An ionization radon detection device and a radon concentration detection method

Abstract

The application provides an ionization radon detection device and a radon concentration detection method. The ionization radon detection device comprises: an ionization chamber, at least a part of the ionization chamber is open to form an opening, so that the air to be detected flows into the inner cavity of the ionization chamber; a probe piece, the probe piece is arranged in the inner part of the ionization chamber and is not in electrical contact with the ionization chamber, and the probe piece is used for pulse detection of ion charges generated by alpha particles generated during alpha decay of radon in the air staying in the inner part of the ionization chamber; and a dry filter part, the dry filter part covers the opening, and the dry filter part is configured to allow radon molecules to pass through and block water molecules. The problem that the ionization chamber of the prior art cannot dehumidify, resulting in inaccurate radon concentration detection results in a high-humidity environment, is solved.

Description

Technical Field

[0001] This application relates to the field of magnetic field measurement technology, and more specifically, to an ionization radon gas detection device and a method for detecting radon gas concentration. Background Technology

[0002] In some locations (such as underground spaces and mining workshops), it is necessary to detect the concentration of radon gas in the environment. Since the frequency of alpha particles produced when radon (Rn) decays is proportional to the radon concentration, the indoor radon concentration is measured by detecting alpha particles in the air.

[0003] Alpha particle detection technology using pulsed ionization chambers exists in the prior art. The structure of a pulsed ionization chamber involves mounting probe-shaped electrodes inside a metal casing and creating an electric field by applying a bias voltage between the metal cylinder and the internal probes. When alpha decay occurs within the ionization chamber and emits alpha particles, these particles annihilate upon collision with air, but generate ionic charges. These charges can then be absorbed by the central probe and the signal amplified to detect the alpha particles.

[0004] In existing radon concentration detection using continuous radon sensors based on ionization chambers, the output results are highly susceptible to environmental humidity. Specifically, the detection efficiency of the ionization chamber is greatly affected by air humidity. In high-humidity environments, the increase in water molecules in the air leads to a faster recombination rate of ions generated within the ionization chamber, resulting in a smaller pulse amplitude detected by the probe. Simultaneously, high humidity can also cause pulse distortion or even signal loss. This signal attenuation caused by humidity changes leads to a change in the net count rate of the radon sensor even when the actual radon concentration remains constant, resulting in a calculated radon concentration that is either too high or too low.

[0005] In actual testing, existing ionization chamber structures typically do not take dehumidification into account, resulting in inaccurate radon concentration detection results in complex environments (especially high-humidity environments), failing to meet the requirements for high-precision monitoring.

[0006] Therefore, existing technologies still need to be improved and developed. Summary of the Invention

[0007] The purpose of this application is to provide an ionization-type radon detection device and a radon concentration detection method, which solves the problem that the existing ionization chamber cannot dehumidify, resulting in inaccurate radon concentration detection results in high humidity environments.

[0008] To achieve the above objectives, the technical solution adopted in this application is as follows: On one hand, this application provides an ionized radon gas detection device, comprising: An ionization chamber, at least part of which is open to form an opening, so that the air to be detected can flow into the inner cavity of the ionization chamber; The probe is located inside the ionization chamber and does not make electrical contact with the ionization chamber. The probe is used to pulse-detect the ionic charge generated by alpha particles produced during the alpha decay of radon gas in the air inside the ionization chamber. The drying filter section covers the opening and is configured to allow radon molecules to pass through while blocking water molecules.

[0009] Optionally, the drying filter section includes a hydrophobic and breathable membrane layer that covers the openings, the pore size of which allows radon molecules to pass through while blocking water molecules.

[0010] Optionally, the hydrophobic and breathable membrane layer also includes a dust-collecting mesh layer, which is disposed on the inner side of the hydrophobic and breathable membrane layer and covers the opening; The dust collection mesh is electrically connected to the ionization chamber and uses the voltage on the ionization chamber to adsorb the dust inside the ionization chamber.

[0011] Optionally, the ionization radon detection device further includes a pulse processing unit electrically connected to the probe, used to count the number of pulses of alpha particles detected by the probe, in order to obtain the indoor radon concentration by combining humidity compensation.

[0012] Optionally, the pulse processing unit is configured to: determine whether the potential of the electrical signal input from the probe is greater than a preset pulse generation reference voltage; if the potential of the electrical signal is higher than the pulse generation reference voltage, then set the potential at the moment when the voltage change per unit time changes from positive to negative as the first maximum voltage. If a voltage lower than a preset critical potential difference is detected after the first maximum voltage occurs, it can be determined that a pulse was detected at the first maximum voltage occurrence time. If the potential of the electrical signal is detected to be lower than the pulse generation reference voltage after the first maximum voltage occurs, the number of pulses will not be counted until the potential of the electrical signal is higher than the pulse generation reference voltage again.

[0013] On the other hand, this application also proposes a radon concentration detection method, which is applied to the ionization radon detection device described above. The radon concentration detection method includes the following steps: The radon concentration value Ccalc detected in the ionization chamber is obtained through a probe. The detected radon concentration value Ccalc is compensated by a correction factor K to obtain the output radon concentration value Ccorr, where: Ccorr = Ccalc *K, K=1 / exp( -b * ( H - Href ) ), where b is the humidity compensation coefficient, H is the current humidity, and Href is the reference humidity.

[0014] Optionally, in the step of acquiring the detected radon concentration value Ccalc in the ionization chamber via the probe: Basic calibration was performed under a reference environment to obtain the detected radon concentration value Ccalc; Where Ccalc = a + F * Rnet; a is the zero-point term or background correction term, F is the baseline calibration factor, and Rnet is the baseline net count rate.

[0015] Optionally, before the step of compensating the detected radon concentration value Ccalc with the correction coefficient K to obtain the output radon concentration value Ccorr, the correction coefficient K is obtained in advance; The steps to obtain the correction factor K in advance include: Detection was performed at multiple humidity points, and the average humidity H (current humidity H), average measured radon concentration Cpr, and average net count rate Rnet1 were recorded after stabilization. Compare the deviations between the average measured radon concentration Cpr and the reference radon value Cref at each humidity point; The relationship between the deviation value and the humidity point is fitted by an exponential model, and the humidity compensation coefficient b is obtained based on the fitting result. The correction factor K is obtained based on the humidity compensation factor b, the reference humidity Href, and the current humidity H; Where K = 1 / exp( -b * ( H - Href ).

[0016] Optionally, in the step of completing the basic calibration under a reference environment to obtain the detected radon concentration value Ccalc, the reference humidity of the reference environment Href = 40%RH; In the step of compensating for the detected radon concentration value Ccalc using a correction coefficient K to obtain the output radon concentration value Ccorr: Ccorr = Ccalc / exp( -0.008 * ( H-40 ) ).

[0017] Optionally, in the step of detecting at multiple humidity points, the detection is performed at multiple humidity points within the linear stability region of radon concentration, wherein the linear stability region is 1000 Bq / m³. 3 Up to 3000 Bq / m 3 .

[0018] The beneficial effects of the ionization-type radon detection device and radon concentration detection method provided in this application are at least as follows: the air to be detected enters the ionization chamber through a drying filter. The drying filter physically intercepts most of the water molecules in the air, allowing only radon molecules and dry air to enter the ionization chamber, thus dehumidifying the high-humidity air. When radon undergoes alpha decay in the ionization chamber, the released alpha particles ionize the gas in the ionization chamber, generating positive and negative ions. The probe collects these ion charges under the influence of an electric field and converts them into electrical pulse signals. Therefore, by using a drying filter to block water molecules, the direct entry of high-humidity external air into the ionization chamber is prevented at the source, effectively avoiding the problems of reduced pulse amplitude and pulse shape distortion caused by accelerated ion recombination in high-humidity environments. This significantly improves the detection efficiency and measurement stability of the ionization chamber in complex humidity environments. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 A cross-sectional view of an ionized radon gas detection device provided in an embodiment of this application; Figure 2 An exploded view of an ionizing radon gas detection device provided in an embodiment of this application; Figure 3 A schematic diagram of the mesh distribution of the dust collection mesh layer in an ionizing radon gas detection device provided in an embodiment of this application; Figure 4 A circuit block diagram of an ionization radon gas detection device provided in this application embodiment; Figure 5 A flowchart illustrating the main steps of a radon concentration detection method provided in this application embodiment; Figure 6 This is a flowchart illustrating the steps of obtaining the correction coefficient K in advance for a radon concentration detection method provided in this application embodiment.

[0021] The following are the labeling elements in the figure: 100 Ionization chamber; 110 Opening; 200 Probe element; 210 BNC connector; 300 Drying and filtering section; 310 Hydrophobic and breathable membrane layer; 320 Dust collection mesh layer; 321 Mesh; 400 Pulse processing section. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or specifying the number of technical features. "Multiple" means two or more, unless otherwise explicitly specified.

[0024] like Figure 1 , Figure 2As shown, this embodiment proposes an ionization-type radon gas detection device, which mainly includes an ionization chamber, a probe, and a drying and filtering section. At least a portion of the ionization chamber is open, forming an opening to allow the air to be detected to flow naturally or diffuse passively into the inner cavity of the ionization chamber. Specifically, the ionization chamber is a cylindrical metal structure, with one end open to allow airflow into the chamber and the other end connected to the probe. The probe extends axially into the interior of the ionization chamber, collecting alpha particles. At least a portion of the probe is disposed inside the ionization chamber, and the probe is insulated from the chamber wall, preventing electrical contact with the ionization chamber. The probe is used to pulse-detect the ion charge excited by alpha particles generated during the alpha decay of radon gas in the air residing inside the ionization chamber. Specifically, the probe can be physically encased and electrically shielded by an insulating shield to prevent external noise from flowing into the probe. The insulating shield can use a BNC connector, providing an insulated shield for the probe connection to the ionization chamber while maintaining a physical connection. Ferrite beads or common-mode chokes are added at the BNC connector connections to other signal receiving devices to effectively suppress high-frequency RF noise entering through the cable shield. This allows the probe to be suspended within the ionization chamber, transmitting pulses only through the signal pins of the BNC connector. The shield of the BNC connector is grounded at a single point, and EMI filtering can be added at the circuit board entrance. This ensures the accuracy of the pulse signals collected by the probe. A drying filter covers the opening of the ionization chamber. This filter is configured to allow radon molecules to pass through while blocking water molecules, allowing air from the detection area to still flow into the ionization chamber. The air to be tested enters the ionization chamber through the drying filter, which physically intercepts most water molecules in the air, allowing only radon molecules and dry air to enter the ionization chamber. Radon gas undergoes alpha decay within the ionization chamber, releasing alpha particles that ionize the gas inside, generating positive and negative ion pairs. The probe collects these ion charges under the influence of an electric field and converts them into electrical pulse signals. This effectively blocks the direct entry of high-humidity external air into the ionization chamber, avoiding the problems of reduced pulse amplitude and pulse shape distortion caused by accelerated ion recombination in high humidity environments. This significantly improves the detection efficiency and measurement stability of the ionization chamber in complex humidity environments.

[0025] like Figure 1 , Figure 2 As shown, the drying and filtration section further includes a hydrophobic and breathable membrane layer covering the opening. The pore size of this membrane layer is precisely set to allow radon gas molecules to pass through while blocking liquid water and water molecule clusters. The hydrophobic and breathable membrane layer can be a PTFE (polytetrafluoroethylene) membrane, a glass fiber filter membrane, or a quartz fiber filter membrane, etc. Utilizing the principles of surface tension and pore size sieving effect, the hydrophobic and breathable membrane layer can achieve efficient gas-water separation while ensuring smooth diffusion of radon gas into the ionization chamber, thereby achieving dehumidification.

[0026] like Figure 1 , Figure 2 , Figure 3 As shown, further, based on the hydrophobic and breathable membrane layer, the drying and filtering section also includes a dust-collecting mesh layer. The dust-collecting mesh layer is located inside the hydrophobic and breathable membrane layer and covers the opening. Firstly, the dust-collecting mesh layer uses a perforated metal mesh with small pores, which physically blocks dust. Secondly, the dust-collecting mesh layer is electrically connected to the ionization chamber, utilizing the electrostatic field applied to the ionization chamber to adsorb dust particles entering the chamber. If dust particles in the air enter the ionization chamber and adhere to the probe or chamber wall, they will generate background noise and interfere with the pulse detection of alpha particles. This solution cleverly utilizes the high-voltage electric field of the ionization chamber itself, enabling the dust-collecting mesh layer to also function as an electrostatic dust collector. It intercepts and adsorbs the dust carried by radon gas before it enters the ionization chamber, effectively reducing the detector's background noise and further improving the signal-to-noise ratio and detection accuracy.

[0027] like Figure 1 , Figure 3 As shown, this solution utilizes a combination of a dust-absorbing mesh layer and a hydrophobic and breathable membrane layer to improve the water absorption and dust removal effect in two ways. First, because the ionization chamber applies voltage during operation, the charge on the outer shell of the ionization chamber can charge the hydrophobic and breathable membrane layer at the opening. To achieve hydrophobicity, the fibers with the same charge in the hydrophobic and breathable membrane layer repel each other, and the original short fibers at the loose edges of the membrane layer are carried away by the airflow, becoming particulate matter in the air. These particles need to pass through the dust-absorbing mesh layer to enter the circuit chamber, and the mesh layer effectively isolates and adsorbs these particles detached from the hydrophobic and breathable membrane layer, preventing them from affecting the probe's detection data. Second, the ionization chamber can block and adsorb solid radon progeny (Po218 / Po214), preventing solid radon progeny (Po218 / Po214) from decaying in the filter membrane and entering the probe in the ionization chamber, causing falsely high readings and data drift.

[0028] like Figure 3As shown, in some embodiments, the mesh distribution on the suction mesh layer has also been structurally improved. In the radial direction of the opening of the ionization chamber, the mesh on the suction mesh layer gradually becomes denser towards the orthographic projection of the probe on the opening plane. For example, the probe is usually located at the central axis of the ionization chamber, so the orthographic projection of the probe on the opening plane is at the center. When the suction mesh layer covers the opening, the orthographic projection of the probe is located at the center of the suction mesh layer. Therefore, in the radial direction, the mesh on the suction mesh layer becomes denser towards the center and sparser towards the edges. This design, in addition to blocking and adsorbing solid radon protons (Po218 / Po214) through the dust-collecting mesh layer, also enhances the protection of the probe. Specifically, the denser the mesh near the probe, the more effective the blocking effect becomes, and the more concentrated the charge at that location. This generates a greater electrostatic attraction to the solid radon protons floating in that area. Under this attraction, the dust-solid radon protons floating around the probe can be adsorbed onto the densely distributed mesh of the dust-collecting mesh layer, providing better dust protection for the probe. The mesh openings are more sparse near the outer edge of the dust collection mesh, facilitating the flow of air from outside the opening into the ionization chamber. For dust-solid radon protons near the outer edge of the dust collection mesh, in addition to the adsorption effect of the dust collection mesh itself, the inner wall of the ionization chamber at the opening also provides electro-adsorption. This combined effect of the sparse mesh at the outer edge of the dust collection mesh and the inner wall of the ionization chamber at the opening effectively coordinates air intake and dust collection. Furthermore, the densely distributed mesh near the probe on the dust collection mesh optimizes both dust protection for the probe and air intake into the ionization chamber.

[0029] To achieve the effect of increasingly denser mesh openings towards the center and increasingly sparser openings towards the edges in the dust collection mesh layer, the mesh openings can be made to have different sizes. The openings become smaller towards the center (closer to the probe) and larger towards the edges (away from the probe). By setting different mesh opening sizes, the aforementioned structure of dense distribution at the center and sparse distribution at the edges can be achieved.

[0030] In some embodiments, the material of the dust-collecting mesh layer is improved. This mesh layer can be made of a material that absorbs β-particles (high-speed electrons), such as an aluminum mesh layer. Besides dust collection, it can also absorb other interfering particles within the ionization chamber, thereby reducing the influence of these particles on the probe and further improving the accuracy of concentration detection. Improving both the mesh size and the material of the dust-collecting mesh layer simultaneously makes the measurement more precise.

[0031] like Figure 4As shown, the ionizing radon detection device further includes a pulse processing unit, which is electrically connected to the probe. This unit counts the number of pulses of alpha particles detected by the probe and combines this count with a humidity compensation algorithm to obtain the final indoor radon concentration. By introducing the pulse processing unit, physical dehumidification at the hardware level is combined with a humidity compensation algorithm at the software level, forming a dual anti-humidity mechanism integrating hardware and software. Even under extreme humidity conditions, if a small amount of water vapor still penetrates the drying filter, the pulse processing unit can correct this through the algorithm, ensuring the absolute accuracy of the output results. The specific temperature compensation process is described in detail below.

[0032] In some embodiments, after the probe device performs pulse detection of ion charge in the ionization chamber, the pulse processing unit further processes the pulses measured by the probe device to achieve accurate pulse counting without omissions. Specifically: Determine whether the electrical signal potential input from the probe is greater than the preset pulse generation reference voltage; if it is higher than the reference voltage, set the potential at the moment when the voltage change per unit time changes from positive (+) to negative (-) as the first maximum voltage.

[0033] If a voltage below a preset critical potential difference is detected after the first maximum voltage occurs, a valid pulse is determined to have been detected at that moment. If the electrical signal potential is lower than the pulse generation reference voltage after the first maximum voltage occurs, pulse counting will not be performed until the potential rises above the reference voltage again.

[0034] After the pulse processing unit detects a voltage below the critical potential difference, if the voltage change of the electrical signal per unit time becomes positive (+) again, the potential at the moment when the voltage change of the electrical signal per unit time becomes negative (-) again is set as the second maximum voltage. If a voltage below the preset critical potential difference is detected after the second maximum voltage occurs, it is determined that a pulse was detected at the second maximum voltage occurrence time.

[0035] To address pulse morphology distortion and tailing phenomena that may occur in high humidity environments, this discrimination logic can accurately identify real alpha particle pulses by capturing the peak characteristic of "voltage change rate turning from positive to negative" and the subsequent "critical potential difference" drop characteristic. It effectively filters out noise interference and false pulses caused by humidity, avoids duplicate counting or missed counting, and greatly improves the anti-interference capability of pulse processing.

[0036] The specific processing procedure is as follows: Assuming the reference voltage for determining whether a pulse has occurred ("pulse occurrence reference voltage") is 1.5V, when the input signal voltage exceeds 1.5V (time A), the pulse processing unit searches for the moment after time A when the maximum voltage is detected (time B). The moment when the maximum voltage is detected can be determined by finding the moment before that moment (e.g., time B) when the voltage change per unit time is positive (+), and the voltage change per unit time after that moment (e.g., time B) is negative (-). In other words, the moment when the voltage starts to decrease after a continuous rise is the moment of maximum voltage.

[0037] Set time B as the "first maximum voltage time". Then, if a voltage lower than the first maximum voltage time (time B), i.e., a voltage lower than the first maximum voltage by a preset "critical potential difference" (e.g., 0.025V lower at time C), it is considered a pulse detected. If the potential difference from the first maximum voltage is less than 0.025V, it is judged as noise and no special processing is performed.

[0038] If the input signal voltage drops below the pulse generation reference voltage of 1.5V (time D), pulse counting is not performed until an input signal above 1.5V is detected again. If the voltage rises again when the input signal voltage is above 1.5V, the "second maximum voltage moment" is searched. That is, at time E, the voltage change per unit time becomes positive (+) again, so the moment when the second maximum voltage occurs (time F) will occur after time E and before the voltage change per unit time becomes negative (-) again. Time F is set as the "second maximum voltage moment". As before, if a voltage 0.025V lower than the second maximum voltage moment is detected (time G), it is determined that an additional pulse has occurred.

[0039] In this way, by determining whether the voltage change per unit time changes from positive (+) to negative (-), multiple alpha particles occurring at extremely close time intervals can be detected. This is based on the mathematical principle of continuous and differentiable functions, namely, that there must exist upward convex points (such as the point at time B and the point at time F) between the intervals of positive (+) and negative (-) changes per unit time. Thus, through the unique configuration and processing algorithm in the pulse processing unit, the number of occurring pulses can be counted without omission, thereby improving measurement accuracy even when alpha particles occur in minute, continuous bursts, thanks to the combination of the drying filter unit and the processing algorithm.

[0040] like Figure 5 As shown, in some embodiments, a radon concentration detection method is also proposed, applied to the aforementioned ionization-type radon detection device. The method includes the following steps: Step S100: Obtain the radon concentration value Ccalc detected in the ionization chamber through the probe device.

[0041] Step S200: Compensate Ccalc with correction coefficient K to obtain the output radon concentration value Ccorr.

[0042] Specifically, the compensation formula is: Ccorr = Ccalc * K, and K = 1 / exp( -b * ( H - Href ) ), where b is the humidity compensation coefficient, H is the current ambient humidity, and Href is the reference humidity. An exponential model is used to compensate for the decrease in detection efficiency caused by humidity, which closely matches the physical law that the ion recombination rate increases non-linearly under high humidity. This formula can dynamically and accurately eliminate the deviation between the current humidity H and the reference humidity Href, ensuring that the final output radon concentration value is unaffected by fluctuations in ambient humidity.

[0043] For example, temperature and humidity sensors can be used to collect ambient temperature data, a mathematical model can be established for correction, and counting efficiency curves under different humidity levels can be established through experimental calibration. A correction coefficient K can be introduced to correct for radon concentration (actual radon concentration = detected concentration x K) or for the pulse count detected by the probe (actual count = detected count x K). The higher the humidity, the larger the value of K. Furthermore, combined with the above-mentioned pulse distortion processing, rise time and pulse width analysis can be introduced. The ion pulses generated by radon gas usually have specific rise time characteristics. By locking this characteristic through the above processing, irregular noise caused by humidity can be effectively eliminated.

[0044] Furthermore, the correction coefficient K is obtained in advance before the correction process is carried out.

[0045] like Figure 6 As shown, the steps to obtain the correction coefficient K in advance include: Step S10: Detect at multiple humidity points and record the average humidity H, average measured radon concentration Cpr, and average net count rate Rnet1 after stabilization.

[0046] In the specific process, a reference humidity is first set, for example, Href = 40%RH. This ensures that subsequent tests, fitting, and compensation operations are all performed around this reference point. When testing humidity compensation, try to allow only the humidity to change while keeping other conditions stable. Specifically, the reference radon concentration Cref must remain stable. After switching to each humidity point, wait for the environment to stabilize before starting data collection. Only use data from the stable phase, and do not use transitional data during the switching process.

[0047] Test at least three humidity points: low humidity, such as 30%RH; reference humidity, such as 40%RH; and high humidity, such as 75%RH to 80%RH. You can also add more humidity points, such as 50%RH, 60%RH, and 70%RH, so that the fitted data model is more stable.

[0048] During testing, the linear stability region of radon concentration was selected, for example, set to 1000 Bq / m³ to 3000 Bq / m³. If the concentration is too low, the count fluctuations are large, resulting in high noise; if the concentration is too high, it may enter the nonlinear or saturation region. Therefore, calibration within the linear stability region of 1000 to 3000 Bq / m³ ensures the detector is in its optimal response range, avoiding nonlinear errors caused by excessive statistical fluctuations at extremely low concentrations or pulse accumulation effects at extremely high concentrations. The humidity compensation coefficient 'b' obtained by fitting within this range has the highest confidence and universality, ensuring the reliability of the compensation model.

[0049] Step S20: Compare the deviation between the average measured radon concentration Cpr at each humidity point and the reference radon value Cref.

[0050] This allows us to compare changes in humidity levels at different points relative to a reference humidity.

[0051] Step S30: Fit the relationship between the deviation value and the humidity point using an exponential model, and obtain the humidity compensation coefficient b based on the fitting result.

[0052] Step S40: Obtain the correction coefficient K based on the humidity compensation coefficient b, the reference humidity Href, and the current humidity H.

[0053] Where K = 1 / exp( -b * ( H - Href ).

[0054] Through multi-point humidity calibration and exponential model fitting, the humidity compensation coefficient b for a specific instrument was scientifically and objectively determined. This compensation coefficient, obtained based on measured data fitting, fully considers the individual differences in probe components and ionization chamber structures from different batches, making humidity compensation more personalized and accurate.

[0055] With a reference humidity Href = 40%RH, the humidity compensation coefficient b can be 0.008. The corresponding compensation formula is: Ccorr = Ccalc / exp( -0.008 * ( H - 40 ) ). 40%RH is a typical and suitable reference humidity standard for indoor environments. By embedding the reference humidity and compensation coefficient b (0.008) into the algorithm, the device's operational logic is simplified, data processing efficiency is improved, and detection accuracy is ensured within the normal indoor humidity fluctuation range.

[0056] The measured radon concentration value Ccalc is temperature-corrected using the aforementioned correction factor K. Specifically, during equipment operation, the net count rate Rnet is read. The measured radon concentration value Ccalc (uncompensated concentration) is calculated using the basic calibration formula (the formula for calculating the uncompensated concentration).

[0057] Perform basic calibration under reference conditions to obtain the uncompensated concentration calculation formula (basic calibration formula): Ccalc = a + F * Rnet. Where a is the zero-point term or background correction term, F is the basic calibration factor, and Rnet is the reference net count rate. By introducing the zero-point term a and the basic calibration factor F, the instrument's own background radiation and inherent system errors are eliminated, ensuring the absolute accuracy of basic measurement data under standard reference conditions and providing reliable reference data support for subsequent dynamic humidity compensation.

[0058] Furthermore, the current humidity H is read, and the detected radon concentration value Ccalc is substituted into the humidity compensation formula. Compensation is performed using a correction coefficient K to obtain the output radon concentration value Ccorr (the compensated concentration).

[0059] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An ionization-type radon gas detection device, characterized in that, include: An ionization chamber, at least a portion of which is open to form an opening, allowing the air to be detected to flow into the inner cavity of the ionization chamber; The probe is disposed inside the ionization chamber and is not in electrical contact with the ionization chamber. The probe is used to perform pulse detection on the ionic charge generated by alpha particles produced during the alpha decay of radon gas in the air inside the ionization chamber. A drying filter section that covers the opening and is configured to allow radon molecules to pass through while blocking water molecules.

2. The ionization radon gas detection device as described in claim 1, characterized in that, The drying and filtration section includes a hydrophobic and breathable membrane layer that covers the opening, the pore size of which allows radon molecules to pass through while blocking water molecules.

3. The ionization radon gas detection device as described in claim 2, characterized in that, The hydrophobic and breathable membrane layer also includes a dust-collecting mesh layer, which is disposed on the inner side of the hydrophobic and breathable membrane layer and covers the opening; The dust-collecting mesh layer is electrically connected to the ionization chamber. The dust is blocked through the mesh of the dust-collecting mesh layer, and the dust in the ionization chamber is adsorbed by the voltage on the ionization chamber.

4. The ionization radon gas detection device as described in any one of claims 1-3, characterized in that, The ionization radon gas detection device further includes a pulse processing unit, which is electrically connected to the probe and is used to count the number of pulses of alpha particles detected by the probe to obtain the indoor radon concentration in combination with humidity compensation.

5. The ionization radon gas detection device as described in claim 4, characterized in that, The pulse processing unit is configured to: determine whether the potential of the electrical signal input from the probe is greater than a preset pulse generation reference voltage; if the potential of the electrical signal is higher than the pulse generation reference voltage, then set the potential at the moment when the voltage change per unit time changes from positive to negative as the first maximum voltage. If a voltage lower than a preset critical potential difference is detected after the first maximum voltage occurs, it can be determined that a pulse was detected at the first maximum voltage occurrence time. If the potential of the electrical signal is detected to be lower than the pulse generation reference voltage after the first maximum voltage occurs, the number of pulses is not counted until the potential of the electrical signal is again higher than the pulse generation reference voltage.

6. A method for detecting radon gas concentration, characterized in that, Applied to the ionization-type radon detection device as described in any one of claims 1-5, the radon concentration detection method includes the following steps: The radon concentration value Ccalc detected in the ionization chamber is obtained through a probe. The detected radon concentration value Ccalc is compensated by a correction factor K to obtain the output radon concentration value Ccorr, where: Ccorr = Ccalc *K, K=1 / exp( -b * ( H - Href ) ), where b is the humidity compensation coefficient, H is the current humidity, and Href is the reference humidity.

7. The ionization radon gas detection device as described in claim 6, characterized in that, In the step of obtaining the detected radon concentration value Ccalc in the ionization chamber through the probe: Basic calibration was performed under a reference environment to obtain the detected radon concentration value Ccalc; Where Ccalc = a + F * Rnet; a is the zero-point term or background correction term, F is the baseline calibration factor, and Rnet is the baseline net count rate.

8. The ionization radon gas detection device as described in claim 6, characterized in that, Before the step of compensating the detected radon concentration value Ccalc with the correction factor K to obtain the output radon concentration value Ccorr, the correction factor K is obtained in advance; The steps to obtain the correction coefficient K in advance include: Detection was performed at multiple humidity points, and the average humidity H, average measured radon concentration Cpr, and average net count rate Rnet1 were recorded after stabilization. Compare the deviations between the average measured radon concentration Cpr and the reference radon value Cref at each humidity point; The relationship between the deviation value and the humidity point is fitted by an exponential model, and the humidity compensation coefficient b is obtained based on the fitting result. The correction factor K is obtained based on the humidity compensation factor b, the reference humidity Href, and the current humidity H; Where K = 1 / exp( -b * ( H - Href ).

9. The ionization radon gas detection device as described in claim 8, characterized in that, In the step of completing the basic calibration under the reference environment to obtain the detected radon concentration value Ccalc, the reference humidity of the reference environment is Href = 40%RH; In the step of compensating the detected radon concentration value Ccalc with a correction coefficient K to obtain the output radon concentration value Ccorr: Ccorr = Ccalc / exp( -0.008 * ( H-40 ) ).

10. The ionization radon gas detection device as described in claim 8, characterized in that, In the step of detecting humidity at multiple points, the humidity is measured at multiple points within the linear stability region of radon concentration, wherein the linear stability region is 1000 Bq / m³. 3 Up to 3000 Bq / m 3 .

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