Portable radiation monitor

Abstract

The utility model provides a portable radiation monitor, which comprises a shell (100), radiation detectors (10, 20), a circuit board, a display screen (50) and a battery (61), the radiation detectors (10, 20), the circuit board, the display screen (50) and the battery (61) are arranged in the shell (100), the shell (100) is formed by an aluminum alloy plate with the thickness of 3mm-6mm and is subjected to conductive oxidation treatment, the radiation detectors (10, 20) are packaged by metal shielding sheets, and the metal shielding sheets are arranged in the shell (100). A transparent metal film is arranged on the surface of the display screen (50), the battery (61) is arranged in a battery bin made of a conductive material, and a battery cover (103) made of the conductive material and the shell are assembled in a tight fit mode. Therefore, interference of an electric field or an electromagnetic field can be effectively shielded.

Description

Technical Field

[0001] This utility model relates to a portable radiation monitoring instrument, and more particularly to a portable radiation monitoring instrument with an electromagnetic shielding structure. Background Technology

[0002] With the development of science and technology and the expansion of human activities, radiation issues have received increasing attention. Radiation monitors are capable of monitoring radiation dose, quickly and accurately detecting radiation dose rates in different environments. This helps people understand the radiation levels in their environment, provides guidance on environmental radiation safety, and effectively prevents and controls radiation hazards. Portable radiation monitors can be used in complex environments, and their reliability and anti-interference performance are increasingly valued. Currently, existing portable radiation monitors have poor resistance to strong electromagnetic interference. In strong electromagnetic environments, they are severely interfered with, resulting in inaccurate dose rate measurements, and some devices may even be damaged, causing functional failure.

[0003] To address the aforementioned problems and improve the accuracy, reliability, and anti-interference performance of portable radiation monitors, an electromagnetic shielding structure for portable radiation monitors is proposed. Utility Model Content

[0004] This utility model includes the following technical solutions.

[0005] The portable radiation monitor of this utility model includes a shell and a radiation detector, a circuit board, a display screen, and a battery disposed in the shell. The shell is made of an aluminum alloy plate with a thickness of 3mm to 6mm and is subjected to conductive oxidation treatment. The radiation detector is encapsulated with a metal shielding sheet. The surface of the display screen is provided with a transparent metal film. The battery is disposed in a battery compartment made of conductive material, and the battery cover made of conductive material is tightly fitted and assembled with the shell.

[0006] Preferably, the housing is provided with an SMA antenna opening for mounting an SMA antenna and an aviation plug opening for mounting an aviation plug, each of which is equipped with a metal sealing cap.

[0007] Preferably, conductive adhesive for sealing is provided at the locations of the battery cover, the display screen, the SMA antenna opening, and the aviation plug opening on the housing.

[0008] Preferably, a shielding cover made of aluminum plate is provided on the circuit board.

[0009] Preferably, an external ground wire consisting of a grounding point and a grounding wire is provided on the outside of the housing, a digital ground wire is provided in the digital circuit section of the circuit board, and an analog ground wire is provided in the analog circuit section of the circuit board.

[0010] Preferably, the digital ground wire and the analog ground wire are single-point grounded, and a ferrite bead is used for single-point connection.

[0011] Preferably, the circuit board has a 6-layer board topology, wherein the top and bottom layers are ground layers, and the middle 4 layers are signal layers.

[0012] Preferably, the circuit board includes a main controller processing unit, a detector signal processing unit, a display unit, and a positioning communication unit, with each unit arranged separately and shielded and isolated from each other.

[0013] Technical effects of utility model

[0014] This portable radiation monitoring instrument improves the accuracy, reliability, and anti-interference capability of radiation measurement by using an aluminum alloy shell of a certain thickness for the electromagnetic shielding structure, a reasonable circuit board design and layout, and a complete shielding design. Attached Figure Description

[0015] Figure 1 This is a front view of the portable radiation monitor of this utility model.

[0016] Figure 2 This is an AA cross-sectional view of the portable radiation monitoring instrument of this utility model.

[0017] Figure 3 This is a rear view of the portable radiation monitoring instrument of this utility model.

[0018] Figure 4 This is a side cross-sectional view of the display screen of the portable radiation monitor of this utility model.

[0019] Figure 5 This is a BB cross-sectional view of the portable radiation monitoring instrument of this utility model.

[0020] Figure 6 This is a block diagram of the main electrical structure of a portable radiation monitor according to one embodiment of the utility model. Detailed Implementation

[0021] The term "embodiment" used herein, as an example, is not necessarily to be construed as superior to or better than other embodiments. Performance testing in the embodiments of this application, unless otherwise specified, employs conventional testing methods in the art. It should be understood that the terminology used in this application is merely for describing particular implementations and is not intended to limit the scope of this disclosure.

[0022] Unless otherwise stated, the technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; other experimental methods and technical means not specifically mentioned herein refer to experimental methods and technical means commonly used by one of ordinary skill in the art.

[0023] In this document, conjunctions such as “comprising,” “including,” “with,” “having,” “containing,” “involving,” and “accommodating” within the scope of the claimed rights are understood to be open-ended, meaning “including but not limited to.” Only the conjunctions “consisting of” and “composed of” are closed-ended conjunctions.

[0024] To better illustrate the content of this application, numerous specific details are provided in the following detailed embodiments. Those skilled in the art should understand that this application can be implemented even without certain specific details. In the embodiments, some methods, means, instruments, and devices well-known to those skilled in the art are not described in detail in order to highlight the main points of this application.

[0025] Without conflict, the technical features disclosed in the embodiments of this application can be combined arbitrarily, and the resulting technical solutions belong to the content disclosed in the embodiments of this application. It should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" used in this application indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing technical features and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model unless they conflict with the context. In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance unless they conflict with the context.

[0026] The specific embodiments of this utility model are described below to enable those skilled in the art to understand this utility model. However, it should be understood that this utility model is not limited to the scope of the specific embodiments. For those skilled in the art, as long as the various changes are within the scope of the claims and the defined spirit and scope of this utility model, these changes are obvious. All utility model creations utilizing the concept of this utility model are protected.

[0027] First refer to Figure 6 This invention describes the main electrical structure of a portable radiation monitoring instrument 1 according to one embodiment of the present invention.

[0028] exist Figure 6The portable radiation monitoring instrument 1 shown in the embodiment of this utility model mainly includes a pulsed radiation field detector 10 for detecting pulsed X / γ rays; a continuous radiation field detector 20 for detecting continuous X / γ rays; and a preamplifier 31 and a main amplifier 32 for amplifying the output signals of the pulsed radiation field detector 10 and the continuous radiation field detector 20. Figure 6 (referred to as "preamplifier, main amplifier" in Chinese); a signal processor 40 that processes the signal output from the main amplifier 32; and a display screen 50 for displaying radiation levels. Figure 6 The MCU main control board 60 further processes the signals from the signal processor 40 for display and alarm; the battery 61 serves as the power source for the portable radiation monitor 1. Figure 6 The term "lithium battery" is used in this context; a DC-DC converter 62 converts the direct current from battery 61 to DC power. Figure 6 (abbreviated as "DC-DC" in Chinese); RS485 wired communication module 63; LoRa wireless communication module 64; membrane switch button 65 ( Figure 6 The circuit board described herein is referred to as a "membrane button"; and a GPS / BeiDou positioning module 66. The pulse radiation field detector 10, continuous radiation field detector 20, preamplifier 31 and main amplifier 32, signal processor 40, display screen 50, MCU main control board 60, battery 61, RS485 wired communication module 63, LoRa wireless communication module 64, membrane switch button 65, and GPS / BeiDou positioning module 66 are all mounted on the circuit board of this invention or directly electrically connected to the circuit board.

[0029] For example, the RS485 wired communication module 63 and the LoRa wireless communication module 64 can be omitted if communication with external devices is not required. The GPS / BeiDou positioning module 66 can be omitted if positioning is not required. Components such as the battery 61, display screen 50, and membrane switch button 65 can also be replaced with other corresponding components, which is obvious to those skilled in the art.

[0030] With the above structure, the portable radiation monitor 1 can achieve continuous, short-time and pulsed radiation measurements.

[0031] In order to effectively shield electric or electromagnetic interference, the present invention has made the following structural improvements to the portable radiation monitoring instrument 1 described above.

[0032] The portable radiation monitor 1 of this invention uses a high-strength aluminum alloy with a thickness of 3mm to 6mm as the outer shell material, and undergoes conductive oxidation treatment. The outer surface of the shell is uniformly sprayed with an insulating varnish with a thickness of 50μm to 100μm. As a result, the electric field inside the shell is significantly reduced, effectively shielding against electric or electromagnetic interference.

[0033] The portable radiation monitoring instrument 1 of this utility model has a cuboid structure, and its main structural components include a front cover 101, a rear shell 102, and a battery cover 103 (see reference). Figure 1 , Figure 3 External interfaces are uniformly arranged on the upper left side of the rear shell. All gaps and openings on the outer shell 100 are minimized, and conductive adhesive is used to seal openings and shielding gaps to prevent the presence of suspended metal parts and ensure effective grounding of any suspended metal parts. Openings and shielding gaps sealed with conductive adhesive include at least the battery cover 103, display screen 50, SMA antenna opening 104, and aviation plug opening 105 (see reference). Figure 1 , Figure 3 The location of the SMA antenna opening 104 is for mounting the SMA antenna, and the aviation plug opening 105 is for mounting the aviation plug. Both the SMA antenna opening 104 and the aviation plug opening 105 are equipped with metal sealing caps. The battery 61 is housed in a battery compartment made of conductive material, and the battery cover, also made of conductive material, is tightly fitted to the outer casing.

[0034] The portable radiation monitor 1 of this invention employs a partial shielding scheme for its internal circuit board assembly (PCBA). Specifically, sensitive circuit units within the outer casing are protected with additional shielding covers. These shielding covers are formed by bending and stamping aluminum plates, resulting in a seamless structure. The device's display screen uses a transparent metal film made of transparent metal shielding material, effectively resisting electromagnetic shielding while ensuring high-definition display quality. Figure 5 As shown, the pulse radiation field detector 10 and the continuous radiation field detector 20 are placed in separate mounting slots and encapsulated with aluminum foil material of, for example, 0.03 mm, to effectively resist electromagnetic interference and ensure the accuracy and reliability of pulse radiation field measurement.

[0035] In the portable radiation monitor 1 of this invention, grounding is the most effective method to suppress interference. Therefore, an external ground wire consisting of a grounding point and a grounding wire is provided on the outside of the housing 100; a digital ground wire is provided in the digital circuit section of the circuit board; and an analog ground wire is provided in the analog circuit section of the circuit board. Furthermore, the digital ground wire and the analog ground wire are single-point grounded, connected at a single point using a ferrite bead. The voltage at two points on the power ground wire is a very serious interference to the signal level; therefore, the power ground wire cannot be used as a signal ground wire. Decoupling capacitors are added to reduce power supply common impedance coupling interference between power-consuming units on the same power line. Each unit on the signal ground wire uses single-point grounding, and the connection between the device signal ground wire and the system signal ground wire must not disrupt the system's single-point grounding. The safety ground wire uses single-point grounding and auxiliary grounding to maintain its electrical continuity; during normal operation, no current flows through the safety ground wire.

[0036] Through effective grounding design, the insulation resistance between various ground wires inside the equipment is guaranteed to be greater than 20MΩ, and the insulation resistance between the ground wires and the casing is greater than 100MΩ.

[0037] In the portable radiation monitor 1 of this utility model, component selection is the foundation of circuit assembly shielding design, with priority given to components that can reduce noise and suppress electromagnetic interference. The selection is guided by studying the EMC characteristics of basic circuit components such as capacitors, resistors, magnetic components, relays, various switches, connectors, cables, and analog and logic active devices. Electromagnetic interference generated in the circuit is reduced through the design of power supply decoupling and amplifier decoupling circuits; electromagnetic interference is suppressed by utilizing the balance principle through special circuit design; and the signal-to-noise ratio of signal transmission is improved through the design of special noise suppression circuits.

[0038] Enclosing equipment and peripheral cables with conductive surfaces reduces digital circuit noise and radiation, thus reducing radiation from the PCB source and RF radiation from the PCB. Minimize wiring inductance and establish a good ground bypass filter shield. Depending on design requirements, use methods such as floating I / O cables, single-point grounding, multi-point grounding, and hybrid grounding. Device clocks are a significant radiation source; row drivers and bus drivers often carry large currents. Strictly control the loop area of ​​address buses, data buses, and other signal lines to further reduce PCB radiation. For transient power currents required by logic control circuits, implement decoupling measures, employ common-mode current bypass, shield cables, and provide high common-mode impedance in series with the cables to suppress common-mode interference.

[0039] Example

[0040] Reference Figures 1-5 This invention describes specific embodiments of the portable radiation monitoring instrument 1.

[0041] The portable radiation monitor 1 of this embodiment, which has a preferred electromagnetic shielding structure for improving the accuracy, reliability and anti-interference of equipment radiation measurement, will be described in four aspects below.

[0042] 1. Shell material

[0043] like Figure 1 As shown, the outer shell 100 of the portable radiation monitor 1 in this embodiment is made of 7075-T651 aluminum alloy with a thickness of 5mm, which is a high-strength aluminum alloy and is subjected to conductive oxidation treatment. The outer surface of the shell is uniformly sprayed with an insulating varnish with a thickness of 85μm (50μm to 100μm is acceptable). As a result, the electric field inside the shell is greatly reduced, effectively shielding against electric or electromagnetic interference.

[0044] 2. Structural Design

[0045] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5 As shown, the portable radiation monitor 1 in this embodiment has a cuboid structure. The main structural components include a front cover 101, a rear shell 102, and a battery cover 103. External interfaces are uniformly arranged on the upper left side of the rear shell (see reference). Figure 1 , Figure 2 There are five openings on the outer casing 100, namely:

[0046] (1) Figure 1 and Figure 4 The opening of the display screen 50 shown is covered by a transparent metal film, which is tightly attached to the inside of the outer casing 100 and sealed with conductive adhesive. An additional 5mm thick aluminum alloy shielding cover is added to the inside of the display screen 50 for a second layer of protection.

[0047] (2) Figure 1 , Figure 3 The two SMA (Sub Miniature version A) antenna openings 104 and one aviation plug opening 105 shown are all metal components. They are assembled in the housing 100 using an internal welding process to weld the connectors to the housing 100. Each of them is equipped with a metal sealing cap. When the response function is not working, assembling the shielding cap can better ensure the shielding performance.

[0048] (3) Figure 3The battery cover 103, made of metal, has the same material and thickness as the outer casing 100 and is fitted with it in a trapezoidal structure. The battery cover 103 is made of aluminum, with a wall thickness of 2mm and a bottom thickness of 3mm. The bottom thickness is the same as that of the aforementioned outer casing. The battery cover 103 is tightly fitted to the outer casing 100, and the internal battery compartment provides an additional layer of shielding for the internal circuitry. The electrodes of the battery compartment are soldered to the board to achieve a completely sealed effect.

[0049] The portable radiation monitor 1 in this embodiment employs a partial shielding scheme for its internal circuit board (PCBA). Specifically, sensitive circuit units inside the casing are protected with additional shielding covers. These shielding covers are formed by bending and stamping aluminum plates, resulting in a seamless structure. The display screen 50 uses a transparent metal shielding material, effectively shielding electromagnetic fields while ensuring high-definition display quality. Figure 5 As shown, the pulsed radiation field detector 10 and the continuous radiation field detector 20 are placed in separate mounting slots and encapsulated with aluminum foil material of, for example, 0.03 mm, to effectively resist electromagnetic interference and ensure the accuracy and reliability of pulsed radiation field measurement.

[0050] 3. Grounding Design

[0051] In the portable radiation monitor 1 of this embodiment, grounding is the most effective method to suppress interference. The voltage at two points on the power ground line is a very serious interference to the signal level; therefore, the power ground line cannot be used as the signal ground line. Decoupling capacitors are added to reduce power supply common impedance coupling interference between power-consuming units on the same power line. Each unit on the signal ground line uses single-point grounding, and the connection between the device signal ground line and the system signal ground line must not disrupt the system's single-point grounding.

[0052] To better achieve isolation and ensure stable operation, this system is divided into three locations.

[0053] (1) External ground PGND, PGND is isolated from internal ground, PGND is connected to the housing, and the housing 100 is equipped with a grounding point and grounding wire.

[0054] (2) Digital ground GND: GND provides a reference point for the digital circuit-related parts, mainly including MCU control circuit, LCD display circuit, wired and wireless communication circuit, key interaction circuit, and Beidou positioning circuit.

[0055] (3) Analog ground AGND. AGND provides a reference point for the analog circuit-related parts, mainly including the detector working circuit, the signal processing analog front-end circuit, and the signal shaping and amplification circuit.

[0056] The analog ground and digital ground use single-point grounding, and the single-point connection uses a ferrite bead, which can suppress high-frequency interference between the two ground planes while ensuring the equipotential of the two ground planes.

[0057] 4. PCBA Design

[0058] In the portable radiation monitor 1 of this embodiment, the circuit board (PCBA) is designed with a 6-layer topology, with the top and bottom layers being ground layers and the inner 4 layers serving as signal layers. This effectively suppresses interference and crosstalk of spatial radiation on signal lines.

[0059] The portable radiation monitor 1 comprises four circuit units: a main controller processing unit, a display unit, a positioning and communication unit, and a detector signal processing unit, which includes a preamplifier 31, a main amplifier 32, and a signal processor 40, all mounted on a circuit board. The four modules are arranged separately, with the detector signal processing unit shielded and isolated from the other units, thus protecting areas more susceptible to interference.

[0060] In terms of component selection, the priority is given to components that can reduce noise and suppress electromagnetic interference. Capacitors and inductors are Emc (electromagnetic compatibility) suppression devices manufactured by TDK. The power supply chip uses an LDO (low dropout linear regulator) chip manufactured by Analog Devices (ADI) with a high common-mode power rejection ratio. No switching power supply chips are used, which ensures low power supply noise and avoids space and board-level crosstalk and harmonic interference caused by switching power supplies. A low-frequency main control chip is selected while ensuring performance.

[0061] From the perspective of PCB component layout and routing, inductive components should have a good grounding and discharge path reserved; capacitive components with high and low capacitance values ​​can provide a discharge loop for noise across the entire frequency band; in terms of routing: the bends of copper film lines should be rounded or beveled, and the traces of adjacent layers should be perpendicular, oblique, or curved to avoid parallel traces, reduce parasitic coupling, and the ground line should be thickened so that it can carry three times the allowable current on the printed circuit board and grounded nearby to avoid forming a ground loop.

[0062] With the above structure, the portable radiation monitoring instrument of this invention can effectively shield against electric field, magnetic field or electromagnetic field interference.

[0063] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0064] The technical solutions and technical details disclosed in the embodiments of this utility model are merely illustrative of the utility model concept and do not constitute a limitation on the technical solutions of this utility model. Any conventional changes, substitutions or combinations made to the technical details disclosed in the embodiments of this utility model have the same utility model concept and are within the scope of protection of the claims of this utility model.

Claims

1. A portable radiation monitor, characterized by, It comprises: a shell and a radiation detector, a circuit board, a display screen and a battery arranged in the shell, wherein the shell is made of an aluminum alloy plate with a thickness of 3-6 mm and is subjected to conductive oxidation treatment, the radiation detector is packaged with a metal shielding sheet, the surface of the display screen is provided with a transparent metal film, the battery is arranged in a battery compartment made of conductive material, and a battery cover made of conductive material is tightly assembled with the shell.

2. The portable radiation monitor according to claim 1, characterized in that: SMA antenna openings for mounting SMA antennas and aviation plug openings for mounting aviation plugs are arranged on the shell, the SMA antenna openings and the aviation plug openings are each provided with a metal sealing cap.

3. The portable radiation monitor according to claim 2, characterized in that: conductive glue for sealing is arranged at positions of the shell where the battery cover, the display screen, the SMA antenna openings and the aviation plug openings are arranged.

4. The portable radiation monitor according to claim 1, characterized in that: a shielding cover made of an aluminum plate is arranged on the circuit board.

5. The portable radiation monitor according to claim 1, characterized in that: an external ground wire composed of a grounding point and a grounding line is arranged outside the shell, a digital ground wire is arranged at a digital circuit part of the circuit board, an analog ground wire is arranged at an analog circuit part of the circuit board.

6. The portable radiation monitor according to claim 5, characterized in that: the digital ground wire and the analog ground wire are single-point grounded, and a magnetic bead is used for single-point connection.

7. The portable radiation monitor according to claim 1, characterized in that: the circuit board has a 6-layer board topology structure, wherein the top layer and the bottom layer are ground layers, and the middle 4 layers are signal layers.

8. The portable radiation monitor according to claim 1, characterized in that: the circuit board comprises a main controller processing unit, a detector signal processing unit, a display unit and a positioning communication unit, each unit is arranged separately and shielded and isolated from each other.

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