JPH1038940A - Radio anechoic chamber and test method for magnetic-field immunity - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a test method in which a magnetic-field immunity is tested easily by a method wherein a performance which is required as a radio anechoic chamber (an electromagnetic-field shielding performance, a site attenuation performance) is maintained with a specific configuration. SOLUTION: A radio anechoic chamber as a whole is surrounded with a shielding material 11 of a magnetic substance such as iron or the like. Then, various tile-shaped, wedge shaped or pyramid-shaped radio absorptive materials 12 are installed on a ceiling and on wall surfaces. In addition, a part of a floor face 13 is provided with a nonmagnetic-substance floor part 41, and the size of the nonmagnetic-substance floor part 41 is decided so as to be by a prescribed value or higher larger than the length and the breadth of the floor face of an object 20 to be tested. In this case, it is required that the nonmagnetic-substance floor part 41 is formed of a nonmagnetic material and of a shielding material. Thereby, even when a a support base composed of a nonmagnetic substance is not used, the object 20, to be tested, of a prescribed value or higher can be separated from the magnetic substance. Consequently, only when the object 20 to be tested is placed on the nonmagnetic-substance floor part 41, the magnetic field immunity at a power-supply frequency can be tested easily.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a test method for performing a magnetic field immunity test (magnetic field immunity) and an anechoic chamber for performing the test.

[0002]

2. Description of the Related Art Electromagnetic waves generated by various electronic devices interfere with the functions of other electronic devices.
ce) is a problem.

[0003] In order to solve this kind of problem, the radiation of electromagnetic waves (electromagnetic interference) generated from electronic equipment must be regulated, and the performance of equipment, devices or systems in an environment where electromagnetic interference exists exists. Providing the ability (immunity) that can operate without deterioration is important.

[0004] The above tests for EMI and immunity are collectively referred to as EMC (Electromagnetic Compatibility) tests, and an anechoic chamber is used for such tests.

[0005] This type of anechoic chamber, as shown in FIG.
The whole is surrounded by a shield material 11, and an electromagnetic wave absorber 12 is used for the wall surface and the ceiling surface. There is also an anechoic chamber using a radio wave absorber on the floor. In the above test, a broadband electromagnetic wave is measured, but generally an electromagnetic wave on the order of MHz or GHz is targeted.

[0006]

However, in recent years, international standards have been issued for the magnetic field immunity test at the power supply frequency, and therefore, it has become necessary to give consideration to it.

In a magnetic field immunity test at a power supply frequency specified by the IEC (International Electrotechnical Commission), it is specified that a test object is separated from a magnetic body by at least 1 m.

However, since the floor of the anechoic chamber requires strength, a magnetic material such as iron or ferrite is sometimes used as a shield material. Therefore, when performing a magnetic field immunity test at the power supply frequency in such a situation, as shown in FIG.
It is necessary to prepare a non-magnetic support table (such as a wooden desk) 30 having a height of 10 mm and mount the DUT 20 on the support table 30.

When the test object is heavy or placed on the floor, the test cannot be performed in an anechoic chamber having a magnetic floor. The test was performed after moving to a room (for example, outside an anechoic chamber).

However, when the test object is a heavy object, a great deal of labor is required for movement and installation. For example, a CT device or MRI device of a medical device may require half a day for movement, installation, and removal.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object the performance required in an anechoic chamber (electromagnetic shielding performance, site attenuation (propagation loss between transmitting and receiving antennas in a measurement field) performance). ) To realize an anechoic chamber and a test method that can easily perform a magnetic field immunity test while maintaining the above conditions.

[0012]

Accordingly, the present invention, which is a means for solving the problems, is configured as described below.

(1) A first aspect of the present invention is an anechoic chamber having a wall surface and a ceiling surface for absorbing electromagnetic waves, and a part of the floor surface in a range which is larger than a vertical and horizontal length of the bottom surface of the DUT by a predetermined value or more. An anechoic chamber characterized by being made of a non-magnetic material.

In the anechoic chamber according to the first aspect of the present invention, a part of the floor surface is made of a non-magnetic material in a range that is larger than the vertical and horizontal dimensions of the bottom surface of the test object by a predetermined value, so that the test object is covered by a predetermined value or more. It becomes possible to separate the test object and the magnetic body.

(2) A second invention is an anechoic chamber having a wall surface and a ceiling surface for absorbing electromagnetic waves, wherein the anechoic chamber has a mounting surface having an area at least equal to the bottom surface of the DUT. A radio anechoic chamber characterized in that a portion above a predetermined value in a downward direction is made of a non-magnetic material.

In the anechoic chamber according to the second aspect of the present invention, even if the DUT cannot be separated from the floor of the anechoic chamber by a predetermined value due to the large bottom area of the DUT, the downward direction of the mounting surface is maintained. Since the portion of the predetermined value is made of a non-magnetic material,
By raising the test object from the floor surface, it becomes possible to separate the test object from the magnetic body by a predetermined value or more.

(3) A third invention is a magnetic field immunity test method for performing a magnetic field immunity test in an anechoic chamber provided with a lifter made of a non-magnetic material on a part of a floor surface,
The lifter is placed at the same height as the floor surface, a predetermined insulator support is placed on the lifter, and the lifter is lowered until the upper surface of the insulator support is at the same height as the floor surface. Place a test object for floor placing on the upper surface of the material, raise the lifter until the lifter is the same height as the floor surface in a state where the test object and the insulator support material are placed, A magnetic field immunity test method characterized by performing a magnetic field immunity test of a test object to be placed on a floor.

In the magnetic field immunity test method according to the third aspect of the present invention, first, a lifter is placed at the same height as the floor surface, and a predetermined insulator support is placed on the lifter, and the upper surface of the insulator support is placed on the floor. The lifter is lowered to the same height as the surface, and a test object for floor placing is placed on the upper surface of the insulator support material which has thus become the same height as the floor surface, and The lifter is raised up to the same height as the floor with the insulator and the insulator support placed thereon, and in this state, the magnetic field immunity test is performed on the specimen to be placed on the floor.

With respect to floor-standing equipment, it is prescribed that a magnetic field immunity test is performed by placing a test object on an insulating support material having a predetermined height. By placing the specified insulator support on the lifter, the insulator support can be moved easily, and the lifter is lowered until the upper surface of the insulator support is flush with the floor. By placing the test object for floor placement on the upper surface of the insulator support member having the same height as the floor in this manner, the test object can be easily moved.

(4) A fourth invention is a magnetic field immunity test method for performing a magnetic field immunity test in an anechoic chamber provided with a lifter made of a non-magnetic material on a part of a floor surface,
The test object was placed on the lifter with the lifter at the same height as the floor surface, and the distance between the floor surface and the test object mounting surface of the lifter was determined so that the test object and the magnetic body were separated from each other. A magnetic field immunity test method comprising raising a lifter on which a device under test is mounted until a predetermined value is reached, and performing a magnetic field immunity test on the device under test.

In the magnetic field immunity test method according to the fourth aspect of the present invention, first, the test object is placed on the lifter with the lifter at the same height as the floor surface, and the floor surface and the test object mounting surface of the lifter are placed on the lifter. The lifter is raised until the distance of the test object reaches a predetermined value that is set to separate the test object and the magnetic body, and in this state, the magnetic field immunity test of the test object to be placed on the floor is performed.

As described above, the lifter made of a non-magnetic material is raised until it reaches a predetermined value that is set so as to separate the test object from the magnetic material, so that the test object is moved to the dark room floor of the magnetic material. It can be separated from the surface by a predetermined distance. Therefore,
It is possible to test a large test object having a bottom surface comparable to the lifter mounting surface.

(5) The invention as a modified example of the second invention described above is an electromagnetic wave anechoic chamber having a wall surface and a ceiling surface for absorbing electromagnetic waves, and has a mounting area at least equal to the bottom surface of the DUT. An anechoic chamber having a mounting surface, a portion below a mounting surface having a value equal to or greater than a predetermined value is formed of a nonmagnetic material, and a lifter capable of ascending above the floor surface is provided.

In the anechoic chamber according to the present invention, even if the test object cannot be separated from the floor of the anechoic chamber by a predetermined value due to the large bottom area of the test object, the test object can be moved downward by a predetermined value. Since the value portion is made of a non-magnetic material, it is possible to separate the test object from the magnetic material by a predetermined value or more by raising the test object from the floor surface by the lifter.

[0025]

Embodiments of the present invention will be described below in detail with reference to the drawings. <First Embodiment> Here, FIG. 1 is a sectional view showing a schematic configuration of an anechoic chamber as a first embodiment of the present invention, and FIG. 2 is a sectional view showing one embodiment of the present invention. It is a top view which shows schematic structure of an anechoic chamber.

In these figures, reference numeral 10 denotes an anechoic chamber, which is entirely surrounded (ceiling, floor surface, wall surface) by a magnetic shielding material 11 such as iron. Various electromagnetic wave absorbers 12 such as tiles, wedges, or pyramids are provided on the ceiling and wall surfaces.

The shield material 11 on the wall surface or the ceiling surface may not be a magnetic material, but a magnetic material such as iron or ferrite is used because the floor surface of the anechoic chamber requires strength.

A non-magnetic floor 41 is provided on a part of the floor 13 made of a magnetic shielding material 11 such as iron. Note that the size of the nonmagnetic floor portion 41 is determined to be larger than the bottom surface of the DUT 20 by a predetermined value or more. The predetermined value means a distance (at least 1 m or more) between the test object and the magnetic body in the case of a magnetic field immunity test at a power supply frequency determined by IEC.
Therefore, in the example shown in FIG. 2, the size of the non-magnetic material floor 41 is determined so that the distance a to d between the bottom end of the DUT 20 and the end of the non-magnetic material floor 41 is 1 m or more. . In addition, both the lower direction and the lower direction of the nonmagnetic floor 42 are made of a nonmagnetic material. For example, in the case of concrete, care should be taken not to use reinforcing bars or steel frames.

In this case, regarding the non-magnetic material floor 41,
It must be a non-magnetic material and a shielding material. Therefore, a material such as copper, aluminum, non-magnetic stainless steel, or a material obtained by applying or coating the metal to a highly rigid engineering plastic can be used. From the point of compatibility of strength and shielding, SUS3
It is preferable to use 16 stainless steel materials.

As described above, a part of the floor surface (magnetic material) is made of a non-magnetic material in a range larger than the vertical and horizontal dimensions of the bottom surface of the DUT by a predetermined value or more. It is possible to separate the device under test 20 from the magnetic material by a predetermined value or more without using the above.

Accordingly, the DUT 20 is moved to the non-magnetic floor portion 41.
Simply by mounting on the top, the magnetic field immunity test of the power supply frequency can be easily performed without changing the performance required in the anechoic chamber.

<Second Embodiment> Next, a second embodiment of the present invention will be described. Here, FIG. 3 is a flowchart showing a processing procedure of a magnetic field immunity test method as a second embodiment of the present invention, and FIG. 4 is a schematic diagram of an anechoic chamber as a second embodiment of the present invention. It is sectional drawing which shows a structure.

First, the configuration of the anechoic chamber of this embodiment will be described with reference to FIG. In these figures, reference numeral 10 denotes an anechoic chamber, which is entirely surrounded (ceiling, floor surface, wall surface) by a magnetic shielding material 11 such as iron. Various electromagnetic wave absorbers 12 such as tiles, wedges, or pyramids are provided on the ceiling and wall surfaces.

A hole is provided in a part of the floor 13 made of a magnetic shielding material 11 such as iron, and a lifter 40 made of a non-magnetic material is provided in this hole. ing.

The lifter 40 is used to move equipment from a separate room provided below the anechoic chamber 10 to the anechoic chamber 10 or vice versa. is there. However, in FIG. 4, a detailed configuration of a separate room below the floor is omitted.

The lifter 40 is provided with a table 42 which can be moved up and down. When the DUT 20 is placed on the table 42, the lifter 40 can be at the same height as the floor 13 or can be raised or lowered. .

Since the lifter 40 is made of a non-magnetic material, it does not affect the magnetic field.
Also, do not have anything that affects the magnetic field immunity test (thing that not only generates a magnetic field but also disturbs the distribution of the magnetic field), such as one that causes magnetic coupling (a coil, etc.) Is preferred.

The size of the table 42 is determined so as to be larger than the bottom surface of the DUT 20 by a predetermined value or more as described with reference to FIG. Note that the predetermined value is
In the case of a magnetic field immunity test at a power supply frequency determined by the IEC, it means a distance (at least 1 m or more) between a test object and a magnetic body.

In this case, the table 42 needs to be a non-magnetic material and a shielding material.
Therefore, materials such as copper, aluminum, and non-magnetic stainless steel,
Alternatively, a material obtained by applying or coating the metal to a highly rigid engineering plastic can be used. From the point of compatibility between strength and shielding, SUS316
It is preferable to use a stainless steel material.

The lifter 40 is also made of a non-magnetic material at least for the predetermined value in the downward direction. The lifter 40 has a function of maintaining the shielding performance of the anechoic chamber when the table 42 is stopped at the initial position shown in FIG.

As described above, a part of the floor surface (magnetic material) is made of a non-magnetic material in a range larger than the vertical and horizontal dimensions of the bottom surface of the DUT by a predetermined value or more. It is possible to separate the device under test 20 from the magnetic material by a predetermined value or more without using the above.

Accordingly, the magnetic field immunity test of the power supply frequency can be easily performed while maintaining the performance required in the anechoic chamber only by placing the DUT 20 on the table 42.

Here, the procedure of the magnetic field immunity test in the anechoic chamber will be described with reference to the flowchart of FIG. In the present embodiment, an example will be described in which the IEC1000-4-8 test is performed using a floor-standing device. In this test, it is specified that the test is performed after placing the device under test on an insulating support material having a predetermined height for floor-standing equipment.

First, as an initial adjustment, the lifter 40 is operated so that the table 42 (lifter mounting surface) is at the same height as the floor surface 13 of the anechoic chamber (S1, S2 in FIG. 3). still,
In a normal case, the table 42 and the floor 13 have the same height in the initial state.

Then, the insulator support member 31 having a predetermined height is placed on the table 42 (S3 in FIG. 3). The insulator support material 31 having the predetermined height is required in the IEC1000-4-8 test, and has a height of 10 cm arranged between the floor and the test object when testing a floor-standing device. It is a support material of the insulator.

After placing the insulator support 31 on the table 42, the lifter 40 is lowered (S4 in FIG. 3) so that the upper surface of the insulator support 31 is at the same height as the floor 13 of the anechoic chamber. The lowering of the lifter 40 is controlled (S5 in FIG. 3).

Here, the DUT 20 is placed on the upper surface of the insulator support member 31 (S6 in FIG. 3). In this state, the upper surface of the insulator support member 31 is at the same height as the floor surface 13 of the anechoic chamber, so that the test object 20 placed on the floor surface 13 is slidably moved to slide the test object. The object 20 can be easily moved onto the insulator support 31.

Then, the lifter 40 is raised (FIG. 3S
7) The lifter 40 is operated such that the table 42 is at the same height as the floor 13 (S8 in FIG. 3). At the time when the operation of the lifter 40 is completed (the state shown in FIG. 2), a magnetic field immunity test is executed according to a procedure defined by rules (S9 in FIG. 3). In this magnetic field immunity test, an induction coil (not shown) is arranged in the anechoic chamber 10 to generate a magnetic field of a power supply frequency, and it is examined whether the function of the device under test 20 can be maintained under the magnetic field.

By performing the magnetic field immunity test according to the above procedure, it is possible to separate the DUT 20 from the magnetic material by a predetermined value or more without using a non-magnetic desk or the like for a heavy object placed on the floor. Will be possible. Even when using the insulator support material of a predetermined height, the test object is moved after the upper surface of the insulator support material is made equal to the floor surface by using the elevation of the lifter. Therefore, installation of a heavy object becomes extremely easy.

Therefore, the magnetic field immunity test at the power supply frequency can be easily performed while maintaining the performance required in the anechoic chamber. <Third Embodiment> Next, a third embodiment of the present invention will be described with reference to FIGS. Here, an embodiment in which a relatively large device is mounted on the table 42 will be described. Unlike the case of FIG.
An example in which a test object having a full bottom surface of the mounting surface of the table 42 is mounted will be described.

First, the insulating material 31 is placed on the table 42.
Is placed (FIGS. 5S1 to 5S), the insulator support member 31 is set at the same height as the floor surface 13 (FIGS. 5S4 to 5). Then, the DUT 20 is placed on the upper surface of the insulator support member 31 (S6 in FIG. 5). In this state, the upper surface of the insulator support member 31 is at the same height as the floor surface 13 of the anechoic chamber, so that the test object 20 placed on the floor surface 13 is slidably moved to slide the test object. The object 20 can be easily moved onto the insulator support 31.

The DUT 20 used in this embodiment is large, and when the table 42 is at the same height as the floor, the DUT and the magnetic material (floor 13) are used. Distance does not satisfy the requirements of the magnetic field immunity test defined by the IEC.

Then, the lifter 40 is raised as shown in FIG. 6 so that the mounting surface of the table 42 is separated from the floor surface 13 by a predetermined distance h (1 m) or more (FIGS. 5S7 to S7).
8). At the time when the operation of the lifter 40 is completed (the state shown in FIG. 6), a magnetic field immunity test is executed according to a procedure defined by rules (S9 in FIG. 5). In this magnetic field immunity test, an induction coil (not shown) is arranged in an anechoic chamber 10 to generate a magnetic field of a power supply frequency,
To see if it can maintain its function under the magnetic field.

By performing the magnetic field immunity test according to the above-described procedure, it is possible to separate the DUT 20 from the magnetic material by a predetermined value or more without using a nonmagnetic desk or the like for a large floor-standing device. Will be possible. Even when using the insulator support material of a predetermined height, the test object is moved after the upper surface of the insulator support material is made equal to the floor surface by using the elevation of the lifter. Therefore, installation of a heavy object becomes extremely easy. Since the table 42 is raised and separated from the magnetic floor 13 by a predetermined distance, the size of the non-magnetic table 42 can be used to the maximum extent.

Accordingly, the magnetic field immunity test at the power supply frequency can be easily performed while maintaining the performance required in the anechoic chamber. <Other Embodiments> The non-magnetic floor portion 41 in the first embodiment described above may be configured as a part of a rotatable turntable. Since various tests in an anechoic chamber are often performed on a turntable, a part of the turntable is thus placed on the nonmagnetic floor 4.
The configuration of 1 makes it extremely easy to shift from another test to a magnetic field immunity test.

In the above-described second and third embodiments, when the table 42 is raised,
It is also possible to provide a bottom plate 43 under the table 42 in order to prevent the hole from being opened.

That is, as shown in FIG. 7, when the table 42 is raised to the height h, the bottom plate 43 provided on the lifter may be at the same height as the floor 13.
The bottom plate 43 is also preferably made of a non-magnetic material, and more preferably made of SUS316 or the like so as to have a shielding property. The table 42 and the bottom plate 4
In the case where the bottom plate 43 is separated by a height h or more, there is no problem even if the bottom plate 43 is made of a magnetic material.

The nonmagnetic floor 41 and the table 42 of the anechoic chamber of each of the first to third embodiments are EM.
It is also possible to apply to the shield room for the C test. Further, in the shielded room applied in this manner, the nonmagnetic floor portion 41 may be configured as a part of the turntable as described above.

[0059]

As described above in detail with the embodiments, according to the inventions described in this specification, the following effects can be obtained.

(1) In the anechoic chamber according to the first aspect of the invention, a part of the floor surface is made of a non-magnetic material in a range larger than the vertical and horizontal lengths of the bottom surface of the test object by a predetermined value. As described above, it is possible to separate the test object from the magnetic body. Therefore, the magnetic field immunity test can be easily performed while maintaining the performance required in the anechoic chamber.

(2) The anechoic chamber according to the second aspect of the present invention has a large bottom area, so that the test object cannot be separated from the floor of the anechoic chamber by a predetermined value even if the test object cannot be separated from the floor. Since the portion of the predetermined value in the downward direction is made of a non-magnetic material,
By raising the test object from the floor surface, it becomes possible to separate the test object from the magnetic body by a predetermined value or more. Therefore, the magnetic field immunity test can be easily performed while maintaining the performance required in the anechoic chamber.

(3) In the magnetic field immunity test method according to the third aspect of the present invention, it is specified that the device to be tested is placed on an insulating support member having a predetermined height to perform a magnetic field immunity test for floor-standing equipment. Therefore, first, the lifter is placed at the same height as the floor surface and the predetermined insulator support is placed on the lifter, so that the insulator support can be easily moved. By lowering the lifter until the height is the same as the floor surface, by placing a test object for floor placement on the upper surface of the insulator support material that has become the same height as the floor surface in this way, The movement of the DUT becomes easy. Therefore, the magnetic field immunity test can be easily performed while maintaining the performance required in the anechoic chamber.

(4) In the magnetic field immunity test method according to the fourth invention, first, the test object is placed on the lifter with the lifter at the same height as the floor surface, and the test object is placed on the floor surface and the lifter. The lifter is raised until the distance from the surface reaches a predetermined value determined to separate the DUT from the magnetic body, and the magnetic field immunity test is performed on the DUT in this state. . In this way, the lifter made of a non-magnetic material is raised until it reaches a predetermined value that is set so as to separate the test object and the magnetic material. Can be separated by a distance of Therefore,
It is possible to test a large test object having a bottom surface comparable to the lifter mounting surface. Therefore, the magnetic field immunity test can be easily performed while maintaining the performance required in the anechoic chamber.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an anechoic chamber according to a first embodiment of the present invention.

FIG. 2 is a plan view showing an anechoic chamber according to the first embodiment of the present invention.

FIG. 3 is a flowchart illustrating a procedure according to a second embodiment of the present invention.

FIG. 4 is a sectional view showing an anechoic chamber according to a second embodiment of the present invention.

FIG. 5 is a flowchart illustrating a procedure according to a third embodiment of the present invention.

FIG. 6 is a sectional view showing an anechoic chamber according to a third embodiment of the present invention.

FIG. 7 is a perspective view showing an anechoic chamber according to another embodiment of the present invention.

FIG. 8 is a sectional view showing a conventional anechoic chamber.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Anechoic chamber 11 Shielding material 12 Electromagnetic wave absorbing material 13 Floor surface 20 DUT 40 Lifter 41 Non-magnetic material floor 42 Table

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Atsushi Watanabe 127 GYokogawa Medical System Co., Ltd.

Claims (4)

[Claims] 1. An anechoic chamber having a wall surface and a ceiling surface for absorbing an electromagnetic wave, wherein a part of the floor surface is made of a non-magnetic material in a range that is larger than a predetermined value from the vertical and horizontal directions of a bottom surface of a test object. An anechoic chamber characterized by: 2. An anechoic chamber having a wall surface and a ceiling surface for absorbing an electromagnetic wave, having a mounting surface having an area at least equal to the bottom surface of the DUT, and a predetermined value or more in a downward direction of the mounting surface. An anechoic chamber characterized by the fact that the portion is made of a non-magnetic material. 3. A magnetic field immunity test method for performing a magnetic field immunity test in an anechoic chamber provided with a lifter made of a non-magnetic material on a part of a floor surface, wherein the lifter is set at the same height as the floor surface. A predetermined insulator support is placed on the insulator support, and the lifter is lowered until the upper surface of the insulator support is at the same height as the floor surface. The lifter is raised until the height of the lifter becomes the same as the floor surface in a state where the test object and the insulator support member are mounted, and the magnetic field immunity test of the test object for floor placement is performed. A magnetic field immunity test method. 4. A magnetic field immunity test method for performing a magnetic field immunity test in an anechoic chamber provided with a lifter made of a non-magnetic material on a part of a floor surface, wherein the lifter is set at the same height as the floor surface. Place the test object on the top, until the distance between the floor surface and the test object mounting surface of the lifter reaches a predetermined value that is set to separate the test object and the magnetic body.
A magnetic field immunity test method comprising raising a lifter on which a device under test is mounted and performing a magnetic field immunity test on the device under test.