JPH09113627A - Radiation source intensity measuring equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radiation source intensity measuring equipment in which the measurement of radiation source intensity can be grasped as a function of three- dimensional coordinate position by operating the three-dimensional coordinate position of a measuring point and the radiation source intensity from rotary driving amount and measured distance required for selecting the measuring point. SOLUTION: A desired measuring range is determined for an object 38 and a plurality of measuring points are selected by driving a rotary table 10 through a rotary driver 13 while irradiating the object 38 with a laser beam emitted from a laser beam range finder 9. The range finder 9 determines the distance between a reference point and a selected measuring point and then a computer 35 operates the three-dimensional coordinate position of each measuring point based on each distance thus determined and the rotary driving amount of driver 13. Subsequently, the rotary table 10 is driven 13 depending on the rotary driving amount at the time of selecting a measuring point to direct a radiation measuring unit 8 toward each measuring point before determining the radiation source intensity from each measuring point. Furthermore, solid angle of the measuring unit 8 is corrected for each measuring point. According to the invention, the measurement of radiation source intensity can be grasped as a function of three-dimensional coordinate values.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radiation source intensity measuring device, and more particularly to a three-dimensional radiation source intensity measurement for a pipe containing radioactive particles or radioactive fluid or related equipment in a radiation handling facility such as a nuclear power plant. The present invention relates to a radiation source intensity measuring device that measures a coordinate position.

[0002]

2. Description of the Related Art A conventional radiation source intensity measuring device displays a radiation source intensity on a plane by collimating and measuring the radiation.

[0003]

Therefore, since the measured data are only the two-dimensional coordinate data and the radiation dose, the radiation source intensity distribution can be used only for displaying in a plane, and the data is developed. It is in a situation where it is not used for a long time.

Further, as the measuring method, the range to be measured cannot be limited, so that the measuring method is performed by dividing the measuring area in a two-dimensional (X, Y) plane at equal intervals, which does not serve as a radiation source and measurement is unnecessary. Many places are included as measurement targets,
Therefore, there is a problem that the measurement time is long, for example, about 10 hours.

Therefore, the object of the present invention is to solve the above-mentioned problems of the prior art, to grasp the measured value of the radiation source intensity of the object to be measured as a function of the three-dimensional coordinate position, and to analyze the obtained data. It is possible to make advanced use such as use in a radiation dose distribution display system having a display function.

Further, it is also possible to omit the measurement of the measurement unnecessary area and shorten the measurement time by arbitrarily designating the measurement target range.

Another object is to reduce the exposure of the measurement operator by displaying the measurement result so that it can be visually recognized. Further, it is to make it possible to display the measurement result at the measurement site so that the workers concerned can be made aware of the environmental dose rate at the work site and the exposure of the workers concerned can be reduced.

[0008]

In order to achieve the above object, a radiation source intensity measuring apparatus according to the present invention comprises a radiation measuring device for detecting radiation emitted from an object to be measured, and a laser beam to the object to be measured. Laser beam range finder for irradiating a laser beam to measure a distance from a reference point to a laser irradiation point, a rotary table on which the radiation measuring instrument and the laser beam range finder are installed, and a measurement target of the measurement target A rotation driving unit that drives the rotary table while irradiating the measurement object with the laser beam to select a point, and also drives the rotary table to direct the radiation measuring instrument to the selected measurement point. A measurement result by the radiation measuring device, a rotation driving amount by the rotation driving means necessary for selecting the measurement point, and a measurement distance by the laser beam distance meter. Characterized in that it comprises calculating means for calculating a radiation source intensity in the measuring point and the three-dimensional coordinate positions of al the measuring point, a.

[0009] Further, preferably, there is provided display means for displaying the three-dimensional coordinate position calculated by the calculating means and the radiation source intensity corresponding to this coordinate position.

Further, the calculating means judges whether or not the radiation source intensity obtained by the calculation exceeds the allowable amount, and displays the coordinate position when the intensity exceeds the allowable amount on the display section.

Further, the rotating table is mounted on the second rotating table so as to be rotatable in a direction intersecting with the rotating direction of the rotating table, and the rotation driving means rotationally drives the second rotating table, The turntable is rotationally driven through the rotation of the second turntable.

Further, the radiation measuring device, so that the three-dimensional coordinate position on the object to be measured and the radiation source intensity corresponding to the coordinate position can be automatically obtained by remote control.
The laser beam range finder, the rotary base, the rotation drive means, and the automatic control means for automatically controlling the arithmetic means are provided.

I for observing the object to be measured
Equipped with a TV camera.

Further, a shielding box surrounding the radiation measuring device and the laser beam range finder is provided, and the shielding box is formed with an opening through which the radiation to be measured and the laser beam to be irradiated pass. The opening degree of the opening is adjusted by a diaphragm unit provided near the opening.

The opening degree is adjusted according to the size of the measuring range of the measuring object.

Further, the diaphragm means has a first diaphragm part for adjusting the opening degree in a direction intersecting with a rotation surface direction of the rotary table and a second diaphragm part for adjusting the opening degree in the same direction. .

Further, a laser beam moving means for moving the laser beam in a direction intersecting the direction of the rotation surface of the turntable is provided, and the opening / closing degree of the first diaphragm portion moves the laser beam by the laser beam moving means. Then, it is adjusted by irradiating the vicinity of the boundary of the measurement range on the object to be measured and opening and closing the first diaphragm portion until the laser irradiation point disappears.

Next, the operation of the present invention will be described.
A desired measurement range of the measurement object is determined, a laser beam of a laser beam range finder is irradiated, and a plurality of measurement points are selected. Obtain the distance from the reference point to the measurement point selected by the laser beam range finder, and know the rotation drive amount when the rotary base is rotationally driven by the rotation drive means to irradiate the laser beam to the selected measurement point. The calculation means calculates the value of the three-dimensional coordinate position of the measurement point for each selected measurement point. Next, in order to direct the radiation measuring instrument to the measurement point in order to obtain the radiation source intensity from the selected measurement point, the rotary base is rotationally driven corresponding to the rotational drive amount, and the radiation is measured from one selected measurement point. Then, the radiation source intensity is obtained, and then the radiation measuring instrument is directed to the adjacent measurement point to similarly obtain the radiation source intensity.
Since the solid angle or the like at which the radiation measuring instrument sees each measurement point is not uniform, correction is performed by the calculation means and the standardized radiation source intensity is obtained for each measurement point.

By displaying the three-dimensional coordinate position calculated by the calculating means and the radiation source intensity corresponding to this coordinate position by the display means, the radiation is visually radiated to the measuring object having a non-planar depth. The source intensity distribution is displayed, and it is used for the convenience of measuring personnel and field workers to reduce exposure to radiation, and it is also used for the advanced use of measurement results such as for use in a radiation dose distribution display system.

By judging whether or not the calculated radiation source intensity exceeds the allowable amount and displaying the coordinate position when it exceeds the allowable amount, it is provided for the convenience of reducing the radiation exposure of the measurer or the site worker. .

The turntable is mounted on the second turntable so as to be rotatable in a direction intersecting the rotation direction of the turntable. The rotation drive means directly drives the second rotary table to rotate, and the rotary table is driven to rotate via the second rotary table being driven to rotate.

By automatically measuring the radiation source intensity by remote control by the automatic control means, it is provided for the convenience of reducing the exposure of the measurer and the site worker.

By observing an object to be measured or a laser irradiation point on a monitor screen with an ITV camera, it is possible to use the monitor screen or the like instead of directly observing the object to be measured when performing various operations such as selecting a measuring point. It can be observed and remote control becomes easy.

The radiation from the object to be measured and the laser beam of the laser beam range finder pass through the opening of the shielding box, and the opening degree of the opening is adjusted by the diaphragm means.

The opening degree of the opening is adjusted according to the size of the measurement range of the measurement object, for example, the diameter or length of the tube which is the measurement object.

The first throttle unit adjusts the opening degree in a direction intersecting the direction of the rotation surface of the rotary table, and adjusts it to the diameter of the tube mainly in the direction of the rotation surface of the rotary table when the object is a measurement object. Adjust the opening degree of the opening.

The second throttle portion adjusts the opening degree in a direction parallel to the direction of the rotation surface of the rotary table, and is mainly used when a tube long in the direction intersecting the direction of the rotation surface of the rotary table serves as an object to be measured. The opening degree of the opening is adjusted according to the pipe diameter.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a radiation source intensity measuring apparatus of the present invention will be described below with reference to the drawings.

As shown in FIG. 3, there is an entrance 2 as an opening on the surface of the shielding box 1 in the direction of the object to be measured, and as shown in FIG. 1 or 2, a first diaphragm is provided outside the entrance 2. A collimator 3a with a diaphragm function as a portion and a collimator 3b with a diaphragm function as a second diaphragm portion are mounted inside.

As shown in FIG. 6, the collimator 3a with a diaphragm function includes shield plates 5a and 5b and a collimator driving device 6 as shown in FIG.
As shown in FIG. 7, the collimator 3b with the diaphragm function is composed of shield plates 5c and 5d and collimator driving devices 6c and 6d. Shielding plates 5a-5d
Has gear receiving rails 7a to 7d, respectively, which are connected to the gears of the collimator driving devices 6a to 6d.

Further, the ITV camera 4 is provided above the shielding box 1.
Is installed.

As shown in FIG. 2, a radiation measuring instrument 8 and a laser beam range finder 9 are mounted on a rotary table 10 inside the shielding box 1. Radiation measuring instrument 8 and laser beam range finder 9
Is turned toward the measurement point of the measuring object 38 through the entrance 2 by rotating the rotary table 10.

As shown in FIG. 4, a turntable notch 14 is provided in the turntable 10 as a space in which the laser beam distance meter 9 can rotate.

The turntable 10 is attached to the bottom of the shielding box 1 by a turntable support 11, and the turntable support 11 is shown in FIG.
A gear 12 is attached to the rotary table drive device 13 as shown in FIG. The rotary base 10 is configured to be independently rotatable by the rotary base drive device 13, and is configured to move integrally with the shield box 1 when the shield box 1 is rotated.

At the rear of the laser beam range finder 9, a range finder gear receiving rail 16 is provided, and the range finder gear receiving rail 16 is connected to a range finder driving device 15 installed on the rotary table 10. . The laser beam range finder 9 is fixed to a range finder rotary bearing 18 by a range finder rotary shaft 17, and is installed in a rotary base cutout 14.

The support 19 is composed of an outer table 20 and an inner table 21. The inner table 21 has a shield box 1
Inner table notch 22 as a space for rotating
Is provided.

The outer table 20 has legs 23 (23a to 23a).
d) is attached, and wheels 24 (24a to 24d) are attached to the legs 23a to 23d, respectively.

An inner table gear receiving rail 25 is provided on the outer periphery of the inner table 21 and is connected to an inner table drive device 26 attached to the outer table 20.

The inner table 21 has a shield box rotary bearing 27.
Is installed. A shield box drive gear 28 is attached to one side of the shield box 1 on its lateral surface. The shield box 1 is fixed to the shield box rotation bearing 27 by a shield box rotation shaft 29.

A shield box drive device 30 is attached to the inner table 21 and is connected to the shield box drive gear 28. A spirit level 31 is attached to the center of the bottom of the shielding box 1.

The ITV camera 4 is connected to the ITV driving device 33 by the operation cable 32 and to the monitor 34 by the signal cable 37. The laser beam range finder 9 is connected to a range finder control device 36 by an operation cable 40 and connected to a computer 35 by a signal cable 37.

The collimator drive devices 6a to 6d, the rotary base drive device 13, the distance meter drive device 15, the inner table drive device 26, and the shield box drive device 30 are connected to the computer 35 by the operation cable 32 and the signal cable 37. There is. The radiation measuring instrument 8 is connected to the computer 35 by a signal cable 37.

The operation of this embodiment will be described below.

First, the origin positioning and the initial setting will be described. This apparatus is moved to and installed at a location overlooking the entire measurement object 38. As the measurement object 38, FIG.
As shown as the measurement result in FIG. 1, it is assumed that the assembly is, for example, a plurality of horizontal pipes and vertical pipes. This is because, in fact, such an aggregate is often a measurement target in a radiation handling facility such as a nuclear power plant.

The inner table drive device 26 and the shield box drive device 30 are operated to adjust the shield box 1 to be horizontal. The position of the level 31 at this time is marked.
Further, the collimator driving devices 6a to 6d drive the shielding plate 5a and the like to fully open the entrance 2 and operate the rangefinder control device 36 to emit a laser beam from the laser beam rangefinder 9. Mark points on the wall that hit. The marked position information serves as a positioning mark for the next and subsequent measurements.

Next, the initial condition of the positional relationship is input and stored in the computer 35. The state where the level 31 and the laser beam correspond to the two marking positions as described above is the initial state of the positional relationship. In this state, the angular positions of the gears of the inner table drive device 26 and the shielding box drive device 30 correspond to the origin position in the three-dimensional XYZ coordinate system. The origin coordinates are set at the center position of the rotary table 10 in the initial state.

Next, the measurement points are set. For a measurement object 38, which is an assembly of a plurality of horizontal pipes and vertical pipes, a measurement start point and an end point are set for each pipe, and a measurement interval is set between the start point and the end point of each pipe. These pieces of information are input to the computer 35 and stored.

The start point and the end point of the measurement are set by driving the inner table driving device 26 and / or the shielding box driving device 30 to drive the laser beam of the laser beam rangefinder 9 to the measuring object 38.
It is performed while irradiating upward and confirming the laser irradiation point with the ITV camera 4. Inner table drive device 26 and / or shield box drive device 30 when selected as the start point or end point
The angular position data of is read and stored. The start point and the end point are set at the center portion in the pipe radial direction.

Next, collimators 3a and 3 with a diaphragm function
Adjust b. When the measurement object 38 is a pipe arranged horizontally, the shield plates 5a, 5b are opened and closed by the collimator driving devices 6a, 6b, and when it is a pipe arranged vertically, the collimator driving device. The shield plates 5c and 5d are opened and closed by 6c and 6d.

When the object 38 to be measured is a pipe arranged horizontally, the shield plates 5a and 5b are opened and closed as follows.

With the collimators 3a and 3b having the diaphragm function opened to the maximum, the irradiation point by the laser beam is set to IT.
While checking with the V camera 4, the distance meter driving device 15 is operated to align the irradiation point with the upper end of the measuring object 38.

Next, the collimator driving device 6a closes the shielding plate 5a and narrows it until just before the laser beam disappears. The angular position of the drive gear of the collimator drive device 6a at this time is stored in the computer 35.

Similarly, the irradiation point of the laser beam is aligned with the lower end of the object 38 to be measured, and then the shield plate 5b is closed by the collimator drive device 6b, and the laser beam is narrowed down until it disappears. The angular position of the drive gear of the collimator drive device 6b at this time is stored in the computer 35.

Similarly, the laser beam is applied to the object 3 to be measured.
Align with the center of the end point of 8 and use this position as the end point for computer 3
Store in 5. The opening and closing of the shielding plates 5a and 5b is also stored in the computer 35 by the same operation as the starting point.

When the object 38 to be measured is a pipe arranged in the vertical direction, the shield plates 5c and 5d are opened and closed by the collimator driving devices 6c and 6d, and the same adjustment is performed.

Next, the distance between the start point and the end point is divided into appropriate measurement intervals to set other measurement points. These measurement points are provided with start point and end point data and measurement interval data, and are calculated by the computer 35.

As described above, the start point, the end point, the measurement point, and the opening / closing degree of the entrance 2 are set for one pipe of the measuring object 38 which is an assembly of a plurality of horizontal pipes and vertical pipes. It

Similarly, for the other horizontal pipes or vertical pipes of the object to be measured 38, the start point, end point position, and diaphragm information are stored in the computer 35.

Thereafter, when the computer 35 is instructed to start the measurement, the radiation source intensity is automatically measured by the radiation measuring instrument 8 at each measuring point.

Next, the measurement results will be described. From the values of the angular positions of the inner table drive device 26 and the shielding box drive device 30 and the value of the measurement distance from the origin position measured by the laser beam range finder 9, the coordinate position of the measurement point in the three-dimensional XYZ coordinate system is determined. , Is calculated by the computer 35.

From the radiation dose rate measured by the radiation measuring device 8, the solid angle up to the target measurement point, the solid angle, the radiation area for radiating the radiation, etc. are taken into consideration at the measurement point. The radiation source intensity at is calculated by the computer 35.

The information on the positions of the inner table driving device 26 and the shielding box driving device 30 includes the respective rotation angles, the distances measured by the laser beam rangefinder 9, the angles of the collimators 3a and 3b with the diaphragm function, and the radiation measuring instrument. It is the radiation dose measured in 8. Table 1 shows an example in tabular form.
Shown in

[0063]

[Table 1] In Table 1, the angle θ1 regarding the vertical direction indicates the angular position automatically input from the shielding box drive device 30, and the angle θ2 regarding the horizontal direction indicates the angular position automatically input from the inner table drive device 26. The angle θ3 indicates the aperture of the shield plates 5a and 5b when the direction of the entrance 2 is seen from the center of the exit of the laser beam of the laser beam rangefinder 9, and the angle θ4 indicates the exit of the laser beam of the laser beam rangefinder 9. Shows the aperture of the shielding plates 5c and 5d as viewed from the center of the entrance 2 and L represents the distance from the origin obtained by measurement with the laser beam range finder 9 to the measurement point.

In the right half of Table 1, the coordinate position (x, y, z) in the three-dimensional coordinate system XYZ obtained from the radiation dose R measured by the radiation measuring device 8, the angular position and the distance L to each measurement point. , The width indicating the outer diameter of the pipe of the measuring object 38, and the intensity (bq / cm @ 2) of the radiation source are displayed. Coordinate position (x, y, z) and width, radiation source intensity (b
q / cm @ 2) is calculated by the computer 35.

Since these data are stored in the computer 35, if a calculation / display program is created,
The following processing and display are possible.

(1) It is possible to color-code each radiation source (pipe etc.) according to the radiation source intensity and display it three-dimensionally (visualization of radiation source intensity) (FIG. 8). (2) It is possible to display a radiation dose rate map of a certain space from the radiation source intensity of each radiation source (pipe etc.) (visualization of radiation dose rate map) (FIG. 9).

FIG. 8 shows an example of a three-dimensional stereoscopic display, and FIG. 9 shows an example of a radiation dose rate map display of a certain space.

As described above, according to this embodiment,
When measuring the radiation source intensity, not only the measured value of the radiation source intensity but also its position is grasped as a three-dimensional coordinate, and the data is used for a radiation dose distribution display system having an analysis display function. It can be used for.

Further, by arbitrarily designating the measurement target range, it is possible to shorten the measurement time and reduce the exposure of the measurement operator. Further, by displaying the measurement result on the spot, it is possible to make the environmental dose rate of the work place known to the people involved in the work, and it is possible to reduce the exposure of the work.

In the above-described embodiment, the rotary base 10 has the shield box drive device 30 on the inner table 21 as the second rotary base in a direction intersecting with the rotation direction of the rotary base column 11 of the rotary base 10. The inner table driving device 26 as a rotation driving means directly drives the inner table 21 itself to rotate so that the rotary table 10 can rotate.
Shows the case where the inner table 21 is rotationally driven via the rotational drive.
It is also possible to directly rotate itself by the rotation driving means.

[0071]

According to the structure of the present invention, it is possible to measure only the measurement points selected according to the shape of the object to be measured and not measure the points that do not need to be measured. It is possible to shorten the measurement time of the measurement.

Further, since the measured value of the radiation source intensity of the measurement object can be grasped as a function of the three-dimensional coordinate position, the obtained data can be displayed in the radiation dose distribution display system having the function of displaying the broken lines. It is possible to use it in an advanced way.

Further, since the measurement result is displayed so that it can be visually recognized, it is possible to reduce the exposure of the measurement operator, and it is also possible to display the measurement result at the measurement site so that the work-related It is possible to make workers aware of the environmental dose rate at the work site and reduce the exposure of workers involved in the work.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall outline of an embodiment of a radiation source intensity measuring apparatus of the present invention.

FIG. 2 is a sectional view showing the inside of the shielding box.

FIG. 3 is a plan view (a) and a side view (b) of an entrance portion of the shielding box.

FIG. 4 is a perspective view showing an outline of a turntable.

FIG. 5 is a plan view showing a turntable.

FIG. 6 is a plan view showing an outer portion of a collimator with a diaphragm function.

FIG. 7 is a plan view showing an inner portion of a collimator with a diaphragm function.

FIG. 8 is a diagram showing a radiation source intensity visualized by three-dimensionally displaying each radiation source (pipe etc.) in accordance with the radiation source intensity of a measurement object by color coding or the like.

FIG. 9 is a diagram showing an example in which a radiation dose rate map of the radiation source intensity of the measurement target is displayed.

[Explanation of symbols]

 1 Shield Box 2 Entrance 3 (3a, 3b) Collimator with Aperture Function 4 ITV Camera 5 (5a, 5b, 5c, 5d) Shield Plate 6 Collimator Drive 7 Gear Bearing Rail 8 Radiation Measuring Instrument 9 Laser Beam Distance Meter 10 Rotation Stand 11 Turntable support 12 Turntable gear 13 Turntable drive device 14 Turntable cutout portion 15 Distance meter drive device 16 Distance meter gear bearing rail 17 Distance meter rotary shaft 18 Distance meter rotary bearing 19 Support table 20 Outer table 21 Inner table 22 Inner table cutout 23 (23a, 23b, 23c, 23d) Leg 24 (24a, 24b, 24c, 24d) Vehicle 25 Inner table gear receiving rail 26 Inner table drive device 27 Shield box rotating bearing 28 Shield box drive gear 29 Shield Box Rotating Shaft 30 Shield Box Drive Device 31 Level 32 Operation Cable 33 TV driving device 34 monitors 35 computer 36 rangefinder control unit 37 a signal cable 38 measurement object

Claims (10)

[Claims] 1. A radiation measuring instrument for detecting radiation emitted from an object to be measured, a laser beam rangefinder for irradiating the object to be measured with a laser beam and measuring a distance from a reference point to a laser irradiation point, A rotary table on which a radiation measuring device and the laser beam range finder are installed, and the rotary table while irradiating the laser beam to the measurement object in order to select a measurement point to be measured of the measurement object. Rotation driving means for driving the rotary table so as to direct the radiation measuring instrument to the selected measurement point, and the measurement result by the radiation measuring instrument and the rotation necessary for selecting the measurement point. A three-dimensional coordinate position of the measurement point and a radiation source intensity at the measurement point are calculated from the rotational driving amount by the driving means and the measurement distance by the laser beam rangefinder. Radiation source intensity measuring device, characterized in that it comprises a means. 2. The radiation intensity measuring apparatus according to claim 1, further comprising display means for displaying a three-dimensional coordinate position calculated by the calculating means and a radiation source intensity corresponding to the coordinate position. . 3. The display means judges whether or not the calculated radiation source intensity exceeds an allowable amount, and displays the coordinate position when the intensity exceeds the allowable amount on the display unit.
The radiation intensity measuring device according to. 4. The rotary table is mounted on the second rotary table so as to be rotatable in a direction intersecting with the rotation direction of the rotary table, and the rotation driving means rotationally drives the second rotary table,
The radiation intensity measuring apparatus according to claim 1, wherein the rotary table is rotationally driven through rotation of the second rotary table. 5. The radiation measuring device, the laser beam range finder, and the three-dimensional coordinate position on the object to be measured and the radiation source intensity corresponding to the coordinate position are automatically obtained by remote control. The radiation source intensity measuring apparatus according to claim 1, further comprising an automatic control unit that automatically controls the rotating table, the rotation driving unit, and the computing unit. 6. The radiation intensity measuring apparatus according to claim 1, further comprising an ITV camera for observing the measurement object. 7. A shielding box surrounding the radiation measuring device and the laser beam range finder is provided, and an opening through which the radiation to be measured and the laser beam to be irradiated pass is formed in the shielding box, The radiation intensity measuring apparatus according to claim 1, wherein the opening degree of the opening is adjusted by a diaphragm unit provided near the opening. 8. The radiation intensity measuring apparatus according to claim 7, wherein the opening degree is adjusted according to the size of the measurement range of the measurement object. 9. The diaphragm means includes a first diaphragm part for adjusting the opening degree in a direction intersecting with a direction of a rotation surface of the turntable and a second diaphragm part for adjusting the opening degree in the same direction. The radiation intensity measuring device according to claim 7, wherein 10. A laser beam moving means for moving the laser beam in a direction intersecting a direction of a rotation surface of the turntable, wherein the opening / closing degree of the first diaphragm portion moves the laser beam by the laser beam moving means. The radiation according to claim 9, wherein the radiation is adjusted by irradiating the vicinity of the boundary of the measurement range on the measurement object and opening and closing the first diaphragm until the laser irradiation point disappears. Strength measuring device.