Method, system and apparatus for providing electronic signal for monitoring and testing geiger-muller radiation sensors

Abstract

To allow for detecting a response of a radiation sensor to a test signal to determine whether the radiation sensor is operating correctly or not.SOLUTION: A method, system and / or apparatus for remotely monitoring the operation of a radiation sensor is provided, the apparatus comprising: a radiation sensor 110 configured to detect the presence of radiation in an area, the radiation sensor including a Geiger-Muller tube; a test signal generator configured to generate a high frequency test signal to be transmitted to the radiation sensor 110 to test the radiation sensor 110; and a test signal detector configured to detect a response of the radiation sensor to the test signal and determine whether the radiation sensor is operating correctly or not.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to methods, systems and / or apparatus for providing electronic signals for monitoring and / or testing of Geiger-Müller tube-based radiation sensors. [Background technology]

[0002] Government regulations for commercial nuclear power plants require regular monitoring of safety devices installed at or located within a nuclear power plant to ensure that the safety devices are functioning properly. The safety devices that must be monitored may include sensors for detecting radiation, such as Geiger-Muller (GM) tube-based sensors.

[0003] Existing radiation sensors that use GM tubes do not allow for indirect and / or remote testing and / or performance testing of the GM tubes. Instead, GM tube-based sensors must be manually inspected by personnel by placing a radiation source near the GM tube and analyzing the GM tube-based sensor's response to the radiation source. This testing method may be undesirable because it exposes personnel to unnecessary radiation. Furthermore, GM tube-based radiation sensors may be permanently or otherwise located in locations that are physically inaccessible, inconvenient, and / or physically hazardous, such as radioactive seam lines within nuclear power plants. In these types of situations, accessing the radiation sensor to test it may be difficult and / or inconvenient. Also, traditional testing methods may require additional personnel to complete testing because the radiation sensor's radiation monitor (e.g., a display panel) may be located in the control facility but not at the radiation sensor's location. Therefore, two or more employees may be required to test a single radiation sensor, which may increase testing costs and reduce employee productivity. Furthermore, because radiation sensor monitoring is performed manually, radiation sensor testing may only be performed periodically, rather than continuously. Periodic testing of radiation sensors alone may not immediately detect malfunctioning radiation sensors, and therefore it may take time to repair and / or replace malfunctioning radiation sensors. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] U.S. Patent Application Publication No. 2010 / 051818 A1 Summary of the Invention

[0005] At least one exemplary embodiment relates to a system for remotely monitoring the operation of a radiation sensor.

[0006] In at least one exemplary embodiment, a system for remotely monitoring the operation of a radiation sensor may include a radiation sensor configured to detect the presence of radiation in an area and including a Geiger-Müller tube, a test signal generator configured to generate a radio frequency test signal used to test the radiation sensor and transmitted to the radiation sensor, and a test signal detector configured to detect a response of the radiation sensor to the test signal and determine whether the radiation sensor is operating properly.

[0007] In some exemplary embodiments, the test signal detector may be configured to output an operational signal indicating that the radiation sensor is operating correctly if the response of the radiation sensor corresponds to the amplitude and frequency of the high frequency test signal.

[0008] In some exemplary embodiments, the test signal detector may be configured to output an operational signal indicating that the radiation sensor is malfunctioning if the response of the radiation sensor does not correspond to the amplitude and frequency of the high frequency test signal.

[0009] In some exemplary embodiments, the test signal detector may be configured to output an operational signal indicating that the Geiger-Müller tube is leaking gas when the amplitude of the response of the radiation sensor is lower than the amplitude of the high frequency test signal.

[0010] In some exemplary embodiments, the test signal detector may be configured to output an operating signal indicating that the anode or cathode of the Geiger-Müller tube is damaged if the amplitude of the response of the radiation sensor is higher or lower than the amplitude of the high frequency test signal.

[0011] In some exemplary embodiments, the test signal detector may be configured to output an operational signal if it does not detect a response from the radiation sensor, indicating that damage to the system's electrical wiring has occurred.

[0012] In some exemplary embodiments, the frequency of the high frequency test signal may be 20 KHz or greater.

[0013] In some exemplary embodiments, the test signal generator and the test signal detector may be connected to the radiation sensor.

[0014] In some exemplary embodiments, the test signal generator and the test signal detector may be connected to a supervisory monitor that includes a display.

[0015] At least one exemplary embodiment relates to a method for remotely monitoring the operation of a radiation sensor.

[0016] In at least one exemplary embodiment, a method for remotely monitoring operation of a radiation sensor may include generating a radio frequency test signal to test a radiation sensor configured to detect the presence of radiation and including a Geiger-Müller tube, transmitting the radio frequency test signal, detecting a response of the radiation sensor to the test signal, and determining whether the radiation sensor is operating properly based on the response of the radiation sensor to the test signal.

[0017] In some exemplary embodiments, if the response of the radiation sensor corresponds to the amplitude and frequency of the high frequency test signal, an operational signal may be output indicating that the radiation sensor is operating properly.

[0018] In some exemplary embodiments, if the response of the radiation sensor does not correspond to the amplitude and frequency of the high frequency test signal, an operational signal may be output indicating that the radiation sensor is malfunctioning.

[0019] In some exemplary embodiments, if the amplitude of the response of the radiation sensor is lower than the amplitude of the high frequency test signal, an operational signal may be output indicating that the Geiger-Müller tube is leaking gas.

[0020] In some exemplary embodiments, if the amplitude of the response of the radiation sensor is higher or lower than the amplitude of the high frequency test signal, an operating signal may be output indicating that the anode or cathode of the Geiger-Müller tube is damaged.

[0021] In some exemplary embodiments, if the test signal detector does not detect a response from the radiation sensor, it may output an operational signal indicating that damage to the system's electrical wiring has occurred.

[0022] In some exemplary embodiments, the generating may include the high frequency test signal having a frequency of 20 KHz or greater.

[0023] At least one exemplary embodiment relates to an apparatus for monitoring the operation of a radiation sensor.

[0024] In at least one exemplary embodiment, an apparatus for monitoring operation of a radiation sensor may include a test signal generator configured to generate a high frequency test signal used to test the radiation sensor and transmitted to the radiation sensor, and a test signal detector configured to detect a response of the radiation sensor to the test signal and determine whether the radiation sensor is operating correctly.

[0025] In some exemplary embodiments, the apparatus may include a first cable connecting a test signal generator and a test signal detector to a radiation sensor including a Geiger-Müller tube, and a second cable connecting the test signal generator and the test signal detector to a surveillance monitor including a display, and a high frequency test signal may be transmitted from the test signal generator to the radiation sensor via the first cable.

[0026] In some exemplary embodiments, the test signal generator and test signal detector may be attached to an surveillance monitor.

[0027] In some exemplary embodiments, the test signal generator and the test signal detector may be attached to the radiation sensor.

[0028] Various features and advantages of the non-limiting exemplary embodiments herein will become more apparent from a consideration of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for illustrative purposes only and should not be construed as limiting the scope of the claims. The accompanying drawings are not to be considered as drawn to scale unless expressly stated otherwise. Various dimensions of the drawings may be exaggerated for clarity. [Brief explanation of the drawings]

[0029] [Figure 1] FIG. 1 illustrates a system for remotely monitoring the operation of a radiation sensor in accordance with an exemplary embodiment. [Figure 2] 2 illustrates components of an apparatus for remotely monitoring the operation of a radiation sensor that may be used by the system of FIG. 1 in accordance with an exemplary embodiment. [Figure 3] FIG. 10 illustrates a routine for remotely monitoring the operation of a radiation sensor, according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0030] Various exemplary embodiments will now be described more fully hereinafter with reference to the accompanying drawings, in which several exemplary embodiments are shown.

[0031] Detailed exemplary embodiments are disclosed herein. However, the specific structural and functional details disclosed herein are merely exemplary for purposes of describing exemplary embodiments. However, the embodiments may be embodied in many alternative forms and should not be construed as being limited to only the exemplary embodiments described herein.

[0032] Although terms such as first, second, etc. may be used herein to describe various elements, it will be understood that these elements should not be limited by these terms. These terms are merely used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of exemplary embodiments of the present invention. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0033] When an element is referred to as being "connected" or "coupled" to another element, it will be understood that it may be directly connected or coupled to the other element, or that intervening elements may be present. Conversely, when an element is referred to as being "directly connected" or "directly coupled" to another element, there may not be intervening elements. Other words used to describe relationships between elements should be construed in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.).

[0034] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless expressly stated otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or sets thereof.

[0035] It should also be noted that in some alternative implementations, the functions / acts described may occur out of the order noted in the figures. For example, two figures shown in succession may in fact be executed substantially concurrently or may sometimes be executed in the reverse order, depending on the functions / acts involved.

[0036] Specific details are provided in the following description to provide a thorough understanding of the exemplary embodiments. However, it will be understood by those skilled in the art that the exemplary embodiments may be practiced without these specific details. For example, systems may be shown in block diagrams in order to avoid obscuring the exemplary embodiments in unnecessary detail. In other instances, well-known processes, structures, and techniques may be shown without unnecessary detail in order to avoid obscuring the exemplary embodiments.

[0037] Also, it should be noted that the exemplary embodiments may be described as a process that is depicted as a flowchart, a flow diagram, a data flow diagram, a structure diagram, or a block diagram. While a flowchart may describe operations as a sequential process, many of the operations can be performed in parallel, simultaneously, or concurrently. Additionally, the order of operations may be rearranged. A process may terminate when its operations are completed, but may have additional steps not included in the diagram. A process may correspond to a method, a function, a procedure, a subroutine, a subprogram, etc. When a process corresponds to a function, its termination may correspond to a return of the function to the calling function or the main function.

[0038] Furthermore, as disclosed herein, the term "memory" can refer to one or more devices for storing data, including random access memory (RAM), magnetic RAM, core memory, and / or other machine-readable media for storing information. The term "storage medium" can refer to one or more devices for storing data, including read-only memory (ROM), random access memory (RAM), magnetic RAM, core memory, magnetic disk storage media, optical storage media, flash memory devices, and / or other machine-readable media for storing information. The term "computer-readable medium" may include, but is not limited to, portable or fixed storage devices, optical storage devices, wireless channels, and various other media capable of storing, containing, or carrying instruction(s) and / or data.

[0039] Furthermore, the exemplary embodiments may be implemented by hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof. If implemented by software, firmware, middleware, or microcode, the program code or code segments to perform the necessary tasks may be stored in a machine- or computer-readable medium such as a storage medium. A processor(s) may perform the necessary tasks.

[0040] A code segment may represent a procedure, a function, a subprogram, a program, a routine, a subroutine, a module, a software package, a class, or any combination of instructions, data structures, or program statements. A code segment can be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. may be passed, forwarded, or transmitted via any suitable techniques including memory sharing, message passing, token passing, network transmission, etc.

[0041] The exemplary embodiments are described as being implemented in a suitable computing environment. Although not required, the exemplary embodiments are described in the general context of computer-executable instructions, such as program modules or functional processes, being executed by one or more computer processors or CPUs. Generally, program modules or functional processes include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular data types. The program modules and functional processes described herein can be implemented using existing hardware in existing communication networks. For example, the program modules and functional processes described herein can be implemented using existing hardware in existing network elements or control nodes. Such existing hardware can include one or more digital signal processors (DSPs), application-specific integrated circuits, field-programmable gate array (FPGA) computers, etc.

[0042] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments belong. Terms, including terms defined in commonly used dictionaries, should be interpreted to have a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an idealized or overly formal sense unless specifically defined herein.

[0043] 1 illustrates a system for remotely monitoring the operation of a radiation sensor, according to an exemplary embodiment. The radiation sensor remote monitoring system 100 can include a radiation sensor 110 including a GM tube 115, a GM tube monitoring device 120, an eye monitor 130, and signal cables 140 and 150.

[0044] According to various exemplary embodiments, the GM tube 115 may be used with, integrated into, or connected to a radiation sensor. The GM tube 115 may include an enclosure that can be filled with a gas mixture, which may be at a pressure lower than atmospheric pressure. The gas mixture may include a "counting" gas, such as argon, and a "quenching" gas, such as bromine or other halogen gas. The GM tube enclosure may be made of a conductive material, such as stainless steel, or may include any material whose interior surface is coated with a conductive material. The conductive material of the enclosure and / or the enclosure itself can act as a cathode electrode. The enclosure may be hollow and thin-walled, which can be sealed and insulated from a small-diameter current-collecting center conductor wire, which can act as an anode electrode. The current-collecting center conductor wire can be made of a conductive material, such as stainless steel. The current-collecting center conductor wire may be coaxially disposed inside the cathode electrode. The GM tube 115 may additionally include glass insulators at both ends of the cylindrical enclosure.

[0045] In various embodiments, a high voltage potential can be applied between the cathode and anode electrodes to generate a strong electric field within the GM tube 115. When ionizing radiation strikes the GM tube 115, i.e., when radioactive particles from a radiation source enter the GM tube 115 enclosure, certain molecules in the gas mixture within the enclosure can be directly ionized by the incident radiation, creating positively charged "ion pairs." This is called a primary ionization event. Furthermore, an avalanche of secondary ion pairs can be generated when the positively charged ion pairs from the primary ionization event are accelerated by the strong electric field within the enclosure toward the negatively charged anode, and the movement of the ion pairs from the primary ionization event ionizes additional gas molecules within the entire volume of the enclosure. The ionic charges of the collected ion pairs can generate an output electrical pulse. Therefore, the GM tube 115 can output an electrical pulse of several volts or more with a uniform amplitude, regardless of the number of ion pairs formed in the detector by the radiation causing the primary ionization event.

[0046] During an ionization event, collisions occur between counting gas molecules and quenching gas molecules in the gas mixture of the GM tube 115. The collisions transfer positive charge from the counting gas molecules to the quenching gas molecules. As a result, all positive ions that ultimately reach the cathode electrode become quenching gas molecules due to positive charge transfer collisions. When the positively charged quenching gas molecules reach the cathode electrode, they are neutralized by electrons from the cathode. The excess energy of the electrons after neutralizing the charge of the quenching gas molecules is dissipated by dissociating more complex quenching gas molecules in preference to liberating free electrons from the surface of the cathode. Consequently, the discharge in the GM tube is completed because the frequency of dissociation of quenching gas molecules is much greater than the generation of electron emissions to initiate further ionization. After an ionization event, i.e., after radiation detection, dissociation of the quench gas molecules occurs, causing the GM tube 115 to lose quench gas, which limits the "counting" life of the GM tube 115. Commercially available GM tubes typically have a lifespan of 10-15 years.

[0047] In addition to the gradual weakening and eventual failure of the GM tube 115 due to dissociation of the quench gas molecules, the GM tube can fail, malfunction, and / or malfunction due to other factors, such as leakage of the gas mixture from the sealed GM tube enclosure, or loss of passivation of the GM cathode.

[0048] For example, the GM tube 115 may be subjected to mechanical stress during the manufacture of the GM tube and / or during the manufacture of a GM tube-based radiation sensor. Mechanical stress on the GM tube can cause microcracks to form in the glass-to-metal seals at either end of the GM tube 115. Microcracks in the glass-to-metal seals can cause the counting and quenching gases to leak very slowly within the GM tube enclosure, potentially introducing foreign gas molecules (e.g., air) into the enclosure volume. The very slow loss of the counting and quenching gases from the GM tube enclosure volume temporarily establishes conditions within the GM tube that significantly increase the length of "dead time," ultimately leading to complete failure of the GM tube and / or radiation sensor. Furthermore, a significant increase in dead time can mask some of the closely spaced ionization events that occur at high radiation levels, causing the GM tube to respond nonlinearly.

[0049] Dead time is a term used to describe the interval between the initiation of an ionization event that develops into an avalanche discharge and the time during which the ionization in the GM tube has dissipated enough to restore the electric field within the GM tube for a subsequent ionization event that will trigger the next normal-magnitude avalanche discharge. If a subsequent ionization event occurs during the dead time of a previous ionization event, i.e., if another radioactive particle strikes the GM tube during the dead time, the electric field will not fully recover, and the resulting discharge will be less intense than the original discharge. As a result, the amplitude of the output pulse from the subsequent ionization event during the dead time is reduced because fewer positive ions are required to terminate the discharge by transferring positive charge from the counting gas molecules to the quenching gas molecules. The output electrical pulse generated during the dead time by the subsequent ionization event has a smaller amplitude than the original output electrical pulse and may not be large enough to pass the detection threshold level used by conventional radiation sensors to filter out false positive signatures from actual radiation detection signatures.

[0050] More importantly, the failure mode of GM tubes resulting in a longer measurable dead time exhibits near-normal behavior for low levels of radiation from radioactive test sources commonly used in manual radiation sensor testing. Radiation from the test source can cause very low radiation count rates due to the statistical probability of infrequent and very few ionization events occurring during the longer measurable dead time due to microcracks, leaks, and / or reduction in counting and quenching gas from the GM tube. Essentially, all of the output pulses generated by a low-level test source exceed the detection threshold level, preventing a malfunction of the GM tube / radiation sensor from being observed. However, if there is a radiation source containing higher radiation levels around the malfunctioning GM tube / radiation sensor, the higher radiation levels are statistically much more likely to produce more ionization events during the longer dead time interval. Because a significant portion of the additional ionization events occur during the longer dead time period, the radiation sensor continues to generate output pulses with amplitudes below the detection threshold level, and higher radiation levels can produce a false indication that the response is lower than the actual radiation level.

[0051] Another example of a GM tube failure mode is the loss of passivation of the GM cathode during construction, production, and / or manufacturing. Prior to construction of a GM tube, the inside of the hollow, thin-walled, stainless steel cylindrical cathode is chemically passivated by generating chromium oxide, which forms a thin protective film on the inner surface of the cathode electrode. The formation of the protective film on the inner surface prevents further chemical reactions between the enclosure and the gas mixture that fills it. Unprotected metal surfaces are highly sensitive to halogen ions formed during ionization events, and if left unprotected, they can cause chemical reactions that form halogen-metal compounds on the interior surface of the metal enclosure. Passivating the inner surface of the GM tube metal cathode is another important technique for preventing the loss of halogen quench gas inside the GM tube. Loss of halogen quench gas also measurably increases the length of dead time within the GM tube, shielding dense ionization events that occur during the dead time, thereby causing the GM tube to respond nonlinearly to high radiation levels, as detailed above.

[0052] As part of the GM tube production process, high-temperature molten glass is placed on both ends of a thin-walled metal cylindrical cathode, allowing it to cool during production. This step is performed to seal the gas mixture within the GM tube volume and insulate the wire anode, which is placed coaxially inside the cathode. Applying heat to a GM tube in this manner can degrade the passive protective film on the inner surface of the cylindrical cathode. Loss of the passive protective film makes valence electrons on the exposed metal surface available for chemical reaction with other elements exposed to the metal surface. Cathodes that are exposed to excessive heat, or for extended periods of time when molten glass is placed on both ends of the cathode during production, can degrade and / or partially destroy the passive protective film, leaving the cathode's inner metal surface unprotected. The unprotected inner metal surface of the cathode chemically reacts with halide ions, gradually depleting the quench gas from the GM tube enclosure volume. Ultimately, the gradual depletion of quench gas initiates a dead time that increases in length, leading to an increase in the dead time period. As a result, loss of some of the quench gas causes the GM tube to provide a nearly normal (i.e., appropriate and / or expected) detection response to low radiation levels, but causes the GM tube to respond nonlinearly at higher radiation levels.

[0053] Another challenge faced when attempting to detect loss of GM cathode passivation is the problem of ensuring that GM tubes that experience degradation and / or partial destruction of the passive protective coating respond correctly immediately after manufacture. It can take a relatively long time, e.g., a year or more, before enough halide quench gas ions chemically react with the internal metal cylindrical cathode to sufficiently deplete the halide quench gas and measurably increase the length of the GM tube's dead-time period. Thus, a GM tube-based radiation sensor may appear to be in proper operating condition when first installed or manufactured, but may actually have entered a failure mode that does not significantly increase the length of dead-time by several months after installation or after being stored as a spare part.

[0054] Referring again to FIG. 1 , the system for remotely monitoring the operation of radiation sensor 110 can further include GM tube monitoring device 120. GM tube monitoring device 120, which will be described in further detail in connection with FIG. 2 , can be connected to one or more GM tubes and / or radiation sensors via signal cable 140. GM tube monitoring device 120 can also be connected to monitoring monitor 130 and / or radiation monitor (not shown) via second signal cable 150. The signal cable may be a coaxial cable, a data cable, a twisted pair cable, an optical fiber cable, or the like. Monitoring device 120 can transmit signals to radiation sensor 110 and, in response to the transmitted signals, can receive signals that can be used to determine the operational status of radiation sensor 110 and / or GM tube 115. When a response signal from radiation sensor 110 is received by monitoring device 120, the monitoring device can analyze the response signal and determine the current operational status of radiation sensor 110 and / or GM tube 115 (i.e., determine whether the GM tube and radiation sensor are operating correctly or determine a failure mode of the GM tube or radiation sensor). After determining the current operating status of the radiation sensor 110 and / or GM tube 115, the monitoring device 120 can then transmit the operating status and / or failure mode data via signal cable 150 to the monitoring monitor 130 and / or computing system (not shown) for display and further action.

[0055] Additionally, in various exemplary embodiments, monitoring device 120 may include a physical computer hardware device capable of communicating with one or more other hardware computing devices (e.g., surveillance monitor 130 and / or GM tube 115) via a communications interface. Monitoring device 120 may also communicate wirelessly via a transmitter and receiver (or optionally a transceiver) and / or using a communications port. The monitoring device 120 may also include a network interface configured to connect the monitoring device to one or more other hardware computing devices (e.g., computing systems such as servers, workstations, laptops, smartphones, tablets, etc.) via a wired connection using a wireless connection. The monitoring device 120 may be configured to send and receive data to and from one or more other hardware computing devices and / or network devices, such as routers, switches, or other similar network devices, via the network interface using a wired and / or wireless connection. The wireless transmitter / receiver and / or transceiver may be configured to operate in accordance with the IEEE 802.11-2007 standard (802.11), the Bluetooth standard, and / or any other similar wireless standard. The communication port may be configured to operate in accordance with a wired communication protocol, such as a serial communication protocol (e.g., Universal Serial Bus (USB), Firewire, Serial Digital Interface (SDI), and / or other similar serial communication protocol), a parallel communication protocol (e.g., IEEE 1284, Computer Automated Measurement And Control (CAMAC), and / or other similar parallel communication protocol), and / or a network communication protocol (e.g., Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), and / or other similar network communication protocol). The monitoring device 120 may be configured to transmit or communicate generated monitoring data corresponding to operation of the radiation sensor 110 and / or the GM tube 115 to one or more other hardware computing devices via the network interface.

[0056] In various exemplary embodiments, the system for remotely monitoring the operation of radiation sensor 110 may include surveillance monitor 130. Surveillance monitor 130 may also include a display 133 that may be configured to at least display information regarding results of the monitoring of one or more radiation sensors received from surveillance monitor 130. Surveillance monitor 130 may also include user input controls 134 (e.g., push buttons, keypad, etc.) for controlling surveillance monitor 130, monitoring device 120, and / or radiation sensor 110.

[0057] The monitor 130 may also include a radiation monitor (not shown) capable of analyzing, interpreting, and displaying data related to radiation detected by the GM tube-based radiation sensor. The monitor 130 may include a high-voltage power supply (not shown) and a femtoampere meter (not shown). The high-voltage power supply may be configured to supply a high voltage (e.g., 300-600 VDC) to the GM tube 115, charging the anode electrode of the GM tube 115 and generating a strong electric field within the GM tube enclosure described above. The femtoampere meter may be configured to detect current flow within the closed circuit of the system 100, thereby detecting ionization events detected by the GM tube 115. Alternatively, the radiation monitor may be separate from the monitor 130. The monitor 130 may be attached to the monitoring device 120 and / or the mobile GM tube-based radiation sensor 110. Additionally and / or alternatively, the monitor 130 may be located in a location physically separate from the radiation sensor 110, such as a control room, a command center, etc.

[0058] According to various exemplary embodiments, a computing system (not shown) is a physical hardware computing device that can communicate with one or more other hardware computing devices (e.g., monitoring device 120, surveillance monitor 130, one or more associated databases (not shown), etc.) via a communication interface such that the computing system can receive one or more signals and / or data streams from the other hardware computing devices. The computing system can include memory and one or more processors. The computing system can be designed to sequentially and automatically perform a series of arithmetic or logical operations, can be equipped to record / store data on a machine-readable medium, and can transmit and receive data via one or more network devices. The computing system may include devices such as desktop computers, laptop computers, mobile terminals (e.g., tablet personal computers, etc.), and / or any other physical or logical device that can record, store, and / or transfer digital data via connection to a network device.

[0059] In various exemplary embodiments, the computing system may include a network interface configured to connect the computing system to one or more other hardware computing devices (e.g., monitoring device 120, surveillance monitor 130, one or more associated databases (not shown), etc.) wirelessly via a transmitter and receiver (or optionally a transceiver) and / or via a wired connection using a communication port. The computing system may be configured to send and receive data to and from one or more other hardware computing devices and / or network devices, such as routers, switches, or other similar network devices, via the network interface using wired and / or wireless connections. The wireless transmitter / receiver and / or transceiver may be configured to operate in accordance with the IEEE 802.11-2007 standard (802.11), the Bluetooth standard, and / or any other similar wireless standard. The communications port may be configured to operate in accordance with a wired communications protocol, such as a serial communications protocol (e.g., Universal Serial Bus (USB), Firewire, Serial Digital Interface (SDI), and / or other similar serial communications protocol), a parallel communications protocol (e.g., IEEE 1284, Computer Automated Measurement And Control (CAMAC), and / or other similar parallel communications protocol), and / or a network communications protocol (e.g., Ethernet, Token Ring, Fiber Distributed Data Interface (FDDI), and / or other similar network communications protocol).The computing system may be configured to store information regarding the current status of one or more GM tube-based radiation sensors and may alert personnel to a failure of a GM tube of a radiation sensor, the need for repair and / or replacement of a GM tube of a radiation sensor or a cable connecting the radiation sensor to a radiation monitor and / or surveillance monitor, and / or provide a log of past performance of the radiation sensor, etc.

[0060] As shown in FIG. 1 , there is only one radiation sensor 110, one monitoring device 120, and one monitoring monitor 130. However, according to various exemplary embodiments, any number of radiation sensors, monitoring devices, monitoring monitors, radiation monitors, and / or computing systems may be present. Further, in various exemplary embodiments, radiation sensor 110, monitoring device 120, monitoring monitor 130, radiation monitor, and / or computing system may be wireless network devices. Additionally, or alternatively, in various exemplary embodiments, radiation sensor 110, one monitoring device 120, and one monitoring monitor 130 and / or radiation monitor may be provided as a single device. Furthermore, in various exemplary embodiments, components of radiation sensor 110, monitoring device 120, monitoring monitor 130, and / or radiation monitor may be described and illustrated as being present within radiation sensor 110, monitoring device 120, monitoring monitor 130, and / or radiation monitor, although this is not required and individual configuration elements may be present in one or more of the other components of a system for remotely monitoring the operation of radiation sensor 110. It should be understood that the element may be located and / or included.

[0061] FIG. 2 illustrates components of radiation sensor 110, monitoring device 120, and surveillance monitor 130, according to an example embodiment.

[0062] In various exemplary embodiments, monitoring device 120 may include test signal generator 210, which may be connected to the anode electrode of GM tube 115, and test signal detector 220, which may be connected to the cathode electrode of GM tube 115. Test signal generator 210 may be configured to generate a high-frequency test signal that may be used to test radiation sensor 110. More specifically, test signal generator 210 may generate a high-frequency test signal that is transmitted to the anode electrode of GM tube 115. Test signal generator 210 may be a function generator, and test signal detector 220 may be an oscilloscope. If the GM tube is operating properly, test signal detector 220 detects a test signal at the same or substantially similar frequency as that generated by test signal generator 210. The high-frequency test signal may be continuously generated and transmitted by test signal generator 210 to continuously monitor GM tube 115 and / or radiation sensor 110. Additionally, the high-frequency test signal may be generated and transmitted at regular intervals or as needed to test GM tube 115. To distinguish high frequency test signals from signals generated by a properly functioning GM tube of the radiation sensor during normal operation, which are typically low frequency DC signals, the test signal generator 210 can be configured to generate a test signal at a high frequency that is distinguishable from normal GM tube frequencies. For example, the test signal generator can generate a test signal that can be 20 KHz or higher. The frequency of the test signal generated may depend on the size of the GM tube used in the radiation sensor 110.

[0063] In some exemplary embodiments, test signal detector 220 may be configured to detect and analyze the high-frequency test signal transmitted by test signal generator 210 and transmitted through GM tube 115. As described above, if GM tube 115 is operating correctly, the signal detected by test signal detector 220 will be the same or substantially similar frequency as that generated by test signal generator 210. However, if the GM tube is not operating correctly, the signal detected by test signal detector 220 will have different characteristics from the test signal generated and transmitted by test signal generator 210. For example, if the amplitude of the detected test signal is lower than expected, the electrical characteristics of the GM tube may have changed, indicating that the GM tube is leaking gas. If the amplitude of the detected test signal changes from positive to negative (i.e., the polarity of the test signal is reversed), the electrodes of the GM tube may be damaged. If the radiation sensor 110 and / or the wiring and / or cables of radiation monitoring system 100 are damaged, the test signal detector will not detect the test signal because an open circuit exists in the closed system of radiation monitoring system 100.

[0064] Thus, according to at least one exemplary embodiment, test signal detector 220 determines whether the detected signal is within an acceptable and / or desired range of frequency values ​​and outputs the result of the determination to surveillance monitor 130 and / or a computing system, where the acceptable and / or desired range of frequency values ​​is based on the frequency of the generated test signal. For example, the acceptable range of frequency values ​​may be within a desired deviation (e.g., + / - 10%) of the frequency of the generated test signal. The acceptable and / or desired range of frequency values ​​may be determined according to experimental studies of various available GM tube models or may be configured for a specific GM tube model. The acceptable and / or desired range of frequency values ​​may be expressed as a percentage of deviation or as absolute values ​​of acceptable and / or desired minimum and maximum frequencies. Furthermore, test signal detector 220 may be configured to determine whether the detected signal is above an acceptable and / or desired threshold, where the threshold is determined based on the frequency of the test signal at which the GM tube is detected and the threshold. The threshold value may be set so that test signal detector 220 can determine whether the GM tube is functioning properly based on a comparison with a threshold value. For example, the threshold value may be set to a value of -10% of the frequency of the generated test signal, and if the detected test signal is greater than the threshold value, the test signal detector determines that the GM tube is functioning properly. The acceptable and / or desired threshold value may be a design parameter determined based on experimental studies of various available GM tube models, or may be determined for a particular GM tube model.

[0065] Additionally, the test signal detector 220 may be configured to detect the voltage of the high-frequency test signal to determine whether the GM tube is leaking gas and then output the determination result to the surveillance monitor 130 and / or a computing system. The test signal detector 220 may be configured to detect whether the detected signal is within an acceptable and / or desired range of voltage values, where the acceptable and / or desired range of voltage values ​​is based on the voltage of the generated test signal. For example, the acceptable range of voltage values ​​may be within a desired deviation (e.g., + / - 10%) of the voltage of the generated test signal. The acceptable and / or desired range of voltage values ​​may be determined according to experimental studies of various available GM tube models or may be configured for a specific GM tube model. The acceptable and / or desired range of voltage values ​​may be expressed as a percentage of deviation or as absolute values ​​of the acceptable and / or desired minimum and maximum frequencies. Additionally, test signal detector 220 may be configured to determine whether the detected signal exceeds an acceptable and / or desired threshold voltage value, where the threshold is set to enable test signal detector 220 to determine whether the GM tube is leaking gas based on a comparison of the voltage of the detected test signal with the threshold. For example, the threshold may be set to a value of −10% of the voltage of the generated test signal, and if the detected test signal is greater than the threshold, the test signal detector determines that the GM tube is not leaking gas. The acceptable and / or desired threshold may be a design parameter determined based on experimental studies of various available GM tube models, or may be determined for a particular GM tube model.

[0066] The test signal detector 220 may also be configured to detect whether the electrodes of the GM tube are damaged by comparing the polarity of the detected test signal with the polarity of the generated test signal, and then output the result of the determination to the eye monitor 130 and / or the computing system. For example, if the polarity of the generated test signal is positive and the polarity of the detected test signal is negative, the test signal detector determines that the electrodes of the GM tube are damaged and outputs the result to the eye monitor 130 and / or the computing system.

[0067] The test signal detector 220 may also be configured to detect whether the wiring and / or cables of the radiation sensor 110 and / or the radiation monitoring system 100 are damaged. For example, the test signal detector 220 may be configured to receive an indication that a test of a GM tube has begun, such as an indication that the test signal generator has generated and transmitted a test signal, and may be further configured to determine whether the test signal of the test signal detector is detected within an acceptable and / or desired time after the start of the test. If the test signal is not detected within the acceptable and / or desired time, the test signal detector may be configured to determine that the wiring and / or cables of the radiation sensor 110 and / or the radiation monitoring system 100 are damaged and output the result to the eye monitor 130 and / or the computing system. For example, the acceptable time for detecting the test signal may be set to one second or less. The acceptable and / or desired time may be a design parameter determined based on an experimental study of the electrical characteristics of various available GM tube models, or may be determined for a particular GM tube model.

[0068] The above test signal detector determinations are provided for illustrative purposes only and are not limiting of test signal detector 220. Test signal detector 220 may be configured to monitor and / or test for additional types of failure modes as well.

[0069] Once the test signal detector 220 determines the current operating status and / or type of failure mode of the radiation sensor 110, the test signal detector 220 may output the result of the determination to the eye monitor .

[0070] In various exemplary embodiments, surveillance monitor 130 may include a radiation (or pulse) detector circuit 230 and a high-voltage power supply 240. Radiation detector circuit 230 may be configured to determine the level of radiation detected by GM tube 115, i.e., to "count" radiation, by determining the number of output pulses generated by GM tube 115 following an ionization event. Radiation detector circuit 230 may be configured to count only output pulses having an amplitude greater than a configurable detection threshold level.

[0071] As mentioned above, the supervisory monitor 130 may also include a high voltage power supply 240 that at least partially generates the strong electric field within the GM tube 115 .

[0072] 3 illustrates a routine for remotely monitoring the operation of a radiation sensor, according to an exemplary embodiment. The routine may be used to remotely monitor the operational status of a radiation sensor, such as radiation sensor 110, using monitoring device 120. While the operation of the routine is described as being performed by the systems and apparatus of FIGS. 1-2, it should be noted that any monitoring system may operate the monitoring routine of FIG. 3, as described below.

[0073] 3 , as shown in operation S310, the test signal generator 210 may generate a desired high-frequency test signal. In operation S320, the high-frequency test signal may be transmitted to the radiation sensor 110. In operation S330, the test signal detector 220 may detect a response of the radiation sensor to the test signal. In operation S340, the test signal detector 220 may determine whether the radiation sensor is operating correctly based on the response of the radiation sensor to the test signal.

[0074] As shown in operation S350, the remote monitoring routine ends.

[0075] As will be appreciated, a technical effect of a method, system, and / or apparatus according to exemplary embodiments enables remote monitoring, testing, and / or monitoring of Geiger-Müller tube-based radiation sensors, particularly those located in physically inconvenient and / or inaccessible locations. Various exemplary embodiments may also provide the ability to monitor Geiger-Müller tube-based radiation sensors without exposing personnel to unnecessary radiation doses. Various exemplary embodiments, particularly by using continuous monitoring of Geiger-Müller tube-based radiation sensors, may more quickly detect suboptimal operation and / or failure of the radiation sensor to provide a better mean time to repair (MTTR) for the Geiger-Müller tube-based radiation sensors. Various exemplary embodiments may further provide an inexpensive operation for monitoring Geiger-Müller tube-based radiation sensors.

[0076] It should be noted that although exemplary embodiments may be described in the context of nuclear safety-related systems, exemplary embodiments may also be applied to any industry in which radiation detection sensors and / or Geiger-Müller tubes may be used or required, including nuclear engineering, forensic engineering, mechanical engineering, electrical engineering, civil engineering, systems engineering, aeronautical engineering, nautical engineering, astronautical engineering, medicine, scientific research, and / or any other similar field dealing with the use, design, construction, testing, and / or maintenance of objects related to radioactive materials or sites and / or potentially radioactive materials or sites.

[0077] This specification uses examples of the disclosed subject matter to enable any person skilled in the art to practice the same, including making and using any device or system, and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims. [Explanation of symbols]

[0078] 100 Radiation Sensor Remote Monitoring System 110 Radiation Sensor 115 Geiger-Muller (GM) tube 120 GM tube monitoring device 130 Surveillance Monitor 131 High voltage power supply 132 Femtoampere meter 133 Display 134 User Input Control 140 Signal Cable 150 signal cable 210 Test Signal Generator 220 Test Signal Detector 230 Radiation (pulse) detector circuit 240 High Voltage Power Supply

Claims

1. A system (100) for remotely monitoring the operation of a radiation sensor (110), comprising: a radiation sensor (110) configured to detect the presence of radiation in an area and including a Geiger-Müller tube (115); a test signal generator (210) used to test the radiation sensor (110) and configured to generate a high frequency test signal to be transmitted to the radiation sensor (110); a test signal detector (220) configured to detect a response of the radiation sensor (110) to the test signal and determine whether the radiation sensor (110) is operating properly; A system (100) comprising:

2. 2. The system (100) of claim 1, wherein the test signal detector (220) is configured to output an operational signal indicating that the radiation sensor (110) is operating correctly when the response of the radiation sensor (110) corresponds to the amplitude and frequency of the high-frequency test signal.

3. 2. The system (100) of claim 1, wherein the test signal detector (220) is configured to output an operational signal indicating that the radiation sensor (110) is malfunctioning if the response of the radiation sensor (110) does not correspond to the amplitude and frequency of the high-frequency test signal.

4. 2. The system of claim 1, wherein the test signal detector is configured to output an operational signal indicating that the Geiger-Müller tube is leaking gas when the amplitude of the response of the radiation sensor is lower than the amplitude of the high-frequency test signal.

5. 2. The system of claim 1, wherein the test signal detector is configured to output an operational signal indicating that an anode or cathode of the Geiger-Müller tube is damaged if the amplitude of the response of the radiation sensor is higher or lower than the amplitude of the high-frequency test signal.

6. 2. The system (100) of claim 1, wherein the test signal detector (220) is configured to output an operational signal indicating that damage to electrical wiring of the system (100) has occurred if the test signal detector (220) does not detect a response from the radiation sensor (110).

7. The system (100) of claim 1, wherein the high frequency test signal has a frequency of 20 KHz or greater.

8. The system (100) of claim 1, wherein the test signal generator (210) and the test signal detector (220) are connected to the radiation sensor (110).

9. The system (100) of claim 1, wherein the test signal generator (210) and the test signal detector (220) are connected to a supervisory monitor (130) including a display (133).

10. A method for remotely monitoring the operation of a radiation sensor (110), comprising: generating a radio frequency test signal to test a radiation sensor (110) configured to detect the presence of radiation and including a Geiger-Müller tube (115); transmitting the high frequency test signal; detecting a response of the radiation sensor (110) to the test signal; determining whether the radiation sensor (110) is operating properly based on the response of the radiation sensor (110) to the test signal; A method comprising:

11. If the response of the radiation sensor (110) corresponds to the amplitude and frequency of the high frequency test signal, outputting an operation signal indicating that the radiation sensor (110) is operating properly. The method of claim 10 further comprising:

12. If the response of the radiation sensor (110) does not correspond to the amplitude and frequency of the high frequency test signal, outputting an operating signal indicating that the radiation sensor (110) is malfunctioning. The method of claim 10 further comprising:

13. If the amplitude of the response of the radiation sensor (110) is lower than the amplitude of the high frequency test signal, the Geiger-Müller tube (115) outputs an operating signal indicating a gas leak. The method of claim 10 further comprising:

14. If the amplitude of the response of the radiation sensor (110) is higher or lower than the amplitude of the high frequency test signal, outputting an operating signal indicating that the anode or cathode of the Geiger-Müller tube (115) is damaged. The method of claim 10 further comprising:

15. If the test signal detector (220) does not detect a response from the radiation sensor (110), outputting an operational signal indicating that damage to the electrical wiring of the system (100) has occurred. The method of claim 10 further comprising:

16. The method of claim 10 , wherein the generating step includes the high frequency test signal having a frequency of 20 KHz or greater.

17. 1. An apparatus for monitoring the operation of a radiation sensor (110), comprising: a test signal generator (210) used to test the radiation sensor (110) and configured to generate a high frequency test signal to be transmitted to the radiation sensor (110); a test signal detector (220) configured to detect a response of the radiation sensor (110) to the test signal and determine whether the radiation sensor (110) is operating properly; 1. An apparatus comprising:

18. a first cable connecting the test signal generator (210) and the test signal detector (220) to the radiation sensor (110) including a Geiger-Müller tube; a second cable connecting the test signal generator (210) and the test signal detector (220) to a supervisory monitor (130) including a display (133); Including, 18. The apparatus of claim 17, wherein the high frequency test signal is transmitted from the test signal generator (210) to the radiation sensor (110) via the first cable.

19. 18. The apparatus of claim 17, wherein the test signal generator (210) and the test signal detector (220) are attached to the supervisory monitor (130).

20. The apparatus of claim 17, wherein the test signal generator (210) and the test signal detector (220) are attached to the radiation sensor (110).

Images