KR101663815B1 - Device for measuring and calibrating ultrasonic level automatically - Google Patents

Abstract

An embodiment of the present invention relates to an apparatus to automatically measure an ultrasonic wave level. A technical task is to automatically measure an ultrasonic wave level of an electrical board in various environment changes. According to an embodiment of the present invention, the apparatus to automatically measure a ultrasonic wave level comprises: a signal reception unit to receive electric signals corresponding to components installed inside an electrical board to detect an ultrasonic wave and a noise generated around the components; a signal amplification unit to amplify the received electric signals with a predetermined ratio; a relay unit installed between the signal reception unit and the signal amplification unit and to receive or block the ultrasonic wave electric signal from the signal reception unit; and a controller to input a control signal to receive the electric signals to the relay unit, to set a zero point by using electric signals received in the relay unit, to correct the zero point by applying a preset prediction program to the analyzed electric signal after analyzing the detected noise electric signal in a state to block the ultrasonic electric signal through the relay unit when the noise having fluctuation over preset fluctuation among the electric signals is detected, and to receive the ultrasonic electric signal through the relay unit based on the corrected zero point.

Description

TECHNICAL FIELD [0001] The present invention relates to an ultrasonic level automatic measurement apparatus,

An embodiment of the present invention relates to an apparatus for automatically measuring an ultrasonic level.

The switchgear is a device that feeds the high-voltage power supplied from the substation down to commercial voltage and supplies it to the customer.

Specifically, the switchboard includes a power reception facility for receiving high-voltage power supplied from a substation, a substation for lowering the high-voltage power received from the substation to a commercial voltage, a substation for supplying the substation with electric power, Power distribution equipment, switchgear, and other safety devices.

In an enclosed switchboard applied to such a switchboard, deterioration or mechanical damage may occur depending on the service life, the installation environment, and the operating conditions of the insulator used for the connecting portion and the supporting portion. As the insulator is damaged, the degree of damage is deepened due to the high voltage discharge phenomenon in a short period of time, and when it is left to stand, an arc is generated, which may lead to insulation breakdown and fire. Accordingly, there is a need for a device that is economically and reliable as a device suitable for safely detecting insulation failure in a state in which a power plant is normally operated (live state) in order to prevent such a disaster by detecting such a situation in advance.

Generally, it is common practice to use a laboratory equipment that detects temperature, radio waves, ultrasound, and ultraviolet rays to perform inspection by a qualified inspector in accordance with a predetermined periodicity.

In particular, in the method of measuring the ultrasonic level in the switchboard, the noise level is measured in a silent state at the place where the measuring apparatus is installed, and the value is added to the maximum value of the variation range of the noise level for a predetermined time, Value), and the measurement is performed in such a manner that the input is displayed above the value.

However, at this time, the sensor receiving the ultrasound varies in characteristics depending on the temperature and the humidity, and all components used as the amplifier and the filter are changed according to the temperature and the humidity.

Therefore, it is necessary to make a measurement before the test to find the level of the zero value of the non-signal. In addition, if the temperature and humidity, which is one of the test conditions, change due to various reasons while measuring well, the zero value is changed and the signal is not detected It is possible to generate an error that displays a certain value even in a silent mode. In addition, the noise coming from various surrounding sources can be seen as a malfunction due to the large amplification factor of the amplifier.

Furthermore, since this method always measures the noise level and the noise level change in the silent state at the start of the measurement, it is cumbersome and requires a lot of measurement time, and there is also a problem that individual variation is caused by the expertise of the measurer.

Patent Registration No. 10-1457881 (Date of Publication: Apr. 2014, Patent Registration No. 10-1176049 (Publication Date: Aug. 24, 2012)

An embodiment of the present invention provides an ultrasonic level automatic measurement apparatus capable of automatically measuring an ultrasonic level of accessories of a server in various environments.

The apparatus for automatically measuring an ultrasonic level according to an embodiment of the present invention receives electric signals from accessories installed inside the switchboard so as to detect ultrasonic waves and noise generated by the accessories installed in the switchboard or around the accessories A signal receiving unit; A signal amplifying unit for amplifying the received electrical signals at a preset ratio; A relay unit installed between the signal receiving unit and the signal amplifying unit and receiving or blocking an ultrasonic electric signal from the signal receiving unit; And a control unit for inputting a control signal for receiving the electric signals to the relay unit and setting a zero point by using the electric signals received by the relay unit, Wherein the analyzer analyzes the detected noise electrical signal in a state in which the ultrasonic electric signal is blocked through the relay unit when noise is detected and then applies the analyzed electric signal to a predetermined prediction program to correct the zero point, And a controller for controlling the ultrasonic electric signal to be received through the relay unit based on the corrected zero point.

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The controller may predict a maximum value of the fluctuation width of the detected noise through the preset prediction program and then correct the zero value using the predicted maximum value.

Further, the present invention may further comprise a self-diagnosis unit for determining whether the ultrasonic level automatic measurement apparatus is normally operated, the self-diagnosis unit comprising: a self test signal generator for supplying a preset diagnostic signal; A signal attenuator for attenuating the diagnostic signal to a predetermined reference level; A signal transfer unit for switching the supply of the attenuated diagnostic signal; And an operation determiner for comparing the predetermined pattern signal with a diagnostic signal transmitted through the signal transfer unit to determine whether the ultrasonic level automatic measurement apparatus is normally operated.

The self-diagnosis unit may further include an alarm signal output unit for outputting an alarm signal to the outside when it is determined that the ultrasonic level automatic measurement apparatus is not operated normally.

The signal transfer unit may include any one of a pin diode, a relay circuit, and a transistor.

The automatic ultrasonic level measuring apparatus according to an exemplary embodiment of the present invention automatically enters a silent mode using a relay to set a zero value, predicts a maximum value of a variation range of a noise level through a predetermined prediction program, , The ultrasonic level of the accessories of the switchgear can be automatically measured even under various environmental changes.

In addition, an embodiment of the present invention can shorten a test preparation period for ultrasonic level measurement to a minimum time.

1 is a schematic view of an apparatus for automatically measuring an ultrasonic level according to an embodiment of the present invention.
FIG. 2 is a circuit diagram of the automatic ultrasonic level measuring apparatus of FIG. 1; FIG.
FIG. 3 is a view schematically showing the self diagnosis unit of FIG. 1. FIG.
4 is a diagram showing an example of the relay unit of FIG.
5A and 5B are flowcharts illustrating an operation of an automatic ultrasonic level measuring apparatus according to an embodiment of the present invention.
6 is a diagram illustrating a self-diagnosis algorithm of an automatic ultrasonic level measuring apparatus according to an embodiment of the present invention.

The terms used in this specification will be briefly described and the present invention will be described in detail.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. Also, in certain cases, there may be a term selected arbitrarily by the applicant, in which case the meaning thereof will be described in detail in the description of the corresponding invention. Therefore, the term used in the present invention should be defined based on the meaning of the term, not on the name of a simple term, but on the entire contents of the present invention.

When an element is referred to as "including" an element throughout the specification, it is to be understood that the element may include other elements as well, without departing from the spirit or scope of the present invention. Also, the terms "part," " module, "and the like described in the specification mean units for processing at least one function or operation, which may be implemented in hardware or software or a combination of hardware and software .

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Generally, the apparatus for measuring the ultrasonic level of the components installed in the switchboard measures the noise level of the RF final stage in the silent state of the place where the device is installed by using a spectrum analyzer, The shape is primarily determined by the gain of the internal filter and the amplifier and is secondarily varied by temperature, humidity, or ambient noise conditions, but the width of the boundary becomes thicker or thinner while maintaining the shape of the primary determined waveform It changes up and down.

Therefore, the existing ultrasonic level measuring apparatus adds ultrasonic wave sensed value and maximum value of variation range of noise level for a predetermined time, sets it as ZERO value, and displays ultrasonic wave measurement by displaying the input above the value. However, this method should always measure the noise level and the noise level change at the start of measurement.

Accordingly, the present invention provides a relay at an input terminal of the apparatus, thereby automatically entering a silent mode through a silent mode, making a silent state, measuring a noise to set a zero value, The maximum value of the noise level variation width is predicted and applied, and the relay is automatically switched to the measurement mode for measurement. Accordingly, the present invention can shorten the test preparation time to the minimum time and set the calibration time so that automatic measurement can be performed even in various environment changes.

FIG. 1 is a schematic view of an apparatus for automatically measuring an ultrasonic level according to an embodiment of the present invention, FIG. 2 is a circuit diagram for implementing the ultrasonic level automatic measuring apparatus of FIG. 1, and FIG. 3 is a schematic Fig. 4 is a diagram showing an example of the relay unit of Fig. 1. Fig.

1 and 2, an ultrasonic level automatic measuring apparatus 10 according to an exemplary embodiment of the present invention can detect an ultrasonic level of an ultrasonic wave when an ultrasonic wave is generated from various accessories including wirings, terminals, switches, A signal amplifying unit 130, a relay unit 120, a controller 140, and a self-diagnosis unit (not shown). The signal receiving unit 110 amplifies a weak signal included in the signal, 150).

The signal receiving unit 110 receives the electric signals from the accessories 1 installed in the switchboard so as to detect ultrasonic waves and noise generated by the accessories installed in the switchboard or around the accessories. For this purpose, the signal receiving unit 110 is wirelessly connected to each of the accessories 1. [ At this time, the accessories 1 may be provided with an ultrasonic sensor, a temperature sensor, a humidity sensor, and a noise sensor.

The signal amplifying unit 130 amplifies the electric signals received by the signal receiving unit 110 at a preset ratio. The signal amplification unit 130 outputs the amplified electrical signals in a predetermined waveform form and inputs the amplified electrical signals to a spectrum analyzer.

The relay unit 120 is installed between the signal receiving unit 110 and the signal amplifying unit 130 and receives or blocks an ultrasonic electric signal from the signal receiving unit 110. The relay unit 120 may include any one of a pin diode, a relay circuit, and a transistor. In addition, the relay unit 120 may use an RF switch applied to an RF circuit.

The controller 140 inputs a control signal for receiving electrical signals to the relay unit 120 and performs a zero (0) point setting using the electrical signals received by the relay unit 120. The controller 140 analyzes the detected noise electric signal in a state where the ultrasonic electric signal is blocked through the relay unit 120 when noise having a predetermined variation width or more is detected among the electric signals, The analyzed electric signal is applied to a preset prediction program to correct the zero point and controls to receive the ultrasonic electric signal through the relay unit 120 based on the corrected zero point.

That is, when the noise having a predetermined variation width or more is detected, the controller 140 enters the silent mode and blocks the ultrasonic electrical signal through the relay unit 120. When the zero point is corrected, And controls to receive the ultrasonic electric signal through the relay unit 120 based on the corrected zero point.

In addition, the controller 140 may predict a maximum value of the fluctuation range of the detected noise through a preset prediction program, and then correct the zero value using the predicted maximum value.

When the temperature is detected, the controller 140 reads the table of the corresponding margin from a previously stored database and calculates a margin based on the detected temperature. And optimizes the level of the signal to be inspected.

In addition, since the controller 140 is continuously generated during the measurement of ultrasonic signals, instantaneous shock waves are input through various paths due to external conditions in actual operation, and adaptive filtering ADATIVE FILTERING.

On the other hand, in a region where a minimum signal to be input is normally detected, an input signal is frequently disconnected, and a special algorithm for analyzing the input signal is required. Typically, a method of measuring the average value several times is used. The controller 140 of the present invention grasps the difference between the maximum value and the minimum value more finely for finer distinction that can not be detected by the conventional method because there is a slight noise level change even in a region where there is no signal, By distinguishing the presence or absence of the signal by the amount of change of the magnitude of the maximum value and the minimum value in a certain period by using an algorithm for distinguishing between the magnitude of the signal and the measured value of the portion where the signal is sensed.

On the other hand, since the ultrasonic level automatic measuring apparatus 10 can completely recognize the characteristics of the noise floor in order to completely block the ultrasonic signal, the ultrasound signal is blocked through the relay unit 120, 2), and by impedance matching the connection pattern, it is possible to obtain a noise floor in which the input ultrasonic signal is completely removed. However, when the frequency characteristics of the noise floor through a pre-adjusted RF filter are measured by a spectrum analyzer, the values vary depending on the surrounding conditions (for example, temperature, humidity change, etc.) ) Can have a changing characteristic. In view of this point, in the present invention, a pre-test for setting a reference value is automatically measured, and the noise floor is automatically measured after the temperature changes or a predetermined time elapses So that the ultrasonic diagnosis can be performed more reliably by making the measurement by reflecting the change.

This operation will be described in more detail with reference to the circuit diagram of FIG. 2. In the case where a signal of RF_IN, which is a weak signal inputted to the detection sensor receiving the ultrasonic wave by the pin 4, is inputted, RELAY RL1 is connected to the normally- (NORMAL CLOSE) pin to CAPACITOR C01. At this time, the applied signal can be outputted as a spectral output of the AMP terminal through the amplification and the filter, and the signal is converted into a DC voltage corresponding to the signal size by the detection circuit (not shown) That is, the controller 140), and displays the presence / absence and the magnitude of the signal.

In this process, when the SET_1 command is received from the controller 140 (CPU_xxx) in order to find the value when there is no signal, 5V voltage is applied to the first pin of the RELAY RL1 through the resistors R09 and TRANSISTER Q04 so that the relay RL1 operates , So that pin 4 and pin 6 are in the OPEN state and pin 4 is connected to pin 8. Then the RF_IN signal input by the TRM1 50 Ohm termination resistor connected to pin 4 is all destroyed and no signal is applied through C01.

At this time, the output terminal of the amplifier is measured by the spectrum. At this time, the detected signal is converted into DC voltage corresponding to the signal size by the detection circuit, inputted to the ADC IC, and indicated as "0" .

As shown in FIG. 2 for implementing the above-described operation, the functions of the respective elements provided in the ultrasonic level automatic measuring apparatus 10 are as follows.

First, RESISTOR R9 attenuates the signal from the CPU and adjusts the current level to the proper operating range of the Q04 TRANSISTOR to prevent overload.

In addition, CAPACITOR C35 is used for bypass to stabilize noise and supply power.

In addition, FERRITE BEAD FB6 acts as EMI / EMC (shielding / shielding), CAPACITOR C36 acts as a noise eliminator, and INDUCTOR L09 acts as a shield for high frequency.

In addition, RESISTOR R8 can attenuate the voltage from the power supply and adjust the corresponding voltage and current to the appropriate operating range in the Q04 TRANSISTOR to obtain the proper gain (GAIN) and protect the Q04 TRANSISTOR.

Also, CAPACITOR C37 acts as a noise eliminator, DIODE D03 acts to prevent counter electromotive force generated in a coil that operates a relay, and RF_IN terminal acts as a terminal pin connected to a sensor that receives an ultrasonic signal.

If there is no ON signal from the RF_IN CPU_XXX, the relay element RELAY RL1 causes the applied ultrasonic signal to flow to the CAPACITOR C01 because the PIN 4 contact and the PIN 6 contact are connected and when the ON signal is detected from the RF_IN CPU_XXX The ultrasonic signal is connected to PIN 4 and PIN 8, and PIN 6 is dropped so that the signal is connected to TERMINATOR TRM 1.

In addition, the CAPACITOR CXX acts as a noise eliminator and the TERMINATOR TRM1 serves to attenuate the RF_IN signal sufficiently to prevent impedance matching and RF_IN signals from being reflected or propagated around.

Meanwhile, as shown in FIG. 4, the relay provided in FIG. 2 includes a core, a bobbin, a coil, a steel contact, a contact, a case, and the like.

 The operating principle of the relay thus constructed is based on the principle of an electromagnet which generates magnetic force when a current is passed through a coil wound around the bobbin.

Accordingly, when the relay contacts the iron contact and the contact, the magnetic core generates magnetic force when the electric current is passed. When the contact is made at the distance where the iron piece moves, the iron contact and the contact are attached. In contrast to this, when there is no current in the coil, it attaches the contact point of the iron wire and the contact point, and when the current is supplied to the core, a magnetic force is generated in the core, so that the iron wire contact point is pulled out so that the iron wire contact point and the contact point are separated. And multiple pairs of contacts can be designed to operate by one core and a coil.

More specifically, if there is no signal at the coil end of the relay, the voltage between the first pin and the eighth pin is 0V. In this state, the contact of the relay keeps the states of 4th and 6th pins, 13th and 11th pins always attached, and keeps the states of 4th and 8th pins, 13th and 9th pins apart.

That is, if there is a signal at the coil end of the relay, the voltage between pin 1 and pin 8 is 5V. In this state, the current flowing through the coil drives the electromagnet, and the contact of the relay by the force of the magnet is a state in which the pin 4 and pin 8, pin 13 and pin 9 are always stuck and pin 4, pin 6, pin 13 The pin 11 is kept apart.

The self-diagnosis unit 150 is a device for determining whether the ultrasonic level automatic measuring apparatus 10 is normally operated, and self-diagnoses whether the automatically operated ultrasonic measuring apparatus operates normally.

3, the self-diagnosis unit 150 includes a self-test signal generator 151, a signal attenuator 152, a signal switch 153, an operation determiner 154, (Not shown).

The self test signal generator 151 is a device for supplying a predetermined diagnostic signal and can be configured in four types.

That is, the DA CONVERT PIN of the CPU can be used first. Generally, there is a port that can make a digital-to-analog signal depending on the kind of MCU. In this case, when the data is sent to the corresponding port (for example, in the case of a CPU using a 5 V voltage, a voltage of 0 V is outputted when "00000000" is sent out of 8-bit data, 5 V and "10000000" 2.5 V is generated by using this principle. If the data is incremented by 1 at a predetermined time interval, then the data is continuously increased to the maximum value, and the data is repeatedly decreased by 1 to the minimum value, a sine signal is generated. A signal can be supplied as a diagnostic signal.

Second, you can make and supply sine waves with the DA Converter IC.

When a dedicated IC for DA Converter (for example, BH2226H from ROHM) is used, it can be implemented in products that do not have a DA converter function in the CPU. At this time, the operation principle is the same as the first case and the performance is relatively good.

Third, a clock pulse (square wave) can be supplied as a sine wave.

In general, many clock frequencies exist in a single product, and all CPUs have a counter function, so that it is easy to export a square wave of a desired frequency. However, since the ultrasonic signal is received in the form of a sine wave, a circuit that converts the square wave into a sine wave is needed.

Fourth, a sinusoidal generator IC (Sine generator ic) can be used.

If a precise sine wave is needed, a dedicated IC (for example ML2036) can be used to easily obtain the desired signal.

On the other hand, the internal sine signal obtained as described above is much larger than the ultrasound signal actually input and must be attenuated. To this end, the present invention includes a signal attenuator.

The signal attenuator 152 attenuates the diagnostic signal to a preset reference level, and a PI type, a T type, and a Bridge type may be used depending on the connection method of the resistor.

At this time, since the generated signal is a TTL level, it is a signal which is larger than the test signal by several tens of dB, and this level is lowered to a normal minimum reception sensitivity level or a desired level, and the attenuator is used to make the signal small to make various levels. These attenuators are constructed by connecting several resistors in series and in parallel.

The signal transfer unit 153 is an apparatus for performing switching on the supply of the diagnostic signal attenuated by the signal attenuation unit and may be formed using any one of a pin diode, a relay, and a transistor

First, the pin diode is a type of electronic component that performs basic operation and configuration of a control circuit that performs signal flow, phase change and phase control, such as a switch, a phase shifter, and an attenuator. By using the characteristics of a typical pin diode, Applying a voltage to it will work like a short, and without applying a voltage it will act like opening. This principle can be used to decide whether to connect the receiving sensor to the ultrasonic input or the internal signal in the form of a switch.

In addition, the transistor can be used as a switch at an ultrasound input terminal by using a switching characteristic of the device itself.

The operation determining unit 154 compares a predetermined pattern signal with a diagnostic signal that has passed through the signal transfer unit and determines whether the ultrasonic level automatic measuring apparatus 10 is normally operated. To this end, the operation determination unit may perform four processes of pattern storage data, pattern generation, comparison, and determination in order. That is, the operation determination unit can generate ultrasonic signals of various pattern shapes required for self diagnosis after a predetermined time (for example, one week) during operation of the apparatus, and send and analyze ultrasonic signals to accurately detect defects in the hardware.

Although there are obvious fault conditions in the symptoms of such hardware, when the symptom is varied and the symptom continues to deteriorate with time, when the symptom which is difficult to find easily changes due to voltage shock or aging, Some of the characteristics can be changed with Oosop. Many of these can not be distinguished from simple continuous signal tests.

Accordingly, in the present invention, the operation determination unit 154 generates a pattern signal that is stored in advance to distinguish the pattern signal, and receives the pattern signal to determine the correctness of the normal operation. To this end, the operation determination unit stores various patterns required for the inspection in the database, and when the cause of the failure is identified, the operation determination unit updates the database by patterning it, thereby contributing to the improvement of reliability.

The alarm signal output unit 155 is an apparatus that outputs an alarm signal to the outside when it is determined that the ultrasonic level automatic measurement apparatus 10 is not operated normally.

5A to 5B, the automatic ultrasonic level measuring apparatus 10 according to the embodiment of the present invention includes a step of initializing the equipment S1, a step S2 of preparing an ultrasonic input signal to be inputted into the switchboard, (S4) of transmitting and receiving a control signal from the controller (140), and setting a zero point by using the ultrasonic input signal and the control signal (S5) do.

Then, the automatic ultrasonic level measuring apparatus 10 according to an embodiment of the present invention includes a step S6 of storing measured silence basis data in a state in which a zero point is set, and a step S6 in which, (S7) of judging whether or not the temperature interval data is sensed, a step (S8) of detecting a temperature / humidity change, and a temperature comparing step (S81). In this case, steps S8 and S81 may include steps S9 and S82 for storing modified silent data, respectively.

However, the ultrasonic level automatic measuring apparatus 10 includes a step S51 of storing ultrasonic fundamental data measured in a state in which no zero point is set, a step S52 of calculating a difference between the basic data and the previously- (S53) of judging whether a sudden change of data occurs at this time, a step S54 of judging whether a weak signal occurs or not, a step of generating an alarm signal S55, Data or alarm signal data) on the screen (S56), and determining whether to turn off the driving of the apparatus (S57). At this time, S53 and S54 pass through the adaptive filtering process (S531 and S532) and the weak signal classification algorithm (S541 and S542), respectively.

6, a self-diagnosis algorithm for the ultrasonic level automatic measuring apparatus 10 according to an embodiment of the present invention will be described. First, a diagnosis flag is set, The self-diagnosis mode is switched to shut off the signal coming from the ultrasonic reception sensor, and the self-diagnosis signal is transferred through the attenuator.

Then, in order to generate a signal of the pattern, the patterns in the pattern database are inspected in order.

These patterns are signal patterns for identifying defects or states of certain components occurring in many cases. For example, if the pattern signal of "1110" is recorded in one pattern of DATABASE, the ultrasonic signal is generated in the INTERVAL of 1 and the ultrasonic signal is not generated in the INTERVAL of 0, If the results are shown, the values of the CAPs in the amplification section are inserted too large. It is possible to select such a defective part or a part that caused aging of the part.

As described above, the present invention is not limited to the above-described embodiments, but rather may be applied to other embodiments of the present invention, It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

1: Accessory 10: Ultrasonic level automatic measuring device
110: Signal receiving unit 120: Relay unit
130: signal amplifier 140: controller
150 self diagnosis unit 151 self test signal generation unit
152: Signal attenuator 153: Signal switcher
154: Operation determination unit 155: Alarm signal output unit

Claims (6)

A signal receiving unit for receiving the electric signals from accessories installed in the switchboard so as to detect ultrasonic waves and noise generated by the accessories installed in the switchboard or around the accessories;
A signal amplifying unit for amplifying the received electrical signals at a preset ratio;
A relay unit installed between the signal receiving unit and the signal amplifying unit and receiving or blocking an ultrasonic electric signal from the signal receiving unit; And
The relay unit receives a control signal for receiving the electric signals and performs a zero (0) point setting using the electric signals received in the relay unit. And a controller for analyzing the detected noise electrical signal in a state in which the ultrasonic electric signal is blocked through the relay unit when noise is detected and then applying the analyzed electric signal to a predetermined prediction program to correct the zero point, And a controller for controlling the ultrasonic electric signal to be received through the relay unit based on a zero point of the ultrasonic wave.
delete The method according to claim 1,
The controller
And predicts a maximum value of the fluctuation width of the detected noise through the preset prediction program, and then corrects the zero value using the predicted maximum value.
The method according to claim 1,
Further comprising a self-diagnosis unit for determining whether the ultrasonic level automatic measuring apparatus is normally operated,
The self-
A self test signal generator for supplying a preset diagnostic signal;
A signal attenuator for attenuating the diagnostic signal to a predetermined reference level;
A signal transfer unit for switching the supply of the attenuated diagnostic signal; And
And an operation determiner for comparing the predetermined pattern signal with a diagnostic signal transmitted through the signal transfer unit to determine whether the ultrasonic level automatic measurement apparatus is normally operated.
The method of claim 4,
The self-
And an alarm signal output unit for outputting an alarm signal to the outside when it is determined that the ultrasonic level automatic measuring apparatus is not operated normally.
The method of claim 5,
The signal transfer unit
A pin diode, a relay circuit, and a transistor.

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