JP2009063351A - Radiation monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten the reset time that extends from test indication value to background indication value. <P>SOLUTION: This radiation monitoring device is equipped with a detector 11 for detecting radiation, and outputting a signal pulse as its output; a test pulse generation part 2 for outputting a test pulse; and a measuring part 12 for inputting the signal pulse from the detector, when a changeover switch is in a normal mode, and inputting the test pulse from the test pulse generation part, when the changeover switch is in a test mode, via the changeover switch 121 switched and controlled between the normal mode and the test mode. In the device, radiation is monitored by operation of the measuring part in the normal mode, and operation test is performed by operation of the measuring part in the test mode. The measuring part outputs an indication value, at a quicker time constant than the case in the normal mode during a prescribed period, when the mode is switched over from the test mode to the normal mode. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a radiation monitoring apparatus used for release management, radiation management, etc. of a nuclear reactor facility, a spent fuel reprocessing facility, and the like.

A radiation monitoring device used in a nuclear reactor facility, a spent fuel reprocessing facility, or the like includes a detector that detects radiation and outputs a signal pulse, and a measurement unit that inputs the signal pulse and measures a radiation dose. A multi-channel radiation monitor, a test signal generator for inputting a test signal to each radiation monitor, and a controller for controlling the test signal generator and the radiation monitor. The controller operates an input selector switch of the measurement unit. Then, a simulated pulse signal is input from the test signal generation unit to the measurement unit, and the instruction response is checked to confirm the soundness of each radiation monitor.
Each radiation monitor that constitutes the radiation monitoring device is set to a high warning at a radiation dose level higher than the normal background level, and a high warning is given to the radiation rate in the management area of the facility or an abnormality in the radioactivity of the process system. It is a system that sends out and informs the operator, and automatically performs necessary system isolation.
In addition, a low alarm is set at a radiation dose level lower than the normal background level, and a low alarm is issued to notify the operator of a loss of the detector signal or a decrease in the repetition frequency of the detector signal due to a failure of the radiation monitor. Like to do.
The accuracy of the above instruction response and the soundness confirmation of the alarm operation are performed by inputting a test signal to the measurement unit, and the control unit controls the test signal generation unit according to the test item and the test content. The test signal repetition frequency is changed stepwise or ramped.
During the test period, the alarm can be blocked before the start of the test and the block can be released after the end of the test so that the high and low alarms are not output from the radiation monitoring apparatus to the outside. These operations are performed manually, and an alarm is output during the test while the alarm is blocked. When the test mode is selected with the input selector switch, an alarm during testing is automatically output, and the indication value is marked with an unreliable mark.

On the other hand, since the radiation dose measured by the radiation monitor fluctuates statistically, the time constant is controlled based on the count rate so that the standard deviation is constant, and the measurement range is covered and the specified accuracy is maintained. is doing.
In addition, the measurement unit is required to measure over a wide range of repetition frequencies from about 0.01 cps to about 10 ⁶ cps, and in order to eliminate discontinuities associated with range switching, the wide range can be switched without range switching. Count rate measurement is performed using an up / down counter capable of high-speed operation. This measuring method reads the integrated value of the difference between the addition input and the subtraction input at a constant period and calculates the count rate. In particular, this measurement method is characterized in that it can accurately measure even a high count rate. The addition input is a signal pulse obtained by discriminating and removing noise from the detector signal input from the detector to the measuring unit, and the subtraction input is a digital frequency synthesized from the clock pulse of the crystal oscillator based on the integrated value. This is a frequency feedback pulse.

  Count rate measurement using an up / down counter responds with a time constant, so an input / output test that checks the output accuracy by inputting a test signal for each card and an alarm that checks the alarm operation by inputting a test signal The test takes time. Therefore, test signal input is achieved by automatically and optimally combining the test signal that has been changed stepwise and the ramp shape, especially by optimizing the magnitude of the step change and the duration of the step. A device has been devised to shorten the response time of the counting rate for. (See Patent Document 1)

Japanese Patent No. 3749338 (FIGS. 1 to 3 and its description)

  The conventional radiation measurement device is configured as described above, and the test time is shortened by devising the method of inputting the test signal, but most channels are in continuous measurement while the facility is in operation, There are channels that require continuous operation even during the facility inspection period, and in order to further shorten the missing measurement and further reduce the inspection cost, further reductions in test time and automation were issues.

  The present invention has been made in view of the above-described circumstances, and an object thereof is to shorten the return time from the test instruction value to the background background instruction value.

  The radiation monitoring apparatus according to the present invention includes a detector that detects radiation and outputs a signal pulse as an output thereof, a test pulse generator that outputs a test pulse, and a changeover switch that is controlled to switch between a normal mode and a test mode. And a measuring unit for inputting the signal pulse from the detector when the changeover switch is in the normal mode and for inputting a test pulse from the test pulse generating unit when the changeover switch is in the test mode. A radiation monitoring apparatus that monitors radiation by the operation of the measurement unit and performs an operation test by the operation of the measurement unit in the test mode, wherein the measurement unit is switched from the test mode to the normal mode. During the specified period, the indicated value is output with a faster time constant than in the normal mode. It is.

  According to the present invention, the change-over switch is connected via a detector that detects radiation and outputs a signal pulse as an output thereof, a test pulse generator that outputs a test pulse, and a change-over switch that is controlled to switch between a normal mode and a test mode. A measurement unit that inputs the signal pulse from the detector in the normal mode and inputs a test pulse from the test pulse generation unit when the changeover switch is in the test mode; A radiation monitoring apparatus for monitoring radiation by operation and performing an operation test by the operation of the measurement unit in the test mode, wherein the measurement unit is switched between the test mode and the normal mode for a predetermined period of time. Since the indicated value is output with a faster time constant than in the normal mode, the test indicated value Tsu can significantly reduce the recovery time to click Grau background readings, an effect that can shorten the measurement missing by the test time.

Embodiment 1 FIG.
Embodiment 1 of the present invention will be described below with reference to FIGS. FIG. 1 is a block diagram illustrating an example of a radiation monitoring apparatus that is also a radiation measuring apparatus, FIG. 2 is a diagram illustrating an example of an instruction response characteristic when switching from a test mode to a normal mode, and FIG. 3 is a radiation monitoring of FIG. It is a flowchart which shows an example of the procedure of the calculation in the measurement part in an apparatus.

  In FIG. 1, the radiation monitoring apparatus includes a radiation monitor 1, a test pulse generator 2, and a controller 3.

  The radiation monitor 1 measures the radiation to be measured during normal monitoring, inputs a test pulse from the test pulse generator 2 during a test, and the controller 3 switches the input and time constant of the radiation monitor 1 to An operation test such as an alarm test and an input / output test is performed by changing the repetition frequency of the test signal of the test pulse generator 2 in a step shape or a ramp shape.

  The radiation monitor 1 includes a detector 11 and a measurement unit 12.

  The detector 11 detects radiation and outputs a signal pulse, and the measurement unit 12 inputs the signal pulse output from the detector 11 and measures the radiation dose. The control unit 3 inputs the output of the measurement unit 12 during the test period, determines the test result, and advances the test sequentially in a predetermined procedure while talking with the measurement unit 12.

  The measurement unit 12 includes an input selector switch 121, a pulse amplifier 122, a pulse height discriminator 123, an up / down counter 124, a frequency synthesis circuit 125, an integration control circuit 126, an arithmetic unit 127, an output terminal 128, and a memory 129. Yes.

  The input change-over switch 121 receives a signal pulse from the detector 11 and a test pulse from the test pulse generator 2 and performs a switching operation in accordance with a control command from the controller 3, so that the detector The signal pulse from 11 and the test pulse from the test pulse generator 2 are switched and output.

  The pulse amplifier 122 amplifies the signal pulse switched and output by the input selector switch 121.

  The wave height discriminator 123 discriminates that the voltage level of the signal pulse amplified by the pulse amplifier 122 is equal to or higher than a predetermined level, or discriminates that it is within an allowable range, and outputs a digital pulse.

  The up / down counter 124 inputs the digital pulse output from the pulse height discriminator 123 to the addition input 1241, inputs the digital pulse output from the frequency synthesis circuit 125 to the subtraction input 1242, and the integrated value of the result Output M.

  The integration control circuit 126 controls the up / down counter 124 so that the addition input 1241 and the subtraction input 1242 of the up / down counter 124 are counted based on the standard deviation σ.

The frequency synthesizing circuit 125 inputs the integrated value M output from the up / down counter 124, repeatedly converts it to the frequency F _B (M), and inputs it to the subtraction input 1242 of the up / down counter 124.

  The computing unit 127 receives the integrated value M output from the up / down counter 124, obtains a count rate n based on the integrated value M, performs engineering value conversion and alarm determination based on the count rate n, and performs radiation. The measured value and the alarm are output from the output terminal 128, respectively.

  The memory 129 stores calculation procedures and set values necessary for the calculation by the calculator 127 and stores calculation results.

Since the counting rate due to radiation fluctuates statistically, in order to measure with a predetermined accuracy, the time constant τ is controlled based on the counting rate n so that the standard deviation σ is constant as in the following equation: Yes.
σ = 1 / (2nτ) ^1/2 ... (1)
τ = 1 / (2nσ ² ) (2)

The addition input 1241 of the up / down counter 124 is a digital pulse output from the pulse height discriminator 123 corresponding to a signal pulse from which noise has been removed, and the subtraction input 1242 is a crystal oscillator (see FIG. This is a digital pulse output from the frequency synthesizing circuit 125, which is frequency synthesized from a clock pulse (not shown). In an equilibrium state, the repetition frequency F _IN of the addition input 1241 of the up / down counter 124 is equal to the count rate n obtained by the calculator 127 and the repetition frequency F _B (M) of the subtraction input, and the standard deviation σ and Based on the integrated value M, the following equation is calculated. F _B (M) and n respond by following the first-order lag of the time constant (τ) so as to balance with F _IN as in the following equation.
F _IN = F _B (M) = n = e ^γM = 2 ^{γM / ln2} (3)
γ = 2σ ² = 1 / (nτ) = 2 ^−λ ln2 (4)
λ = 11−α (5)

Assuming that λ is 11, 9, 7, 5 in the above equation (4), the standard deviations σ are 1.3%, 2.6%, 5.2%, and 10.4%, respectively, as shown in the above equation (1). When lambda above (4) is based on the time of 11, lambda is when 9,7,5, gamma ² times respectively 2, 2 ^four times, is 2 ⁶ times, as described above (1) 2 ¹ times the standard deviation σ, respectively, 2 ^doubles, becomes 2 ³ times, the (2), respectively 2 ^-2 times the time constant, as in equation 2 ^-4 times, a ^2-6 fold.

When n as shown in equation (3) is in the 2 ^alpha double the γ in a constant state, M is equilibrated with ^2-.alpha. times. n in a certain state, to ensure that M does not change even by changing the γ, said up-down counter 124 After the γ to 2 ^alpha times may be counted by weighting of one pulse 2 ^alpha times. That is, when the digital pulse output to the adder input 1241 from the pulse height discriminator 123 of the up-down counter 124 is one input, M is to be added counted by 2 ^alpha. On the other hand, when the digital pulse output to the subtraction input 1242 of the up-down counter 124 from the frequency synthesizer circuit 125 is one input, M is to be subtracted counted by 2 ^alpha. Results the cumulative value M as will integration value a value obtained by multiplying the 2 ^alpha to N of the difference subtraction counting and addition count. Here, α is 0 or a positive integer. When λ is 11, 9, 7, 5 as shown in the above equation (5), 0, 2, 4, 6 are respectively given as α. For example, when λ is 11, M is added to or subtracted from one pulse input, and M and N are equal. When λ is 9, four pulses are added or subtracted for one pulse input.

Thus, the (3) changing the 2 ^alpha double the γ In the equation is equivalent to changing the weighting count to 2 ^alpha times, counting index n, weighted result of the cumulative value to 2α times Based on M and γ corresponding to the reference λ = 11 (α = 0), it is obtained by the equation (3). In this way, the integration control circuit 126 can easily change the standard deviation σ by controlling the weighting of the count of the up / down counter 124. Further, since the integrated value M does not change even if the standard deviation σ is changed, the response characteristic can be changed without changing the center value of the instruction during measurement. The above equation (3) expresses the output pulse of the frequency synthesizer 125 as an approximate expression according to the convenience of the circuit or the arithmetic processing of the arithmetic unit 127, and as a special example, it is expressed as a polygonal line approximation. Also good.

  The measuring unit 12 switches the change-over switch 121 from a signal pulse to a test pulse in response to an input switching command from the control unit 3. The test pulse generator 2 outputs a test pulse having a repetition frequency according to the request from the controller 3 to the measuring unit 12.

When the test mode ends and the test mode is switched to the normal mode, the input selector switch 121 switches from the test pulse input to the signal pulse input, and the standard deviation σ of the arithmetic unit 127 corresponds to the normal time constant τ _s . switches to the standard deviation sigma _f from the standard deviation sigma _s corresponding to constant tau _f time faster than the normal time constant tau _s of the return to the standard deviation sigma _s corresponding to the normal time constant tau _s After a predetermined time period ends To do.

For the period T of the time constant τ _f faster than the normal time constant τ _s, the normal mode instruction value n ₁ immediately before switching from the normal mode to the test mode, and the test mode instruction n ₂ immediately before switching from the test mode to the normal mode, , Τ _s standard deviation σ _f is obtained by the following equation. However, the predetermined time period ends when, for example, an instruction value in the return process and when it reaches within the range of statistical variation of the normal mode instruction value n _1, and a within the range of the statistical variation example 3 [sigma] _s To do.
When n ₂ / n ₁ > (1 + 3σ _s ): T = 1 / {2n ₁ (σ _f ) ² } ln [{1 / (3σ _s ) +1} · (1−n ₁ / n ₂ )] ··・ (6)
When n ₂ / n ₁ > (1−3σ _s ): T = 1 / {2n ₁ (σ _f ) ² } ln [{1 / (3σ _s ) −1} · (n ₁ / n ₂ −1) ] ... (7)
When (1−3σ _s ) ≦ n ₂ / n ₁ ≦ (1 + 3σ _s ): T = calculation cycle (8)

FIG. 2 shows the instruction response characteristics when the test mode according to the first embodiment is switched back to the normal mode. When the input changeover switch 121 operates and the test pulse input is switched to the signal pulse input. and returns to the background instruction c from the final instruction a test mode via the transient b _f a solid line. The dotted line b _s shows the conventional transient change, and b _s changes with the time constant τ _s in the normal mode, whereas b _f changes with the fast time constant τ _f above. The time until returning to the background instruction c is shortened.

The time T required for return is obtained by equation (6) or (7) or (8) .For example, in the test mode, the final indication value n ₂ is 1000 cpm, the background indication value n ₁ is 50 cpm, and the standard deviation is to 2.6%, when the standard deviation of the time of the fast time constant tau _f is 10.5% of the conventional had returned to background instruction in about 37 minutes, about when to the fast time constant tau _f 2 The time required for returning to the background instruction can be greatly reduced. T = calculation cycle in equation (8) indicates that the normal mode is restored in the next calculation cycle. In the expression (6) or (7), the time T required for recovery may be p times faster than the fast time constant, for example 2 to 4 times, and may be operated in a simple form as in the following expression.
T = p × 1 / {2n ₁ (σ _f ) ² } (9)

FIG. 3 is a flowchart showing a calculation procedure according to the first embodiment. In the normal mode, the calculator 127 reads the integrated value M (current) of the current calculation cycle of the up / down counter 124 operating at the standard deviation σ _s and the control command of the control unit 3 (step ST1). A count rate n (current) is obtained based on the integrated value M, a predetermined calculation is executed and output (step ST2), and the presence or absence of a test start command from the control unit 3 is confirmed (step ST3). If there is no (No), the process returns to step ST1 in the next calculation cycle. When there is a test start command from the control unit 3 (Yes in step ST3), the arithmetic unit 127 switches the input of the input changeover switch 121 from a signal pulse to a test pulse (step ST4), and a test is in progress. An alarm is output (step ST5), and the test mode after step ST6 is entered in the next calculation cycle.

In the test mode, the calculator 127 reads the integrated value M (current) of the current calculation cycle of the up / down counter 124 operating at the standard deviation σ _s and the control command of the control unit 3 (step ST6). A count rate n (current) is obtained based on the integrated value M, a predetermined calculation is executed and output (step ST7), and the presence or absence of a test end command from the control unit 3 is confirmed (step ST8). If there is no (No), the process returns to step ST6 in the next calculation cycle. When there is a test end command from the control unit 3 (Yes in step ST8), the arithmetic unit 127 switches the input changeover switch 121 from the test pulse to the signal pulse (step ST9). The standard deviation σ is switched from σ _s to σ _f (step ST10), and a transition period from the test mode to the normal mode is started in the next calculation cycle.

In the transition period, the calculator 127 reads the integrated value M (current) of the current calculation cycle of the up / down counter 124 operating at the standard deviation σ _f (step ST11), and counts based on the integrated value M. The rate n (current) is obtained, a predetermined calculation is executed and output (step ST12), and it is confirmed whether the instruction n has returned to (1−3σ _s ) ≦ n / n ₁ ≦ (1 + 3σ _s ) ( In step ST13), when the return is made (in the case of Yes), the standard deviation σ is switched back from σ _f to σ _s (step ST14), the alarm during the test is reset (step ST15), and the next calculation cycle returns to step ST1. Return. If the instruction n has not returned to (1−3σ _s ) ≦ n / n ₁ ≦ (1 + 3σ _s ) (No in step ST13), check whether the time T in equation (6) has elapsed. (Step ST16) When the time T has elapsed (in the case of Yes), the process proceeds to step ST14 in the next calculation cycle, and when the time T has not elapsed (in the case of No), the process returns to step ST11 in the next cycle. The measurement unit 12 can be automatically blocked so that a high alarm and a low alarm are not output to the outside of the radiation monitoring apparatus during a period in which an alarm during a test is being output.

  As described above, the control unit 3 switches the input signal of the measurement unit 12, inputs a signal pulse in the normal mode, and inputs a test pulse in the test mode, ends the test mode, and switches to the normal mode. After returning, the measurement unit 12 calculates the count rate with the standard deviation of the time constant faster than the normal time constant, and when the instruction returns to the predetermined background range or when the predetermined time has elapsed, the normal time constant Since the standard deviation is restored, the return time from the test indication value to the background indication value can be greatly shortened, and the missing time due to the test can be shortened.

  Further, the control unit 3 sets the fast time constant based on the normal mode instruction value immediately before switching to the test mode, the test mode instruction value immediately before switching from the test mode to the normal mode, and the standard deviation corresponding to the fast time constant. Since the corresponding standard deviation period is determined, the background indication value can be restored in the shortest time.

  In addition, the measuring unit 12 automatically issues a test-in-progress alarm to notify that the test is in progress during the test mode and during the standard deviation corresponding to the fast time constant after switching from the test mode to the normal mode. During the period when the alarm is being sent during the test, the alarm block is set to automatically turn off so that the high alarm or low alarm is not output outside the radiation monitor. It is possible to reliably prevent the false alarm from being output.

  In addition, since a procedure for checking whether the time T in Equation (6) has elapsed, even if the background fluctuates during the test, it can automatically return to the normal time constant, and a highly reliable device Can provide.

  As described above, the first embodiment is a detector that detects radiation and outputs a signal pulse as its output, a test pulse generator that outputs a test pulse, and switching that is controlled to be switched between a normal mode and a test mode. A measuring unit for inputting the signal pulse from the detector when the change-over switch is in a normal mode via the switch, and for inputting a test pulse from the test pulse generation unit when the change-over switch is in a test mode; A radiation monitoring apparatus for monitoring radiation by the operation of the measurement unit in the mode and performing an operation test by the operation of the measurement unit in the test mode, wherein the measurement unit changes from the test mode to the normal mode. When switched, the indicated value is output for a predetermined period with a faster time constant than in the normal mode. A radiation monitoring device that detects radiation and outputs a signal pulse; a radiation monitor including a measurement unit that receives the signal pulse and measures a radiation dose; and inputs a test pulse to the radiation monitor A test pulse generator; and a control unit for controlling the test pulse generator and the radiation monitor. The measuring unit has a changeover switch at an input end thereof. The control unit sets the changeover switch to a normal mode and a test mode. When the normal mode is selected, the signal pulse is input to the measurement unit and the test pulse is input to the measurement unit. During the period, the measurement unit responds and outputs the indicated value with a faster time constant than in the normal mode. The radiation monitoring apparatus is characterized by returning to the normal time constant in the normal mode and outputting the indicated value in response to the normal mode, and in the radiation monitoring apparatus, the control unit is configured to start from the normal mode. Based on the indication value in the normal mode immediately before switching to the test mode, the indication value in the test mode immediately before switching from the test mode to the normal mode, and the fast time constant, Furthermore, in such a radiation monitoring apparatus, the measurement unit is under test during a period of the test mode and a period of a fast time constant after switching from the test mode to the normal mode. During the test, an alarm is sent to inform the fact that the alarm is being sent. The alarm block is automatically set so that a high alarm or low alarm is not output to the outside. The return time from the test indication value to the background indicator value can be greatly shortened, and the missing time due to the test can be shortened. .

Embodiment 2. FIG.
Hereinafter, Embodiment 2 of the present invention will be described with reference to FIG. 4 showing an example of the relationship between the test pulse repetition frequency input and the count rate instruction response in the low alarm test.

As shown in FIG. 4, in the test for confirming the low alarm operation at the low alarm set point d set to a level lower than the background instruction c, the test signal is received by the low alarm test command from the control unit 3. The generator 2 outputs a test pulse having a stepped repetition frequency e1, and the measuring unit 12 inputs the test pulse and switches the standard deviation σ from σ _s to σ _f and indicates with a time constant faster than the normal mode. When the value g _f is responded and the predetermined set value h in the process of reaching the low alarm set value is passed, the test signal generator 2 outputs a test pulse having a ramp-like repetition frequency e2, and the measuring unit 12 When the test pulse is input and the standard deviation σ is switched back from σ _f to σ _s , the indicated value g _s is responded with the time constant of the normal mode, and when the indicated value reaches the low alarm set value and an alarm is issued. So At this time, the instruction value g _s and the test pulse repetition frequency _FIN are held.

For example, in the low alarm test, if the input is changed stepwise from the background indication c = 50 cpm to 1 cpm, the normal mode standard deviation σ _s = 2.6% would take about 1 hour to send the low alarm. By switching to the standard deviation σ ₁ = 10.5%, it can be shortened to about 4 minutes. Although the above has been described with reference to the example of the low alarm, the test time can be shortened similarly for the high alarm when the high alarm set point is relatively low.

  As described above, since the response when inputting a test signal with a stepped repetition frequency in the alarm test is made to respond to the indicated value with a time constant faster than the normal mode by switching the standard deviation, the alarm test operation Test time can be greatly reduced.

  Further, when the indicated value reaches the alarm set value and the alarm is transmitted, the repetition frequency FIN of the test signal of the test signal generator 2 is held so that the integrated value M of the up / down counter 124 does not overrun. Therefore, there is an effect that the return time to the background instruction value can be shortened.

As described above, the second embodiment includes a detector that detects radiation and outputs a signal pulse, a radiation monitor that includes the measurement unit that receives the signal pulse and measures a radiation dose, and tests the radiation monitor. A test pulse generator for inputting a pulse; and a control unit for controlling the test signal generator and the radiation monitor. The measuring unit has a change-over switch at an input end, and the control unit sets the change-over switch to a normal mode. And test mode, and in the normal mode, a signal pulse is input to the measurement unit and a test pulse is input to the measurement unit to check the alarm operation. When a test pulse with a stepped repetition frequency is input in the test, the measurement unit responds with the indicated value with a faster time constant than in the normal mode. When the output exceeds the specified value in the process of reaching the low alarm set value, a test pulse with a ramp-like repetition frequency is input and the indicated value is responded with the same time constant as in the normal mode. A radiation monitoring apparatus that holds an instruction value when an alarm is transmitted when the alarm setting value is reached, and in the radiation monitoring apparatus, the test pulse generation unit is configured such that the instruction value reaches the alarm setting value in the measurement unit. when the alert Te, is to hold the repetition frequency F _iN of the test signal at that time.

Embodiment 3 FIG.
The third embodiment of the present invention will be described below with reference to FIG. 5 which is a block diagram showing another example of a radiation monitoring apparatus that is also a radiation measuring apparatus.

  In the first embodiment and the second embodiment described above, the case where the radiation monitor 1 has one channel has been exemplified. However, in the present third embodiment, as shown in FIG. Of the radiation monitors 1a, 1b,..., And the control unit 3 performs a plurality of channel tests simultaneously, that is, a plurality of radiation monitors 1a, 1b,. Since the measurement unit is provided with a plurality of channels and the test of the plurality of channels is performed by a common control unit, the test time of the radiation monitoring apparatus can be greatly shortened.

  In addition, in each figure, the same code | symbol shows the same or an equivalent part.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows Embodiment 1 of this invention, and is a block diagram which shows an example of the radiation monitoring apparatus which is also a radiation measuring apparatus. It is a figure which shows Embodiment 1 of this invention, and is a diagram which shows an example of the instruction | indication response characteristic when it switches back from a test mode to a normal mode. It is a figure which shows Embodiment 1 of this invention, and is a flowchart which shows an example of the procedure of the calculation in the measurement part in the radiation monitoring apparatus of FIG. It is a figure which shows Embodiment 2 of this invention, and is a diagram which shows an example of the relationship between the repetition frequency input of the test pulse at the time of a low alarm test, and a count rate instruction | indication response. It is a figure which shows Embodiment 3 of this invention, and is a block diagram which shows the other example of the radiation monitoring apparatus which is also a radiation measurement apparatus.

Explanation of symbols

1,1a, 1b radiation monitor,
11 detector,
12 measuring section,
121 selector switch,
122 pulse amplifier,
123 wave height discriminator,
124 up / down counter,
1241 Addition input,
1242 Subtract input,
125 frequency synthesis circuit,
126 integration control circuit,
127 calculator,
128 output terminals,
129 memory,
2 Test signal generator,
3 Control unit.

Claims (7)

  When the changeover switch is in normal mode via a detector that detects radiation and outputs a signal pulse as its output, a test pulse generator that outputs a test pulse, and a changeover switch that is controlled to switch between normal mode and test mode And a measurement unit for inputting the signal pulse from the detector and inputting the test pulse from the test pulse generation unit when the changeover switch is in the test mode, and radiation is generated by the operation of the measurement unit in the normal mode. A radiation monitoring apparatus for monitoring and performing an operation test by the operation of the measurement unit in the test mode, wherein the measurement unit is in the normal mode for a predetermined period when the test mode is switched to the normal mode. Radiation monitoring device that outputs the indicated value with a faster time constant. A detector that detects radiation and outputs a signal pulse, a radiation monitor including a measurement unit that receives the signal pulse and measures a radiation dose, a test pulse generator that inputs a test pulse to the radiation monitor, and the test A control unit for controlling the pulse generation unit and the radiation monitor, the measurement unit having a change-over switch at an input end thereof, and the control unit controls the change-over switch between a normal mode and a test mode; When in the mode, the signal pulse is input to the measurement unit in the test mode, and when the test mode ends and switches to the normal mode, the measurement unit The indicated value is responded and output with a faster time constant than in the normal mode, and when the predetermined period is over, the normal mode is output. The radiation monitoring device and outputs and returns to the normal time constant by the response an indication of the time.   3. The radiation monitoring apparatus according to claim 1, wherein the control unit includes an instruction value in the normal mode immediately before switching from the normal mode to the test mode, and immediately before switching from the test mode to the normal mode. A radiation monitoring apparatus characterized in that a period of the fast time constant is determined based on the indicated value in the test mode and the fast time constant.   3. The radiation monitoring apparatus according to claim 1, wherein the measurement unit is performing a test during the test mode and during a fast time constant after switching from the test mode to the normal mode. During the test, the alarm block is automatically set so that the high alarm or the low alarm is not output to the outside of the radiation monitoring apparatus. Radiation monitoring device.   A detector that detects radiation and outputs a signal pulse, a radiation monitor including a measurement unit that receives the signal pulse and measures a radiation dose, a test pulse generator that inputs a test pulse to the radiation monitor, and the test A control unit for controlling the signal generation unit and the radiation monitor; the measurement unit includes a changeover switch at an input end; the control unit controls the changeover switch between a normal mode and a test mode; and the normal mode In the test mode, the test pulse is input to the measurement unit to check the alarm operation, and in the test to check the alarm operation, a test pulse with a stepped repetition frequency is applied. Once input, the measurement unit responds and outputs the indicated value with a time constant faster than the normal mode, and reaches the low alarm set value. When the specified indication value is exceeded, a test pulse with a ramp-like repetition frequency is input, and the indication value is returned with the same time constant as in the normal mode, and the indication value reaches the low alarm setting value and an alarm is transmitted. A radiation monitoring apparatus characterized in that the indicated value is held. The radiation monitoring device according to claim 5, the test pulse generator, when the indicated value in the measuring unit transmits an alarm reaches the alarm set value, to hold a repetition frequency F _IN of the test signal at that time A radiation monitoring apparatus characterized by.   The radiation monitoring apparatus according to claim 1, wherein the measurement unit includes a plurality of channels, and a test of the plurality of channels is performed by a common control unit.

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