KR102230260B1 - Data acquisition system including extensometer and method for structural integrity test using the same - Google Patents

Abstract

The present invention discloses a method for measuring displacement. More specifically, the present invention relates to a data collection system including an extensometer for performing a verification test on the structural integrity of a containment building of a nuclear power plant using an extensometer, and a structural integrity verification test method using the same. .
According to an embodiment of the present invention, it is connected to a sensor group including an extensometer to collect the measured variation of the displacement element, and based on the optimal algorithm, the structural integrity of the nuclear power plant containment building according to the displacement element variation value. It has the effect of providing an index that accurately reflects the verification test results.

Description

A data acquisition system including an extensometer and a structural integrity test method using the same {DATA ACQUISITION SYSTEM INCLUDING EXTENSOMETER AND METHOD FOR STRUCTURAL INTEGRITY TEST USING THE SAME}

The present invention relates to a displacement measurement method, in particular, a data collection system including an extensometer that performs a verification test on the structural integrity of a containment building of a nuclear power plant using an extensometer, and a structural integrity verification test method using the same It is about.

In general, the dome structure of a nuclear power plant is inevitably higher in importance and safety requirements than other general power generation facilities as core facilities such as nuclear reactors are concentrated.

Accordingly, it can be said that the dome structure of a nuclear power plant requires careful attention in all operational stages from the design stage to the operation stage, and it can be said that the safety review and confirmation are required at all times during the operation stage.

1 is an illustration of one of the safety structures applied to the containment building 10 such as a dome structure in a conventional nuclear power plant. As shown in FIG. 1, the containment building 10 is a concrete structure on the foundation. An outer wall 20 having an upper portion of a hemispherical dome is provided, and a separate space is formed therein, so that equipment such as a steam generator may be disposed.

And, under the outer wall 20, the base 30, which supports the equipment inside and is installed on the ground, is located, and the containment building 10 is isolated from the ground where vibration is generated in preparation for an earthquake. A separate seismic isolating device 40 is installed between the base 30 and the base 30 for the period. Here, the seismic isolator 40 performs a function of absorbing energy with deformability and energy dissipation ability horizontally while securing support safety vertically with respect to the outer wall 20.

The dome structure of the nuclear power plant described above requires careful attention from the design stage, and it is required to review and confirm its safety at all times even during operation, and continuous monitoring is required as even minute displacement fluctuations can cause major disasters.

Accordingly, the nuclear power plant operator must periodically perform a STRUCTURAL INTEGRITY TEST (SIT) for deformation of the external wall 20 as described above due to an increase in internal pressure. As such a integrity test, a displacement test using a displacement measuring device is performed. have.

As a widely used device for such a soundness test, there is a displacement extensometer. Extensometer refers to a device that measures and measures the distance or position that an object has moved. The measurement range is usually zero (0) to several millimeters (mm), or several centimeters (cm). As a sensor used, a magnetic sensor using a magnetic principle is representative.

In testing the structural integrity of the current nuclear power plant containment building, it is a method of simply measuring the displacement fluctuation through the extensometer by applying a predetermined pressure for the test to the measurement object and determining whether the standard value is satisfied. This has a limitation in deriving the verification test results for the actual structural integrity.

Registered Patent Publication No. 10-1090687 (announcement date: 2011.12.08.)

The present invention was conceived to solve the above-described problem, and the present invention obtains a measurement result for each pressure using a plurality of sensors including an extensometer, and applies an optimal algorithm to the predicted displacement and allowable displacement. There is a challenge in implementing a system that provides results of verification tests that accurately reflect the structural integrity of a nuclear reactor power plant.

In order to solve the above problems, a data collection system according to a preferred embodiment of the present invention includes a sensor group including an extensometer installed in a containment building of a nuclear power plant to measure fluctuations for one or more displacement elements, and the sensor. It may include a central control server that collects the variation of the measured displacement element connected to the military, and provides a result of a structural integrity verification test for the nuclear power plant containment building based on the variation value of the displacement element.

The extensometer is a 60-channel device for measuring linear displacement with respect to the nuclear power plant containment building, a first bracket installed at a reference point of the nuclear power plant containment building to provide a supporting force, and a first bracket fixed to the nuclear power plant containment building. 2 Bracket, a displacement meter body that detects displacement by moving the center rod horizontally according to a location where a center rod fixed to the first bracket and connected to the second bracket is provided and installed, a displacement meter body connecting the displacement meter body and the first bracket 1 link, a second link connecting the center rod of the displacement gauge body and the second bracket, and a friction force compensating member provided in the displacement gauge body to provide a physical stress to the center rod and cancel the friction force caused by the treatment of the center rod. Can include.

The sensor group includes a 10-channel digital indicator for measuring displacement fluctuations on a wall surface of the nuclear power plant containment building, a 10-channel thermocouple measuring temperature change for the nuclear power plant containment building, and a 5-channel RTD, and the nuclear power plant. It may include one or more of the two-channel pressure transmitter for applying a predetermined pressure to the power plant containment.

The central control server is an interface connected to the sensor group by wire or wireless to receive a plurality of measurement signals, and generates a pressure control signal for a verification test of the nuclear power plant containment to the sensor group through the interface, and , A test processor that transmits according to a measurement period, a calculator that calculates a verification test result by applying the plurality of measurement signals to an arithmetic algorithm, and a display that displays the verification test result on the screen.

The verification test may include a result of at least one of predicted displacement, allowable displacement, margin, and recovery rate.

The calculator, the following equation for the expected displacement,

It may include a predicted displacement calculation unit calculated according to.

The operator, the following equation for the allowable displacement,

It can be calculated according to.

The maximum pressure may vary from 0 psig to 69 psig in a 30 second cycle.

The operator, the following equation for the margin,

It can be calculated according to.

The correction factor may be set to 1.3.

The operator, the following equation for the recovery rate,

It can be calculated according to.

In addition, the structural integrity verification test method using a data collection system according to another embodiment of the present invention for solving the above-described problem is a nuclear power plant in which a sensor group including an extensometer measuring fluctuations for one or more displacement elements is installed. In the structural integrity verification test method for a power plant containment building using a data collection system, the step of transmitting a pressure control signal to the sensor group according to a measurement period, the sensor group for the nuclear power plant containment building for each measurement period It may include collecting the variation of the measured displacement element, and calculating a verification test result by applying the collected measurement signals to an algorithm.

The measurement period may be an interval of 30 seconds.

According to an embodiment of the present invention, it is connected to a sensor group including an extensometer to collect the measured variation of the displacement element, and based on the optimal algorithm, the structural integrity of the nuclear power plant containment building according to the displacement element variation value. There is an effect of providing an index in which the verification test results are accurately reflected.

1 is a diagram illustrating the structure of a conventional dome structure of a nuclear power plant.
2A is a diagram of an overall structure of a data collection system including an extender according to an embodiment of the present invention.
2B is a diagram of a sensor group included in a data collection system according to an embodiment of the present invention.
3 is a diagram of an extensometer included in a data collection system according to an embodiment of the present invention.
4 is a diagram illustrating the structure of a central control server included in a data collection system according to an embodiment of the present invention.
5 is a diagram illustrating a structure of an operator included in a central control server of a data collection system according to an embodiment of the present invention.
6 is a diagram illustrating a structural integrity verification test method using a data collection system according to an embodiment of the present invention.

Hereinafter, exemplary embodiments disclosed in the present specification will be described in detail with reference to the accompanying drawings, but identical or similar elements are denoted by the same reference numerals regardless of reference numerals, and redundant descriptions thereof will be omitted. The suffixes "module" and "unit" for constituent elements used in the following description are given or used interchangeably in consideration of only the ease of writing the specification, and do not themselves have a distinct meaning or role from each other.

In addition, in describing the embodiments disclosed in the present specification, when it is determined that a detailed description of related known technologies may obscure the subject matter of the embodiments disclosed in the present specification, the detailed description thereof will be omitted. In addition, the accompanying drawings are for easy understanding of the embodiments disclosed in the present specification, and the technical idea disclosed in the present specification is not limited by the accompanying drawings, and all changes included in the spirit and scope of the present invention , It should be understood to include equivalents or substitutes.

In addition, terms including ordinal numbers such as first and second may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another component.

When a component is referred to as being "connected" or "connected" to another component, it is understood that it may be directly connected or connected to the other component, but other components may exist in the middle. It should be. On the other hand, when a component is referred to as being "directly connected" or "directly connected" to another component, it should be understood that there is no other component in the middle.

In the present description, expressions in the singular include plural expressions, unless clearly defined otherwise in the context, and terms such as "includes" or "have" refer to features, numbers, steps, actions, components, and parts described in the specification. It is to be understood that it is intended to designate the existence of a combination of these and not to preclude the possibility of the presence or addition of one or more other features or numbers, steps, actions, components, parts, or combinations thereof.

In addition, the various techniques described herein may be implemented with hardware or software, or, where appropriate, with a combination of both. As used herein, terms such as "...unit", "...server" and "...system" are likewise a computer-related entity, i.e., hardware , It can be treated as a combination of hardware and software, software or equivalent to software at the time of execution. In addition, each function executed in the program of the present invention may be configured in a module unit, and may be recorded in one physical memory, or distributed between two or more memories and a recording medium.

Hereinafter, a data collection system including an extensometer according to an embodiment of the present invention and a structural integrity verification test method using the same according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 2A is a diagram of the overall structure of a data collection system including an extender according to an embodiment of the present invention, and FIG. 2B is a diagram of a sensor group included in the data collection system according to an embodiment of the present invention. .

2A and 2B, the data collection system of the present invention includes a sensor group 100 and a sensor installed in a nuclear power plant containment building 10 and including an extensometer that measures fluctuations for one or more displacement elements. Includes a central control server 200 that collects the variation of the displacement element measured by being connected to the group 100, and provides a result of a structural integrity verification test for the nuclear power plant containment building 10 based on the displacement element variation value. can do.

The sensor group 100 is a sensor group consisting of a plurality of sensors, and may be installed on an inner wall of an object to be tested for structural integrity, that is, a containment building of a nuclear power plant or a dome structure.

Components of the sensor group 100 include an extensometer 110 of a 60-channel device that measures linear displacement with respect to the doom structure, and a 10-channel Digimatic Indicator that measures displacement fluctuations on a wall. , 10 channels of thermocouple and 5 channels of RTD (Resistance Temperature Detector) that measure temperature changes in nuclear power plant containment buildings, and 2 channels of pressure transmitter that apply a predetermined pressure to the nuclear power plant containment building. The above may be included, and the sensor group 100 may measure variations in displacement, flatness, temperature, and the like with respect to the doom structure using these sensors.

In addition, the sensor group 100 may perform data communication with the central control server 200 through a repeater through a wired/wireless communication protocol, and transmit the measured result to the central control server 200 in real time.

The central control server 200 may be installed in or remotely from the nuclear power plant, and may be connected to the sensor group 100 through a wired or wireless communication network to receive a measurement signal.

In addition, the central control server 200 may generate a pressure control signal for applying a test pressure to the dome structure for a structural integrity verification test and transmit it to the sensor group side.

In particular, the central control server 200 according to an embodiment of the present invention applies the measurement signal transmitted by the sensor group 100 to a predetermined algorithm, and thus an Expected Displacement (ED) and an Allowable Displacement (DA). ), an acceptable rate (Margin; Mg) and a recovery rate (Recovery; Rv).

The above-described predicted displacement (EA) is a verification factor of the structural integrity verification test for the containment building of a nuclear power plant, and the maximum pressure applied to the containment building is gradually increased and lowered from 0 psig to 69 psig. By checking whether the displacement is restored within the reference value, the calculation algorithm of the present invention for calculating this calculates the verification result in consideration of the rate of temperature and pressure change.

Here, in the verification test, the test pressure applied to the object to be measured may be set to fluctuate in a 30 second cycle.

The central control server 200 can receive measurement signals transmitted in real time from one or more sensor groups without delay, calculate verification test results including expected displacements, etc. through a set calculation algorithm, and display them immediately on the screen. A high-performance and large-capacity server device can be used.

Hereinafter, a structure of an extensometer used in a data collection system according to an embodiment of the present invention will be described with reference to the drawings.

3 is a diagram of an extensometer included in a data collection system according to an embodiment of the present invention.

Referring to FIG. 3, the extensometer 110 of the present invention includes a first bracket 111 installed at a reference point of the nuclear power plant containment to provide support, and a second bracket 112 fixed to the nuclear power plant containment building. ), a center rod fixed to the first bracket 111 and connected to the second bracket 112 is provided, and the center rod moves horizontally according to the installed position, and the displacement meter body 114, which detects displacement, and the displacement meter body 114 It may include a first link 115 connecting the first bracket 111 and a second link 116 connecting the center rod of the displacement meter body 114 and the second bracket 112.

The first bracket 111 forms a reference point for measuring displacement while supporting one of both ends in the longitudinal direction of the displacement meter body 114, which will be described later, and is installed at the reference point and can provide a supporting force for installing one end of the displacement meter body 114. have.

The first bracket 111 may be coupled to the displacement meter body 300 via the first link 115.

The second bracket 112 is a component that is fixed to the object to be measured and supports the other end of the displacement meter body 114 in the longitudinal direction. The second bracket 112 is fixed to the object to be measured for displacement while forming a state horizontally facing the first bracket 111, and may support the other end of the displacement meter body 114.

The second bracket 112 may be coupled to the displacement meter body 114 via the second link 116 as a medium.

The displacement meter body 114 is a component that senses and measures the displacement of the object to be measured, and may be installed between the first bracket 111 and the second bracket 112, and a center rod connected to the second bracket 112 ( The displacement of the object to be measured can be measured through the horizontal movement of 113). In addition, the displacement gauge body 114 may include a displacement gauge housing, a load plate, a guide rod, a return spring, a solenoid coil, and a magnetic body.

According to the structure of the displacement meter body 114, the extensometer 110 may measure the displacement through the position of the magnetic body moving together with the center rod 113 according to the displacement of the object.

In addition, the displacement meter body 114 may be equipped with a friction force compensating member that provides a physical stress to the central bar and cancels the friction force caused by the treatment of the central bar.

Hereinafter, a structure of a central control server included in a data collection system according to an embodiment of the present invention will be described with reference to the drawings.

4 is a diagram illustrating the structure of a central control server included in a data collection system according to an embodiment of the present invention.

Referring to FIG. 4, the central control server 200 according to an embodiment of the present invention includes an interface 210 and an interface 210 that are connected to a sensor group by wire or wirelessly to receive a plurality of measurement signals ss. Through the sensor group, a pressure control signal (ts) is generated for a verification test for a nuclear power plant containment building, and a test processor 220 that transmits it according to a measurement period, and a plurality of measurement signals (ss) are applied to the calculation algorithm. It may include an operator 230 for calculating the verification test result and a display 240 for displaying the verification test result on the screen.

The interface 210 may be connected to a sensor group installed in a dome structure that is a verification test target through a wired or wireless communication network to receive the detected displacement and temperature fluctuations. The interface 210 supports various wired and wireless communication protocols, and may receive a measurement signal ss from a sensor group located in a near or remote location in real time and transmit it to the calculator 230.

The test processor 220 is installed on the dome structure and transmits a pressure control signal ts to a pressure transmitter that applies pressure so that the verification test is performed.

Accordingly, the test processor 220 may transmit the pressure control signal ts by connecting the above-described interface 210 to the pressure transmitter by wire or wirelessly.

The calculator 230 may calculate a verification test result by applying the calculation algorithm of the present invention to the measurement signal ss received by the central control server 200. The calculator 230 may be implemented in the form of a program that performs four arithmetic operations according to various equations, and may calculate a verification test result by inputting the measurement signal ss transmitted from the interface 210 into the program.

Here, the verification test is to calculate a result for at least one of the predicted displacement (ED), the allowable displacement (DA), the margin (Mg), and the recovery rate (Rv), and a specific calculation algorithm for calculating this will be described later.

The display 240 may display the calculated verification test result in numerical form on the screen. These verification test results can be displayed sequentially by date and time, and the applied maximum pressure (psig), temperature (temp), current measured by the sensor group (mA), and changed displacement (dip.) , The above-described predicted displacement (ED), allowable displacement (DA), margin (Mg), and recovery rate (Rv) may be classified and displayed.

Hereinafter, an operator included in the data collection system according to an embodiment of the present invention will be described with reference to the drawings.

5 is a diagram illustrating a structure of an operator included in a central control server of a data collection system according to an embodiment of the present invention.

Referring to Figure 5, the operator 230 of the central control server according to an embodiment of the present invention is a program that implements the algorithm of the present invention, recorded on a recording medium capable of reading and writing can be mounted on the central control server, It may be divided into an expected displacement calculation unit 231, an allowable displacement calculation unit 233, a margin calculation unit 235, and a recovery rate calculation unit 237.

In the following description, Displacement (Disp.) is defined by Equation 1 below.

In Equation 1 above,'ΔmA' denotes a'current measured displacement value (mA)-a measured displacement value before pressure (mA)'.

In addition,'B' is defined by Equation 2 below as'Corrected Calibration Factor (inch/mA)'.

In Equation 2 above,'K' is the displacement meter spring constant (lb/ft),'L' is the actual measurement (installation) length of the Invar Wire (ft), and'E' is the Invar Wire elastic modulus (psi), and'A''Invar Wire cross-sectional area (in ² ),'θ' indicates Invar Wire installation angle deviation from Center Point, and'β' indicates Scale Factor (inch/mA).

In addition, in Equation 1 again,'αth' is the Invar Wire thermal expansion coefficient (in/ft/℉),'L' is the Corrected Length (ft),'L'=L/cosθ', and'△T' is' It represents the current temperature (°F)-pre-pressurization temperature (°F)'.

In addition, the predicted displacement calculation unit 231 receives the current pressure, the maximum predicted displacement, and the maximum pressure, and calculates a displacement change predicted value due to pressure with respect to the measurement object, and the predicted displacement (ED) Can be calculated.

As an example, if the current pressure is 46.2, the maximum pressure that can be applied to the dome structure is 65.6, and the maximum expected displacement is 0.149, the expected displacement (ED) is calculated as 0.105 inch.

In addition, the allowable displacement calculation unit 233 receives the current pressure, the maximum expected displacement, the maximum pressure, and the initial pressure to calculate the allowable displacement value for the measurement object, and calculates the allowable displacement (AD) by Equation 4 below. Can be calculated.

Here, the correction factor may be set to 1.3, but is not limited thereto.

For example, if the current pressure is 46.2, the initial pressure is 0, the maximum pressure is 65.6, and the maximum expected displacement is 0.149, it is calculated as 0.136 inches.

The initial pressure is an initial set value and may correspond to atmospheric pressure.

In addition, the margin calculation unit 235 receives the current pressure and the maximum expected displacement and calculates the margin for the allowable range, and can calculate the margin Mg by Equation 5 below. .

Here, the correction factor may be set to 1.3.

As an example, if the current displacement is 0.14, the maximum expected displacement is 0.149, and the correction factor is 1.3, it is calculated as 27.723.

In addition, the recovery rate calculation unit 237 receives the measured maximum displacement and the measured maximum displacement after decompression and calculates the displacement recovery rate of the measurement object, and can calculate the recovery rate Rv by Equation 6 below. .

As an example, if the measured maximum displacement is 0.192 and the measured maximum displacement after decompression is 0.14, it is calculated as 27.083%.

Hereinafter, a method for verifying structural integrity by a data collection system according to an embodiment of the present invention will be described with reference to the drawings.

6 is a diagram illustrating a structural integrity verification test method using a data collection system according to an embodiment of the present invention.

6, the structural integrity verification test method according to an embodiment of the present invention is a data collection system for a nuclear power plant containment building in which a sensor group including an extensometer measuring fluctuations for one or more displacement elements is installed. In the structural integrity verification test method according to, the step of transmitting a pressure control signal to the sensor group according to the measurement period (S100), collecting the variation of the displacement element measured by the sensor group for the nuclear power plant containment building for each measurement period. A step S110 and a step S120 of calculating a verification test result by applying a plurality of measurement signals to an arithmetic algorithm. Here, the measurement period may be an interval of 30 seconds.

Specifically, in the step of transmitting the pressure control signal to the sensor group according to the measurement period (S100), the measurement target is to install and prepare a sensor group including an extensometer on the dome structure of a nuclear power plant, and apply pressure. Verification tests are performed.

At this time, the pressure applied to the dome structure transmits a pressure control signal so that the maximum pressure rises and falls stepwise from 0 psig to 69 psig.

Next, in the step (S110) of collecting the variation of the displacement element measured by the sensor group for the nuclear power plant containment for each measurement period, the measurement signal transmitted from the sensor group is collected in real time according to the step S100. Here, the measurement signal collected by the central control server corresponds to the measured displacement fluctuation value as the maximum pressure rises and falls in 30 cycles.

Subsequently, in the step of calculating the verification test result by applying the plurality of measurement signals to the calculation algorithm (S120), measurement values such as the current pressure, the maximum pressure, the current displacement, and the actual maximum displacement included in the measurement signal collected in real time are received. Then, the predicted displacement (ED), the allowable displacement (AD), the margin (Mg), and the recovery rate (Rv) are calculated by substituting this into the calculation algorithm defined in the calculator.

Although many items are specifically described in the above description, this should be interpreted as an illustration of a preferred embodiment rather than limiting the scope of the invention. Therefore, the invention should not be determined by the described embodiments, but should be determined by the claims and equivalents to the claims.

10: nuclear power plant containment building 100: sensor group
110: extensometer 120: Digimatic indicator
130: thermocouple 140: RTD
150: pressure transmitter 200: central control server
210: interface 220: test processor
230: calculator 231: predicted displacement calculation unit
233: allowable displacement calculation unit 235: margin calculation unit
237: recovery rate calculation unit 240: display

Claims (13)

A sensor group installed in a containment building of a nuclear power plant and including an extensometer for measuring fluctuations with respect to one or more displacement elements; And
A central control server connected to the sensor group and collecting the measured variation of the displacement element, and providing a result of a structural integrity verification test for the nuclear power plant containment building based on the variation value of the displacement element,
The extensometer is a 60-channel device that measures linear displacement for the nuclear power plant containment,
A first bracket installed at a reference point of the nuclear power plant containment building to provide a supporting force;
A second bracket fixed to the nuclear power plant containment building;
A displacement meter main body fixed to the first bracket and configured to detect displacement by horizontally moving the center rod according to a location where a center rod connected to the second bracket is provided and installed;
A first link connecting the displacement meter body and the first bracket;
A second link connecting the center rod of the displacement gauge body and the second bracket; And
A friction force compensating member provided in the displacement gauge body to provide a physical stress to the central bar and to offset the frictional force caused by the treatment of the central bar.
Data collection system comprising a. delete The method of claim 1,
The sensor group,
A 10-channel Digimatic indicator for measuring displacement fluctuations on the wall of the nuclear power plant containment building;
A 10-channel thermocouple and 5-channel RTD for measuring a temperature change of the nuclear power plant containment building; And
Two-channel pressure transmitter for applying a predetermined pressure to the nuclear power plant containment building
A data collection system including one or more of. The method of claim 1,
The central control server,
An interface connected to the sensor group by wire or wirelessly to receive a plurality of measurement signals;
A test processor for generating a pressure control signal for a verification test of the nuclear power plant containment building in the sensor group through the interface, and transmitting it according to a measurement period;
A calculator for calculating a verification test result by applying the plurality of measurement signals to an arithmetic algorithm; And
Display to display the verification test result on the screen
Data collection system comprising a. The method of claim 4,
The verification test,
A data collection system including a result of at least one of predicted displacement, allowable displacement, margin, and recovery rate. The method of claim 5,
The operator,
The following equation for the expected displacement,

A data collection system including an expected displacement calculation unit that is calculated according to. The method of claim 5,
The operator,
The following equation for the allowable displacement,

Data collection system including an allowable displacement calculation unit calculated according to. The method of claim 6 or 7,
The maximum pressure is,
A data acquisition system that varies from 0 psig to 69 psig in 30 second cycles. The method of claim 5,
The operator,
The following equation for the margin,

Data collection system including an allowable displacement calculation unit calculated according to. The method according to claim 7 or 9,
The correction factor is a data collection system set to 1.3. The method of claim 5,
The operator,
The following equation for the recovery rate,

Data collection system including a recovery rate calculation unit calculated according to. In the structural integrity verification test method using a data collection system for a nuclear power plant containment building in which a sensor group including an extensometer for measuring fluctuations of one or more displacement elements is installed,
Transmitting a pressure control signal to the sensor group according to a measurement period;
Collecting the variation of the displacement element measured by the sensor group for the nuclear power plant containment building for each measurement period; And
Step of calculating a verification test result by applying a plurality of collected measurement signals to a calculation algorithm
Structure integrity verification test method comprising a. The method of claim 12,
The measurement period is a structural integrity verification test method with an interval of 30 seconds.

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