JP4627650B2 - Radiation measuring instrument - Google Patents

Description

  The present invention relates to a radiation measuring instrument, and more particularly to a technique for removing or reducing the influence of electrostatic noise.

  In a radiation measuring instrument such as a survey meter, generally, a moving average process (smoothing process) for a series of measurement values is applied. That is, a plurality of measurement values within a moving average period that goes back from the present to the past are used, and a moving average process that smoothes the waveform or suppresses background noise is applied to them. By such processing, it is possible to prevent the noise from appearing directly in the display value (indication value) displayed in real time and the display value from fluctuating greatly. Patent Document 1 and Patent Document 2 below describe dynamically setting the moving average period according to the situation.

  Radiation measuring instruments using ionization chambers are generally susceptible to static electricity. For example, when static electricity flows through the ionization chamber, the DC voltage applied to the ionization chamber fluctuates, and the effect appears in the output signal of the ionization chamber. Therefore, it is desirable to prevent the influence of static electricity from appearing as much as possible on the display value displayed in real time, and it is desirable to prevent a waveform due to static electricity from being taken into the object of the moving average process.

  Patent Document 3 below describes that noise removal is performed with reference to the pulse width in radiation measurement. Patent Document 4 below describes that, in radiation measurement, noise is removed using the area of a waveform using software processing. However, none of Patent Documents 1 to 4 describes an effective countermeasure against static electricity.

JP 7-134180 A JP-A-10-82860 JP 2004-212337 A Japanese Patent Laid-Open No. 9-80084

  An object of the present invention is to eliminate or reduce the influence of static electricity in the measurement of radiation.

  Another object of the present invention is to prevent the influence of static electricity from appearing as much as possible on the display value displayed in real time.

  Another object of the present invention is to prevent or reduce the influence of static electricity from remaining after the occurrence of static electricity so that the measurement value corresponding to static electricity is excluded from the moving average processing target.

  The present invention obtains a moving average value at each time by performing a moving average process on a plurality of measured values within a moving average period and a measured value output means for outputting a measured value at each time by measuring radiation. A moving average processing means, a moving average value at each time, a first waveform portion detecting means for detecting a first waveform portion in a characteristic waveform caused by static electricity, and a moving average value at each time are sequentially monitored. A second waveform portion detecting means for detecting a second waveform portion following the first waveform portion in the intrinsic waveform caused by static electricity, and when the second waveform portion is detected following the first waveform portion, And an exclusion processing means for performing an exclusion process for excluding a plurality of measurement values obtained within a period corresponding to the natural waveform from the target of the subsequent moving average process.

  In the above configuration, the measurement value output means is preferably configured as an ionization chamber, but may be another measurement device. The moving average period is a fixed period or a variable period. For example, it is desirable that the moving average period is adaptively set on the basis of variations or dispersion of measured values. The waveform of noise caused by static electricity (electrostatic noise) has a specific form, and in the above configuration, by appropriately detecting the first waveform portion and the second waveform portion of the specific waveform, appropriate exclusion processing, etc. Can be achieved. Although it is possible to detect each waveform part based on the measured value at each time (value before moving average processing), the measured value fluctuates considerably in the background level, and in such a situation, electrostatic noise Therefore, each waveform portion is detected based on the moving average value after the moving average process.

  According to the above configuration, when the second waveform portion is detected subsequent to the first waveform portion, it is determined that the noise is not a true signal but electrostatic noise, and a plurality of pieces existing within a period corresponding to the electrostatic noise are detected. The measured value is excluded from the subsequent moving average process. Therefore, the exclusion process can solve the problem that the moving average process cannot be performed properly due to the influence of electrostatic noise. In other words, it is possible to forcibly eliminate the remaining effects after the occurrence of electrostatic noise. The exclusion process may simply exclude a plurality of measurement values, or may insert a dummy value after the exclusion. In the above configuration, since the detection of the second waveform portion is used in addition to the detection of the first waveform portion, accurate exclusion processing can be performed.

  Preferably, a normal display process for displaying a moving average value at each time in a normal period is executed, and at each time in a period from when the first waveform portion is detected until the presence or absence of the second waveform portion is determined. Display processing means for executing a temporary display process for displaying the temporary moving average value instead of the moving average value is included.

  According to the above configuration, at the stage where the first waveform portion is detected and the possibility of occurrence of electrostatic noise has come out, it is determined that the entire second waveform portion of electrostatic noise has been detected or that it has not been electrostatic noise. Until this is done, the provisional moving average value can be displayed temporarily. Here, the first waveform portion is basically displayed as it is. The true signal may have a form close to the first waveform portion. If the first waveform portion is not displayed, the true signal may not be displayed. However, according to the above configuration, the true signal is not displayed. The display can be secured. In addition, it is possible to avoid the display of the second waveform portion and partially optimize the display content, thereby reducing user misidentification. When the second waveform portion cannot be detected within a certain period, the normal display process is resumed as the period elapses.

  Preferably, the first waveform portion is a rising portion in the natural waveform due to the static electricity, and the second waveform portion is a falling portion in the natural waveform due to the static electricity. The rising portion and the falling portion can generally be detected by recognizing a plurality of feature points. The last feature point of the rising portion may coincide with the first feature point of the falling portion. It should be noted that feature quantities such as waveform gradients or fluctuation trends can be used.

  Preferably, the provisional moving average value is based on a past moving average value before the characteristic waveform caused by the static electricity. In that case, a moving average value immediately before the eigen waveform can be used, or an average value of a plurality of moving average values before the eigen waveform can be used.

  Desirably, the display processing means ends the provisional display processing and returns to the normal display processing when the second waveform portion is not detected within a predetermined period after the first waveform portion. According to this configuration, it is possible to prevent an increase in the period during which real-time display cannot be performed when the second waveform portion cannot be detected for some reason.

  Preferably, the first waveform portion detection unit recognizes an initial point of the first waveform portion by comparing moving average values adjacent in time, and recognizes a reference point immediately before the initial point. And a means for recognizing a descent point of the first waveform portion by comparing a moving average value of the reference point and a moving average value at each time, and the initial point and the descent point are recognized. If it is, it is regarded as detection of the first waveform portion.

  In the above configuration, the first waveform portion can be detected quickly and easily by recognizing the initial point and the descending point. Of course, the detection accuracy of the first waveform portion may be increased by recognizing more points.

  Preferably, the second waveform portion detection means includes means for recognizing an end point of the second waveform portion by comparing the moving average value of the reference point and the moving average value at each time, When the end point is recognized within a certain period of time after the point, it is regarded as the detection of the second waveform portion.

  In the above configuration, the second waveform portion can be detected quickly and easily by recognizing the end point after the descending point (or by recognizing the descending point and the end point). Of course, the detection accuracy of the second waveform portion may be increased by recognizing more points.

  Preferably, in the exclusion process, a plurality of measured values from the initial point to the end point are excluded from the moving average process. Preferably, the moving average value of the reference point is displayed instead of the moving average value at each time in the period from the descending point to the end point.

  As described above, according to the present invention, the influence of static electricity can be excluded or reduced in the measurement of radiation. According to the present invention, it is possible to prevent the influence of static electricity from appearing as much as possible on the display value displayed in real time. Alternatively, according to the present invention, a measurement value corresponding to static electricity can be excluded from the moving average processing target, so that the influence of static electricity can be prevented or reduced after the static electricity is generated.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to the drawings.

  FIG. 1 shows a preferred embodiment of a radiation measuring instrument according to the present invention, and FIG. 1 is a conceptual diagram showing the overall configuration thereof. This radiation measuring instrument is a survey meter that detects radiation indoors or outdoors. The radiation to be measured is, for example, γ-ray, but of course other radiation such as β-ray may be the measurement target.

  The radiation measuring instrument has an ionization chamber 10 and a signal calculation unit 12. The ionization chamber 10 functions as a radiation detector, and the signal calculation unit 12 includes an electrometer circuit 29 and a signal processing circuit. In the present embodiment, the detected signal is converted into a digital signal, and a measurement result is obtained for the signal by software processing. In addition, you may make it detect a radiation using systems other than an ionization chamber system. In this embodiment, a charge storage type electrometer circuit 29 using a capacitor is used. However, for example, a circuit configuration according to a current-voltage conversion method using a resistor may be employed.

  The ionization chamber 10 has a container 14. The container 14 is made of, for example, ABS resin, and an electrode layer 16 is formed on the inner surface thereof. The electrode layer 16 constitutes a container electrode. A collector electrode 18 is disposed inside the ionization chamber 10. Reference numeral 24 in the drawing represents a guard ring for improving insulation. A voltage is applied between the electrode layer 16 and the collector electrode 18 by the power source 22. The voltage is, for example, 30 V. Of course, a higher voltage than that may be applied. In a state where a voltage is applied between the electrode layer 16 and the collector electrode 18, when the radiation 26 enters the inside of the ionization chamber 10, the gas in the ionization chamber 10 is thereby ionized, thereby collecting the collector 18. The charge is collected. The electric charge is output from the ionization chamber 10 to the electrometer circuit 29 in the signal calculation unit 12.

  When static electricity is generated, for example, the voltage between the electrode layer 16 and the collector electrode 18 fluctuates, and static noise is generated. Such electrostatic noise causes an adverse effect in the calculation of a true signal, and it is necessary to exclude it as much as possible. Processing for this is provided in the signal calculation unit 12. This will be described in detail later.

  The electrometer circuit 29 includes a capacitor C and a preamplifier 30. The electrometer circuit 29 outputs a voltage signal corresponding to the amount of charge accumulated in the capacitor C to the ADC 32.

  FIG. 2 shows a temporal change in the amount of charge accumulated in the capacitor C. (A) has shown the characteristic at the time of irradiating the radiation from the radiation source to the ionization chamber part 10, and (B) has shown the case by static electricity. In all of the characteristics, the value rises to the right. This indicates that electric charges are gradually accumulated in the capacitor C due to the background. As shown in (A), when radiation from the radiation source is irradiated at the timing indicated by reference numeral 110, a step is generated accordingly, and the amount of accumulated charge gradually increases by an amount corresponding to the irradiation. On the other hand, as shown in (B), when static electricity is generated at the timing indicated by reference numeral 112, the accumulated charge amount increases momentarily at each timing, but exhibits a unique behavior that decreases immediately thereafter. The present embodiment is characterized in that electrostatic noise is appropriately determined using the difference between the characteristic shown in (B) and the characteristic shown in (B), and the influence of the electrostatic noise is eliminated as much as possible. Is. Details thereof will be described later.

  Returning to FIG. 1, the ADC 32 that receives the output from the electrometer circuit 29 converts the input signal into a digital signal and supplies the digital signal to the processor 34 (measurement value). The sampling rate of the ADC 32 can be set as desired. For example, the sampling interval is 0.1 to 1.0 s, preferably 0.5 s. Of course, a slower display rate may be employed when displaying the display value after finely sampling.

  The processor 34 is configured by a microcomputer or the like, and applies a moving average process to measurement values input in time series order, and an LCD (Liquid Crystal Display) 36 using a moving average value as a result of the moving average process as a display value. Output to. The display value calculated as described above is displayed on the LCD 36, and the display value is expressed in units such as an air dose rate. In the present embodiment, when electrostatic noise occurs, a process of displaying the most likely past display value for the second waveform portion following the first waveform portion instead of the current display value is performed. This will be described in detail later with reference to FIG. 3 and the like, but the processor 34 analyzes the waveform after the moving average, replaces the display value as necessary, and as the raw data as necessary. The measured value is deleted. This is to prevent the influence of static noise from remaining in the moving average process after the generation of static noise, on the premise that the moving average process is performed on a plurality of measurement values over a certain period.

  Incidentally, the survey meter in the present embodiment is portable, but of course, the present invention can also be applied to a fixed installation type radiation measuring instrument.

  In FIG. 3, the functions of the processor 34 are shown as a block diagram. Each function shown in FIG. 3 is realized by a software operation in the processor 34. The measurement value memory 40 has a structure such as a ring buffer, for example, and stores a series of measurement value sequences from a current measurement value to a measurement value within a certain period in the past. The moving average processing unit 42 sets a moving average processing period from the present to a certain period going back to the past, and executes a moving average process (smoothing process) on a plurality of measured values within the moving average processing period. The current moving average is obtained. That is, a moving average value is obtained for each time. In this case, the moving average period is set up to a point where each measured value (or another calculated value based on it) falls within a certain dispersion value when looking back from the present to the past in the present embodiment. The moving average period is variable. For this, the method described in Patent Document 1 can be used. In a steady state, a relatively long moving average period is set, and a relatively short moving average period is set under a situation where it fluctuates drastically. In particular, when static noise suddenly occurs in a steady state, a relatively long moving average period is set as described above, so that the influence of the static noise remains for a considerably long time after the occurrence. Therefore, in the present embodiment, such a problem is prevented by the exclusion processing unit 52 described later. The moving average period may be fixedly set. Even when the moving average period is variably set, the moving average period may be set adaptively based on other criteria, instead of referring to the degree of variation of the measured value as in the present embodiment. .

  The moving average value memory 46 temporarily stores the moving average value. This is because an appropriate past moving average value is used as a current display value in a provisional display process or an alternative display process described later. Therefore, the moving average value memory 46 stores the moving average values for the necessary number retroactively from the current moving average value.

  In the normal display process, the display processing unit 44 outputs the current moving average value output from the moving average processing unit 42 as a display value as it is. On the other hand, a specific movement read from the moving average value memory 46 in place of the current moving average value is not displayed in the period corresponding to the second waveform portion corresponding to the second half portion of the electrostatic noise waveform. An average value (provisional moving average value or representative moving average value) is output.

  The waveform analysis unit 48 refers to the time-series moving average value output from the moving average processing unit 42 and recognizes a specific waveform corresponding to electrostatic noise. Specifically, in order to perform the calculation process simply, in the present embodiment, as will be described later, three detections of point A, point B, and point C are performed. A-1 point is also specified. The waveform analysis unit 48 includes a timer 50. For example, when the point B is not detected after a predetermined period after the point A is detected, the waveform analysis processing routine is reset. The same applies to the detection of the point C. If the point C cannot be detected after a certain period of time has elapsed after the detection of the point B, the waveform analysis processing routine is returned to the initial state. When the waveform analysis unit 48 detects the first waveform portion as the first half of the electrostatic noise waveform, specifically, when the points A and B described later are detected, the subsequent second waveform portion is In order to apply the temporary display process, control signals 54 and 57 are output to the display processing unit 44 and the moving average value memory 46, respectively. The control signal 54 is a signal for switching the display processing mode, and the control signal 57 is a signal for reading out the moving average value at point A-1 described later from the moving average value memory 46. Further, the waveform analysis unit 48 controls the control signal when the second waveform portion which is the second half portion is detected after the first waveform portion, specifically when the C point is detected after the B point. 56 is output to the exclusion processing unit 52.

  The exclusion processing unit 52 executes a process of deleting a series of measurement values within the period specified by the control signal 56 from the measurement value memory 40. Specifically, a plurality of measurement values from point A to point C are deleted from the measurement value sequence on the measurement value memory 40. It is also possible to insert a plurality of dummy data for the deletion period after deletion, and in that case, it may be possible to use an average value of measured values in a past fixed period as dummy data. In any case, by excluding a plurality of measured values within a period corresponding to such electrostatic noise, the target of the moving average process can be optimized after the exclusion, in other words, after the occurrence of electrostatic noise. It is possible to effectively prevent the influence from remaining in the moving average process.

  FIG. 4 is a conceptual diagram showing the operation of the configuration shown in FIG. Of course, the configuration shown in FIG. 3 and the operation shown in FIG. 4 are merely examples, and other configurations may be used.

  4A shows a measured value sequence stored in the measured value memory 40 shown in FIG. Further, (B) shows a moving average value sequence output from the moving average processing unit 42. Further, (C) shows a display value string displayed on the LCD 36 shown in FIG. As indicated by the time axis t, the right end of each column represents the current value. The processing time delay is ignored in FIG. As described above, the moving average value is obtained by processing a plurality of measurement values within a predetermined period from the present to the past, and the processing is executed at each time. Here, the points A, B, and C, which will be described later, are represented as symbols in the moving average value sequence, and the A-1 point immediately before the A point and the C + 1 point next to the C point are shown. Has been. The example shown in FIG. 4 represents immediately after the occurrence of electrostatic noise, and the moving average value at point C + 1 is displayed as a display value as it is.

  When the moving average value sequence is referred to by the waveform analysis unit described above, and the point B is detected subsequently to the point A, as shown by reference numeral 102, the displayed display value is the A− acquired in the past. A moving average value of one point is used. That is, point A is the initial point of electrostatic noise, and the moving average value at a point before that point is an appropriate value and continues to be displayed after point B. Incidentally, the moving average process itself is continuously executed even during the period, and the point C is detected by referring to the moving average value at each time point. When point C is detected, that is, when the end point of electrostatic noise is detected, a plurality of measured values corresponding to the period from point a to point c are deleted from the measured value sequence as indicated by reference numeral 104. . Here, a represents a measured value corresponding to point A, b represents a measured value corresponding to point B, and c represents a measured value corresponding to point C, but from a to c Multiple measurement values will be deleted at once. In addition, when calculating the moving average value at point C + 1, the moving average period 100 is set in a state where the time axis after measurement value exclusion is partially compressed as shown in FIG. A moving average process can be performed by selecting an appropriate measurement value group excluding the corresponding portion. Then, the moving average value obtained by such an appropriate moving average process is displayed next to the period indicated by reference numeral 102. This is repeated.

  In the example shown in FIG. 4, the period 104 from a to c in the measurement value sequence is an exclusion target. However, the exclusion target may be specified by widening or reducing the period 104 as a reference. Although the alternative display is performed from the moving average value immediately after the detection of the point B, the alternative display can be applied from the point of time when the moving average value of the point B is displayed in time. Further, from the temporal relationship, the moving average value of the point A-1 may be displayed as it is at the point C + 1, and the normal display may be applied from the next point C + 2. That is, the principle shown in FIG. 4 can be developed in various variations. In any case, it is desirable to prevent static noise from appearing as much as possible while giving priority to the display of the true signal in the display provided to the user. In addition, it is desirable to prevent the influence of electrostatic noise as much as possible in the moving average process.

  The above principle will be described in more detail with reference to FIGS. FIG. 5 shows the moving average value sequence as a waveform, and FIG. 6 shows the display value sequence as a waveform.

  In FIG. 5, the electrostatic noise waveform 200 can be roughly divided into a first waveform portion as the first half portion and a second waveform portion as the second half portion, and the first waveform portion has a form close to a true signal. However, the second waveform portion can be regarded as having a form inherent to electrostatic noise.

  In the present embodiment, the difference between two values (moving average values) adjacent to each other on the time axis is sequentially calculated, and when the difference exceeds a certain value (x), the point A is indicated by the excess point. Identified. This point A corresponds to the initial point. When point A is specified, point A-1 is specified as the immediately preceding point. The point A-1 corresponds to a reference point. Next, point B is identified. Specifically, the value of the reference point A-1 and the current value are sequentially compared, and when the difference exceeds a predetermined value −x in the minus direction, the point B is specified with that point. ing. Of course, x and -x may not have the same absolute value. After the point B is specified, the difference between the value of the reference point A-1 and the current value is sequentially calculated, and the point C is specified with a value where the difference exceeds y. This point C corresponds to the end point. y may be zero or a negative value.

  In the present embodiment, the value at the point A-1 is displayed as the display value from the point B to the point C by the provisional display process. That is, as apparent from the comparison between the waveform 200 and the waveform 202, the displayed display value sequence is flat after the point B, and the real-time display of the actual moving average value is resumed from the point C + 1. Will be. Therefore, since the display of the second waveform portion can be effectively suppressed, the influence of electrostatic noise can be reduced. Of course, it is desirable to cancel the first waveform portion as well. However, since the true signal may be excluded from the display if the cancellation is performed, the true signal is surely displayed in this embodiment. From this point of view, the first waveform portion is allowed to be displayed as it is. However, all the measured values (raw data) from point A to point C are deleted as described above in order to prevent the influence from remaining in the moving average process after the occurrence of electrostatic noise.

  Incidentally, the above x and y can be set as appropriate. For example, the values may be variably set according to the state of radiation. In addition, the electrostatic noise waveform may be analyzed more strictly by setting more points than the plurality of points described above as reference points. However, according to the above-described method, it is possible to recognize the static noise by detecting the three points A, B, and C, so that there is an advantage that quick processing can be achieved and the processing load can be reduced. .

  Next, an operation example of the radiation measuring apparatus according to the present embodiment will be described with reference to FIG.

  In S101, the difference between the previous moving average value and the current moving average value is sequentially calculated. In S102, it is determined whether or not the difference is + x or more. If the difference is + x or more, the current point is specified as point A in S103, and the previous point is specified as point A-1. Is done.

  In S104, the difference between the moving average value at point A-1 and the current moving average value is sequentially calculated. In S105, it is determined whether or not the difference is -x or less (x or more in the minus direction). Here, if the difference does not become x or more in the minus direction even after a predetermined time has elapsed, the process proceeds to S101. On the other hand, if the difference is not less than x in the minus direction within a certain period, point B is specified in S107. In conjunction with this, as shown in S113, an alternative process using the moving average value of point A-1 as the display value is started. This is performed from the point B + 1 in the present embodiment, but of course, the process may be executed from the point B.

  In S108, the difference between the moving average value at point A-1 and the current moving average value is calculated. In S109, it is determined whether or not the difference is greater than or equal to y. If the difference does not become greater than or equal to y even after a predetermined time has elapsed, the process proceeds from S110 to S101.

  On the other hand, if the difference is greater than or equal to y within a certain period, point C is specified in S111. When the point C is specified, the process of displaying the moving average value at the point A-1 in place of the current moving average value as shown in S114 ends. The process of S114 is also executed when it is determined in S110 that a certain time has elapsed. In S112, the measurement values (raw data) corresponding to points A to C are deleted from the target of the moving average process.

  The above steps S101, S104, S108 and the like are executed every time the current moving average value is obtained, which is according to the sampling rate. However, the difference may be calculated at a rate different from the sampling rate.

  According to this embodiment, the influence of static electricity can be excluded or reduced, and in particular, the influence of static electricity can be prevented from appearing as much as possible on the display device displayed in real time. Further, there is an advantage that the influence of static electricity can be prevented from remaining in the moving average process, and a highly reliable radiation measuring apparatus can be configured.

It is a conceptual diagram which shows suitable embodiment of the radiation measuring device which concerns on this invention. It is a figure which shows the time change of the electric charge stored in a capacitor. It is a block diagram for demonstrating the function of the processor shown in FIG. FIG. 4 is a principle explanatory diagram for explaining the operation of each configuration shown in FIG. 3. It is a figure which shows the waveform of a moving average value row | line | column. It is a figure which shows the waveform of a display value row | line | column. It is a flowchart which shows an example of operation | movement of the radiation measurement value shown in FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Ionization chamber part, 12 Signal calculating part, 29 Electrometer circuit, 40 Measurement value memory, 42 Moving average process part, 44 Display processing part, 46 Moving average value memory, 48 Waveform analysis part, 52 Exclusion process part

Claims (9)

A measurement value output means for outputting a measurement value at each time by measuring radiation;
Moving average processing means for obtaining a moving average value at each time by performing a moving average process on a plurality of measured values within the moving average period;
First waveform portion detection means for monitoring a moving average value at each time and detecting a first waveform portion in a specific waveform caused by static electricity;
Second waveform portion detecting means for sequentially monitoring the moving average value at each time and detecting a second waveform portion following the first waveform portion in the intrinsic waveform caused by static electricity;
When the second waveform portion is detected subsequent to the first waveform portion, an exclusion process for excluding a plurality of measurement values obtained within a period corresponding to the natural waveform from the target of subsequent moving average processing Exclusion processing means to be executed;
A radiation measuring instrument comprising: The radiation measuring instrument according to claim 1,
A normal display process for displaying the moving average value at each time in a normal period is executed, and the moving average value at each time in a period from when the first waveform portion is detected until the presence or absence of the second waveform portion is determined. A radiation measuring instrument comprising display processing means for executing provisional display processing for displaying a provisional moving average value instead. The radiation measuring instrument according to claim 1,
The first waveform portion is a rising portion in the intrinsic waveform caused by the static electricity,
The radiation measuring instrument according to claim 1, wherein the second waveform portion is a falling portion in the intrinsic waveform caused by the static electricity. The radiation measuring instrument according to claim 2, wherein
The provisional moving average value is based on a past moving average value before a characteristic waveform caused by the static electricity. The radiation measuring instrument according to claim 2, wherein
The display processing means ends the provisional display processing and returns to the normal display processing when the second waveform portion is not detected within a predetermined period after the first waveform portion. Radiation measuring instrument. The radiation measuring instrument according to claim 1,
The first waveform portion detecting means includes
Means for recognizing an initial point of the first waveform portion by comparing moving average values adjacent in time, and recognizing a reference point immediately before the initial point;
Means for recognizing the falling point of the first waveform portion by comparing the moving average value of the reference point and the moving average value at each time;
Including
The radiation measuring instrument according to claim 1, wherein when the initial point and the descending point are recognized, it is regarded as detection of the first waveform portion. The radiation measuring instrument according to claim 6.
The second waveform portion detecting means includes means for recognizing an end point of the second waveform portion by comparing the moving average value of the reference point and the moving average value at each time,
The radiation measuring instrument according to claim 1, wherein the second waveform portion is regarded as being detected when the end point is recognized within a certain period after the descending point. The radiation measuring instrument according to claim 7 , wherein
In the exclusion process, a plurality of measured values from the initial point to the end point are excluded from the moving average process. The radiation measuring instrument according to claim 7, wherein
The radiation measuring instrument, wherein a moving average value of the reference point is displayed instead of a moving average value at each time in a period from the detection of the descending point to the end point.

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