed by combining the ultrasonic probe 11 and the gravity sensor 12 in a state of the sensor axis 12a orthogonal to the probe surface 11a. When the value of the gravity detection signal becomes the largest, the liquid level is detected on the basis of the reflection echo signal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a liquid level measurement probe, a liquid level measurement system, and a liquid level measurement method, and accurately detects the liquid level of a liquid existing inside a structure such as a pipe from the outside of the structure using ultrasonic waves. It is devised so that it can be measured.

In factories and various facilities, a liquid level (water level) measuring device is used to detect the liquid level (water level) of a liquid (for example, water) existing inside a structure that contains liquid, such as pipes and tanks. ing. For example, as the current technology for measuring the water level in a pipe, there are the following.
-A method of measuring the water level by installing a float in the pipe and measuring the float's position change and buoyancy fluctuation.
・ A method that measures the pressure generated by water by installing a pressure detector in the pipe and measures the water level based on the measured pressure.
-A method of measuring the water level based on the measured change in electrical capacitance by installing a pair of electrodes in the pipe and measuring the change in electrical capacitance between the electrodes.
・ Install an ultrasonic probe on the outer peripheral surface of the pipe, detect the reflected echo reflected from the water surface by the ultrasonic wave emitted from the ultrasonic probe, and detect the water level based on the timing of detecting the reflected echo. (See Patent Documents 1 and 2).

Among these water level measurement methods, the water level measurement technology using an ultrasonic probe can measure the water level from the outside of a sealed pipe without the need to drill holes in the pipe or other structures. Therefore, there is an advantage that the water level (liquid level) can be easily detected.
For this reason, when detecting the water level existing in the horizontally arranged pipes at a number of inspection positions in the longitudinal direction of the pipes, the water level is measured using an ultrasonic probe. Yes. Specifically, at the first inspection position in the longitudinal direction of the pipe, the inspector manually brings the ultrasonic probe into contact with the outer peripheral surface of the pipe, measures the water level in this state, and finishes the water level measurement at this position. Then, the inspector manually repeats the operation of bringing the ultrasonic probe into contact with the next inspection position and measuring the water level in this state one after another.

  In this specification, “horizontal arrangement” means not only that the arrangement state of the pipes is completely horizontal, but also that the liquid can be retained inside the pipe although it is inclined to some extent. It is used to mean an arrangement state that also includes being arranged in the horizontal direction.

FIG. 7 shows an example in which the ultrasonic probe 1 measures the water level of the water W present inside the horizontally arranged pipes P. In this example, the pipe thickness of the cylindrical pipe P is T, and the water level of the water W is H.
The inspector brings the ultrasonic probe 1 into contact with the lowest end position of the outer peripheral surface of the cylindrical pipe P at a certain inspection position in the longitudinal direction of the pipe, and emits ultrasonic waves from the ultrasonic probe 1. To measure ultrasound. In the ultrasonic measurement, the emitted ultrasonic wave is reflected by the inner peripheral surface of the pipe P and returned, and the emitted ultrasonic wave passes through the pipe P to pass through the surface of the water W (liquid interface). ), The second reflected echo reflected back is obtained. The first reflected echo and the second reflected echo return repeatedly. For this reason, the water level H can be measured based on the time interval of the second reflected echo that repeatedly returns.

JP 2014-89142 A JP 2009-139212 A

  Incidentally, in order to accurately measure the water level of the water W existing inside the cylindrical pipe P, it is necessary to bring the ultrasonic probe 1 into contact with the lowest end position of the outer peripheral surface of the pipe P. In this way, the ultrasonic wave generated from the ultrasonic probe 1 is emitted vertically upward from the lowest position and proceeds in a direction perpendicular to the water surface, so that the water level is accurately measured. Can do.

However, as shown in FIG. 8, when the ultrasonic probe 1 is brought into contact with a position shifted from the lowest end position of the outer peripheral surface of the pipe P, the water level measurement error increases. For example, when the ultrasonic wave incident on the water W travels in an oblique direction with respect to the vertical direction, the measured water level may become higher than the actual water level.
As shown in FIG. 9, when the pipe P has a small diameter and a small amount of water, the water is not present, that is, the water level is erroneously measured as zero even though there is water W inside the pipe P. Sometimes. This is because the ultrasonic probe 1 is arranged so as to deviate from the lowermost position, and thus the emitted ultrasonic wave is not incident on the water W even though the water P is actually present in the pipe P.

When it is difficult to visually check whether the ultrasonic probe is positioned at the lowermost position on the outer peripheral surface of the pipe when a large number of pipes are arranged horizontally in a narrow space There is. In such a case, whether or not the ultrasonic probe is arranged at the correct position can be obtained by checking the waveform obtained by the ultrasonic flaw detector and the inspector when the ultrasonic probe is attached to the pipe. Judgment was made depending on the senses. Thus, depending on the sense of the inspector, there are problems that the measurement accuracy of the water level is lowered and the establishment of erroneous evaluation becomes very high.
Further, depending on the arrangement state of the pipe, the inspector may sink under the pipe, search for the lowermost position of the pipe, and attach an ultrasonic probe to the lowermost position. Thus, the work of searching for the lowermost position of the pipe is troublesome and takes time.

  Even in a tank having a bottom surface whose bottom surface is convex while gradually curving downward in the vertical direction, there is a problem similar to the problem in the above-described piping (see FIGS. 8 and 9).

  In view of the above-described prior art, the present invention provides a liquid level measurement probe, a liquid level measurement system, and a liquid that can easily and accurately detect the liquid level of a liquid existing inside a structure that contains liquid such as piping. The purpose is to provide a position measurement method.

The liquid level measurement probe of the present invention that solves the above problems is
An ultrasonic probe that has a probe surface that emits ultrasonic waves and receives reflected echoes, and a gravity sensor that outputs a gravity detection signal with a value corresponding to gravity when the sensor axis is oriented in the vertical direction. The ultrasonic probe and the gravity sensor are integrated in a state where the sensor axis is orthogonal to the probe surface.

The liquid level measurement system of the present invention is
It consists of the above liquid level measuring probe and a liquid level measuring instrument.
The liquid level measuring instrument is
The gravity detection signal is input from the gravity sensor, an extreme value among the detected gravity values is specified and stored as an extreme gravity value, and a trigger signal is output from the lowest end position detection unit and the ultrasonic probe. When a reflected echo signal corresponding to the reflected echo is input from the touch element, an ultrasonic waveform signal indicating an ultrasonic waveform is formed, and the ultrasonic waveform is displayed by the ultrasonic waveform signal. An ultrasonic measurement unit that holds the ultrasonic waveform signal when the trigger signal is input and continuously displays the held ultrasonic waveform;
A notification unit that performs a notification operation when the trigger signal is input;
It is characterized by comprising.

The liquid level measurement system of the present invention is
The ultrasonic measurement unit continuously displays the ultrasonic waveform when the trigger signal is input and the amplitude value of the ultrasonic waveform signal is larger than a predetermined threshold;
Further, the ultrasonic measurement unit has an input unit, and when the approval signal is input from the input unit, storing the held ultrasonic waveform signal,
The ultrasonic measurement unit holds the ultrasonic waveform signal when the trigger signal is input and the amplitude value of the ultrasonic waveform signal is larger than a predetermined threshold and the approval signal is further input. The ultrasonic waveform is continuously displayed by the held ultrasonic waveform signal.

The liquid level measurement method of the present invention is
The liquid level measurement probe measures the liquid level of the liquid containing the liquid by scanning the inspection surface that is gradually curved downward in the vertical direction and is convex. A way to
With the probe surface in contact with the outer surface of the inspection surface, the liquid level measurement probe passes through the lowermost position from a position higher than the lowermost position of the inspection surface and further passes the lowermost position. Scanning to a position, and specifying and storing an extreme value among the values of the gravity detection signal obtained at the time of scanning as an extreme gravity value,
In a state where the liquid level measurement probe is placed at a position where the value of the gravity detection signal becomes the extreme gravity value, an ultrasonic waveform signal is obtained from a reflected echo signal obtained from the ultrasonic probe, The liquid level of the liquid is measured based on a sound wave waveform signal.

  According to the present invention, when measuring the liquid level (water level) of a liquid (for example, water) existing inside a structure that contains liquid such as a pipe or a tank, the liquid level measurement probe is connected to the inspection surface of the structure. Of these, the liquid level can be easily arranged at the lowermost position, and the liquid level can be detected easily and accurately.

The block diagram which shows the water level measurement probe which concerns on the Example of this invention. The block diagram which shows the water level measurement system which concerns on the Example of this invention. Explanatory drawing which shows the state which measures a water level using the water level measurement system which concerns on the Example of this invention. Explanatory drawing which shows an example of the state which measures a water level using the water level measurement system which concerns on the Example of this invention. Explanatory drawing which shows an example of the state which measures a water level using the water level measurement system which concerns on the Example of this invention. Explanatory drawing which shows an example of the state which measures a water level using the water level measurement system which concerns on the Example of this invention. Explanatory drawing which shows an example of the state which measures a water level with the conventional method. Explanatory drawing which shows an example of the state which measures a water level with the conventional method. Explanatory drawing which shows an example of the state which measures a water level with the conventional method.

  Hereinafter, a liquid level measurement probe, a liquid level measurement system, and a liquid level measurement method according to the present invention will be described in detail based on examples.

[Example 1]
A water level measurement probe 10 according to a first embodiment of the present invention will be described with reference to FIG.
The water level measurement probe 10 is an integrated combination of an ultrasonic probe 11 and a gravity sensor 12. The ultrasonic probe 11 has a probe surface 11a that contacts an inspection object. The probe surface 11a is a surface that emits ultrasonic waves and receives reflected echoes. The gravity sensor 12 outputs a gravity detection signal (for example, a voltage signal) having a maximum value corresponding to gravity when the sensor shaft 12a is oriented in the vertical direction. Therefore, when the sensor shaft 12a is tilted with respect to the vertical direction, the value of the gravity detection signal decreases as the tilt increases.
In the water level measurement probe 10 of this example, the ultrasonic probe 11 and the gravity sensor 12 are combined in a state where the sensor axis 12a of the gravity sensor 12 is orthogonal to the probe surface 11a of the ultrasonic probe 11. Integrated. Therefore, when the probe surface 11a becomes horizontal, the sensor shaft 12a is oriented in the vertical direction, and the value of the gravity detection signal is maximized.

  The gravity sensor 12 incorporated in the water level measurement probe 10 shown in FIG. 1 outputs a gravity detection signal (for example, a voltage signal) having a minimum value corresponding to gravity when the sensor shaft 12a is oriented in the vertical direction. A type of sensor can also be used. When such a type of gravity sensor 12 is used, when the probe surface 11a becomes horizontal, the sensor shaft 12a is directed in the vertical direction, the value of the gravity detection signal is minimized, and the sensor shaft 12a is As the inclination increases with respect to the vertical direction, the value of the gravity detection signal increases as the inclination increases.

  In any case, as the gravity sensor 12 incorporated in the water level measurement probe 10 shown in FIG. 1, when the sensor shaft 12a is oriented in the vertical direction, the value of the gravity detection signal becomes an extreme value (maximum value or minimum value). Is adopted.

[Example 2]
Next, a water level measurement system 100 according to a second embodiment of the present invention and a method for measuring the water level using the water level measurement system 100 will be described with reference to FIG. The water level measurement system 100 includes a water level measurement probe 10 and a water level measurement device 110.

The water level measurement probe 10 is the same as that shown in FIG. 1 and is an integrated combination of an ultrasonic probe 11 and a gravity sensor 12.
The ultrasonic probe 11 generates an ultrasonic wave from the probe surface 11a, receives a reflected echo, and outputs a reflected echo signal a corresponding to the received reflected echo.
The gravity sensor 12 outputs a gravity detection signal b corresponding to the detected gravity. In the gravity sensor 12, the value of the gravity detection signal b becomes the maximum value (extreme value) when the sensor shaft 12a is oriented in the vertical direction, and the inclination increases as the sensor shaft 12a is tilted with respect to the vertical direction. A type in which the value of the gravity detection signal b becomes smaller is adopted.
Therefore, when the water level measurement probe 10 is arranged at the lowermost position among the outer peripheral surfaces of the horizontally arranged pipes, and the probe surface 11a of the ultrasonic probe 11 is in a horizontal state and comes into contact with the pipe outer peripheral surface. Further, the sensor shaft 12a of the gravity sensor 12 is oriented in the vertical direction, and the value of the gravity detection signal b is maximized.

  The water level measuring instrument 110 has a lowermost position detection unit 120, an ultrasonic measurement unit 130, and a notification unit 140. The lowermost position detection unit 120 includes a lowermost position determination unit 121 and a gravity value memory 122. The ultrasonic measurement unit 130 includes an ultrasonic search unit 131, a waveform signal memory 132, a waveform display unit 133, and an input unit 134. The notification unit 140 includes a notification drive unit 141, a lamp 142, and a buzzer 143.

  In order to detect the water level of the water W inside the horizontally disposed pipe P by the water level measurement system 100, first, the “lowermost position detection procedure” is performed, and then the “water level measurement procedure” is performed. Each procedure and the processing operation of each part of the water level measurement system 100 during the procedure will be described sequentially.

<Lower end position detection procedure>
In the first step of detecting the lowermost position, the inspector holds the water level measurement probe 10 in his / her hand and, as shown by the solid line in FIG. 3, the lowermost position α of the outer peripheral surface of the pipe P (the outer surface of the inspection surface). Further, the probe surface 11a of the ultrasonic probe 11 is brought into contact with the upper position β on one end side (left side in FIG. 3). The water level measurement probe 10 is scanned from the upper position β to the lowermost position α by scanning the water level measurement probe 10 along the circumferential direction while maintaining the state in which the probe surface 11a is in contact with the outer peripheral surface of the pipe P in this way. Further, scanning is performed from the lowest end position α toward the upper position γ on the other end side (right side in FIG. 3) (first scan).

In this way, the operation of the water level measurement system 100 when the water level measurement probe 10 is scanned (first scan) and moved from position β → position α → position γ will be described.
When the water level measurement probe 10 is scanned in the circumferential direction, the gravity detection signal b continuously output from the gravity sensor 12 is input to the lowest end position determination unit 121. The lowest end position determination unit 121 successively detects the gravity value c, which is the value of the gravity detection signal b that is continuously input, and stores each gravity value c in the gravity value memory 122. Further, the lowermost position determination unit 121 compares the gravity values c stored in the gravity value memory 122 and specifies the maximum value (extreme value) as the maximum gravity value (extreme gravity value) mc. Store in the value memory 122. That is, since the gravity value c is detected one after another and stored in the gravity value memory 122, even if the maximum gravity value mc is temporarily specified in the middle of the scanning, a larger value is set thereafter. When the gravity value c is detected and stored, this larger value is specified as the maximum gravity value mc, and the storage is updated.

  In the second step of detecting the lowest end position, the inspector holds the water level measurement probe 10 in his / her hand and maintains the state in which the probe surface 11a is in contact with the outer peripheral surface of the pipe P. The ultrasonic probe 11 is scanned again (second scan) along the circumferential direction from a position (for example, the upper position γ) above the lowermost position α toward the lowermost position α.

  As will be described later, when the water level measurement probe 10 is located at the lowermost position α, the lamp 142 of the notification unit 140 is turned on or the buzzer 143 is ringed. Then, the scanning of the water level measurement probe 10 is stopped. By doing in this way, the water level measurement probe 10 can be located in the lowest end position (alpha).

The operation of the water level measurement system 100 when the water level measurement probe 10 is re-scanned (second scan) and moved from the upper position toward the lowest end position α will be described.
When the water level measurement probe 10 is rescanned in the circumferential direction (second scan), the gravity detection signal b is continuously output from the gravity sensor 12 and input to the lowermost position determination unit 121. The lowest end position determination unit 121 detects the gravity value c, which is the value of the gravity detection signal b continuously input at the time of rescanning, one after another. The lowermost position determination unit 121 compares the gravity value c detected one after another at the time of re-scanning with the maximum gravity value (extreme gravity value) mc previously specified and stored, and detects the detected gravity value. When c coincides with the maximum gravity value (extreme gravity value) mc, the trigger signal d is output to the ultrasonic search unit 131 of the ultrasonic measurement unit 130.

  The trigger signal d is continuously output while the detected gravity value c coincides with the maximum gravity value mc. Thereafter, the water level measurement probe 10 is shifted from the lowermost position, and the detected gravity value is detected. When c is different from the maximum gravity value mc, the output of the trigger signal d is stopped.

<Water level measurement procedure>
Next, the water level measurement procedure and the operation of the water level measurement system 100 at that time will be described.
When the inspector holds the water level measurement probe 10 and keeps the probe surface 11a in contact with the outer peripheral surface of the pipe P while scanning the ultrasonic probe 11 in the circumferential direction. The ultrasonic probe 11 emits an ultrasonic wave, receives a reflected echo, and outputs a reflected echo signal a corresponding to the reflected echo. When the reflected echo signal a is input, the ultrasonic search unit 131 generates and outputs an ultrasonic waveform signal e indicating an ultrasonic waveform (for example, an A scope waveform) from the reflected echo signal a. The waveform display unit 133 receives the ultrasonic waveform signal e and displays an ultrasonic waveform (for example, an A scope waveform) based on the ultrasonic waveform signal e.

The ultrasonic search unit 131 further performs the following determination process.
(I) Whether the value (amplitude value) of the ultrasonic waveform signal e is larger than a preset gate signal (threshold value).
(Ii) Whether or not the trigger signal d is input from the lowest end position determination unit 121 to the ultrasonic search unit 131.

When the next state is satisfied, the ultrasound search unit 131 performs a screen freeze operation (details will be described later).
That is, (i) the value (amplitude value) of the ultrasonic waveform signal e is larger than a preset gate signal (threshold value), and (ii) the trigger signal d is sent from the lowermost position determination unit 121 to the ultrasonic search unit 131. In other words, when
(I) The probe surface 11a of the ultrasonic probe 11 is firmly in contact with the outer peripheral surface of the pipe P,
(II) The water level measurement probe 10 is located at the lowermost position of the outer peripheral surface of the pipe P.
When the two conditions are met, the screen freezes.

What is screen freeze operation?
Since the probe surface 11a of the ultrasonic probe 11 is firmly in contact with the outer peripheral surface of the pipe P, the value (amplitude value) of the ultrasonic waveform signal e is larger than a preset gate signal (threshold value). ,
Since the water level measurement probe 10 is located at the lowermost position on the outer peripheral surface of the pipe P, the trigger signal d is input from the lowermost position determination unit 121 to the ultrasonic search unit 131.
When the two conditions are met, the ultrasonic waveform signal e at that time is held, and the held ultrasonic waveform signal e is continuously output. Therefore, when the screen is frozen, the waveform display unit 133 continuously displays the ultrasonic waveform based on the stored ultrasonic waveform signal e.
When the screen is frozen, the display unit 131a of the ultrasonic search unit 131 displays that the screen is frozen.

  The notification drive unit 141 of the notification unit 140 is connected to the lowermost position determination unit 121. When the trigger signal d is input, the lamp 142 is turned on and the buzzer 143 is sounded. In other words, it performs a notification operation that can be recognized (recognized) by human vision and hearing. By such notification, the inspector can easily know that the water level measurement probe 10 is located at the lowest end position on the outer peripheral surface of the pipe P.

  The notification drive unit 141 once receives the trigger signal d, but when the trigger signal d is not received after that, the lamp 142 is turned off and the buzzer 143 stops ringing. By stopping the notification in this manner, the inspector can know that the water level measurement probe 10 has shifted from the lowermost position on the outer peripheral surface of the pipe P.

When the inspector views the ultrasonic waveform displayed in the freeze state on the waveform display unit 133 and determines that the ultrasonic waveform is not an abnormal waveform, the inspector acknowledges the ultrasonic search unit 131 from the input unit 134. Send signal f. When the acknowledgment signal f is input, the ultrasonic search unit 131 sends the stored ultrasonic waveform signal e to the waveform signal memory 132 for storage and storage.
The inspector detects the water level by looking at the ultrasonic waveform displayed in the freeze state on the waveform display unit 133 or analyzing the ultrasonic waveform signal e stored and stored in the waveform signal memory 132. Can do.

  On the other hand, when the inspector views the ultrasonic waveform displayed in the freeze state on the waveform display unit 133 and determines that the ultrasonic waveform is an abnormal waveform, the inspector searches the ultrasonic search unit 131 from the input unit 134. Sends a non-acknowledgment signal g. When the non-approval signal g is input, the ultrasonic search unit 131 discards the ultrasonic waveform signal e stored and held in the waveform signal memory 132 and deletes the display of the freeze image in the waveform display unit 133.

If the water level measurement system 100 shown in FIG. 2 is used, the following measurement operation can be performed.
-By performing the first scan, the maximum gravity value (extreme gravity value) mc, which is the gravity value c when the water level measurement probe 10 is located at the lowermost position, is obtained.
When the second scan is performed, the trigger signal d is output when the gravity value c reaches the maximum gravity value (extreme gravity value) mc, the lamp 142 of the notification unit 140 is turned on, and the buzzer 143 is Annunciation is performed to sound. For this reason, the water level measurement probe 10 can be positioned at the lowest end position α of the pipe P by stopping the second scanning when the notification operation is performed.
The trigger signal d is output when the water level measurement probe 10 is positioned at the lowermost position α of the pipe P, and the probe surface 11a of the ultrasonic probe 11 is firmly in contact with the outer peripheral surface of the pipe P and is super When the value (amplitude value) of the sound waveform signal e becomes larger than a preset gate signal (threshold value), the ultrasonic waveform signal e at this time is held, and the ultrasonic waveform by the ultrasonic waveform signal e is changed. Displayed continuously (freeze image display).

  For this reason, as shown in FIG. 4, the inspector can easily know that the water level measurement probe 10 is located at the lowest end position of the pipe P, and the water level in the pipe P can be accurately seen by looking at the freeze image. Can be measured.

As shown in FIGS. 5 and 6, when the water level measurement probe 10 is shifted from the lowermost position of the pipe P, the trigger signal d is not output, so the notification operation is not performed and the freeze image is displayed. Is never displayed. For this reason, the water level is not erroneously measured.
Further, as shown in FIG. 4, even when the water level measurement probe 10 is located at the lowermost position of the pipe P, if the probe surface 11a is not in close contact with the outer peripheral surface of the pipe P, an ultrasonic waveform signal is obtained. Since the amplitude of e does not exceed the gate signal, no freeze image is displayed. For this reason, the water level is not erroneously measured.

  In the water level measurement system 100 of FIG. 2, (i) the value (amplitude value) of the ultrasonic waveform signal e is larger than a preset gate signal (threshold value), and (ii) the ultrasonic wave is detected from the lowest end position determination unit 121. When the trigger signal d is input to the search unit 131, the ultrasonic search unit 131 enters the screen freeze operation. Of the conditions (i) and (ii), one of the conditions (ii) The screen freeze operation can be started only when the above is established.

  Further, in addition to the above conditions (i) and (ii), when the acknowledgment signal f is input to the ultrasonic search unit 131, the ultrasonic search unit 131 may enter the screen freeze state.

  In addition, if water is sprayed on the outer peripheral surface of the horizontally arranged pipes P before measuring the water level, the water flows downward along the outer peripheral surface of the pipe due to gravity and accumulates as water droplets at the lowest end position of the outer peripheral surface of the pipe. . If this accumulated water is used as a contact medium, the water level can be measured easily and accurately.

If the water level measurement system shown in FIG. 2 is used, even in a structure such as a tank whose bottom surface is gradually curved downward in the vertical direction, the water level in the tank can be easily adjusted from the outer surface of the bottom surface. And it can measure accurately.
Of course, the liquid level of various liquids can be detected, not limited to water.

As the gravity sensor 12 incorporated in the water level measurement probe 10, a sensor of a type that outputs a gravity detection signal (for example, a voltage signal) having a minimum value corresponding to gravity when the sensor shaft 12a is oriented in the vertical direction is used. You can also.
When such a type of gravity sensor 12 is used, the lowest end position determination unit 121 continuously outputs from the gravity sensor 12 when scanning the water level measurement probe 10 (first scan). Among the values of the gravity detection signal b, the minimum value (extreme value) is specified as the minimum gravity value (extreme gravity value) mc and stored in the gravity value memory 122.
Furthermore, when the water level measurement probe 10 is re-scanned (second scan), the lowermost position determination unit 121 determines a gravity value c that is a value of the gravity detection signal b continuously input from the gravity sensor 12. The gravity value c detected one after another is compared with the minimum gravity value (extreme gravity value) mc previously specified and stored, and the detected gravity value c is the minimum gravity value (extreme gravity value). ) When the value coincides with mc, the trigger signal d is output to the ultrasonic search unit 131 of the ultrasonic measurement unit 130 and the notification drive unit 141 of the notification unit 140.
The configuration and operation of other parts are the same as those described above.

  The present invention relates to a liquid (for example, water) existing inside a structure that contains a liquid such as a horizontally arranged pipe or a tank whose bottom surface is gradually curved downward in the vertical direction. It can be used when detecting the liquid level (water level).

DESCRIPTION OF SYMBOLS 10 Water level measurement probe 1,11 Ultrasonic probe 11a Probe surface 12 Gravity sensor 100 Water level measurement system 110 Water level measuring device 120 Bottom end position detection part 121 Bottom end position judgment part 122 Gravity value memory 130 Ultrasonic measurement part 131 Ultrasonic search unit 131a Display unit 132 Waveform signal memory 133 Waveform display unit 134 Input unit 140 Notification unit 141 Notification drive unit 142 Lamp 143 Buzzer a Reflected echo signal b Gravity detection signal c Gravity value d Trigger signal e Ultrasonic waveform signal f Acknowledgment signal g Unacknowledged signal

Claims (6)

  An ultrasonic probe that has a probe surface that emits ultrasonic waves and receives reflected echoes, and a gravity sensor that outputs a gravity detection signal with a value corresponding to gravity when the sensor axis is oriented in the vertical direction. The liquid level measurement probe, wherein the ultrasonic probe and the gravity sensor are integrated in a state where the sensor axis is orthogonal to the probe surface. The liquid level measuring probe according to claim 1 and a liquid level measuring instrument,
The liquid level measuring instrument is
The gravity detection signal is input from the gravity sensor, an extreme value among the detected gravity values is specified and stored as an extreme gravity value, and a trigger signal is output from the lowest end position detection unit and the ultrasonic probe. When a reflected echo signal corresponding to the reflected echo is input from the touch element, an ultrasonic waveform signal indicating an ultrasonic waveform is formed, and the ultrasonic waveform is displayed by the ultrasonic waveform signal. An ultrasonic measurement unit that holds the ultrasonic waveform signal when the trigger signal is input and continuously displays the held ultrasonic waveform;
A notification unit that performs a notification operation when the trigger signal is input;
A liquid level measurement system comprising: In claim 2,
The ultrasonic measurement unit continuously displays the ultrasonic waveform when the trigger signal is input and the amplitude value of the ultrasonic waveform signal is larger than a predetermined threshold value. system. In claim 2 or claim 3,
The ultrasonic measurement unit has an input unit, and stores the held ultrasonic waveform signal when an approval signal is input from the input unit. In claim 4,
The ultrasonic measurement unit holds and holds the ultrasonic waveform signal when the trigger signal is input and the amplitude value of the ultrasonic waveform signal is larger than a predetermined threshold and the approval signal is further input. A liquid level measurement system that continuously displays an ultrasonic waveform using an ultrasonic waveform signal. A liquid level measuring probe according to claim 1 is used to scan a convex inspection surface that is gradually curved downward in the vertical direction among the surfaces of the structure in which the liquid is stored. Is a method of measuring
With the probe surface in contact with the outer surface of the inspection surface, the liquid level measurement probe passes through the lowermost position from a position higher than the lowermost position of the inspection surface and further passes the lowermost position. Scanning to a position, and specifying and storing an extreme value among the values of the gravity detection signal obtained at the time of scanning as an extreme gravity value,
In a state where the liquid level measurement probe is placed at a position where the value of the gravity detection signal becomes the extreme gravity value, an ultrasonic waveform signal is obtained from a reflected echo signal obtained from the ultrasonic probe, A liquid level measurement method, wherein the liquid level of the liquid is measured based on a sound wave waveform signal.

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