JP4746383B2 - Radiation measurement equipment - Google Patents

Description

  The present invention relates to a radiation measuring apparatus used for measuring radiation in a radioactive substance handling facility or the like.

  Many inventions have been made with respect to radiation measuring apparatuses used to measure radiation in radioactive material handling facilities or the like (see Patent Document 1), but typically has a configuration as shown in FIG. In other words, the conventional radiation measuring apparatus includes a radiation detector 1 and a measuring apparatus main body 7, the measuring apparatus main body 7 includes a counting circuit 2 and a controller 6, and the counting circuit 2 includes a counter 3 and a transmission circuit 4.

The radiation detector 1 generates an electric pulse or an optical pulse when radiation is incident. The electric pulse or the optical pulse is counted by the counter 3 with a predetermined peak value or more. This count value is input to the controller 6 as a communication packet such as TCP / IP or UDP / IP via the transmission circuit 4, and the controller 6 displays and records the measurement result.
JP 2004-3882 A

  The radiation measuring apparatus is calibrated every predetermined period. For example, in the case of a device that calibrates every week, if the instruction is shifted immediately after the end of calibration due to a device abnormality or the like, the abnormality cannot be corrected until the next week after calibration. And it is necessary to stop the measurement at the time of calibration, and during that time, it will be missing.

  The radiation measuring apparatus needs to perform processing before the counter digit overflows, but as the number of digits decreases, a higher sampling rate is required. For this reason, the load on the apparatus becomes high and the processing may not be able to catch up when the count is high. Also, when the counting circuit 2 fails, it is difficult to narrow down and specify the relevant part of the circuit, and it takes time to recover.

  In addition, there is duplication in order to improve the reliability of measuring equipment, but conventional duplication is a mechanism that switches from system to system, and the sound part included in the system separated from the measurement line due to failure is used effectively There is a problem that is not.

  Further, the communication between the counting circuit 2 and the controller 6 is required to be speeded up, and the networking is progressing. However, the communication packet 5 may be destroyed or lost due to a failure such as network congestion.

  An object of the present invention is to provide a radiation measurement apparatus that can confirm the soundness of a circuit while performing radiation measurement and does not cause missing measurement.

The radiation measurement apparatus of the present invention inputs a radiation detector for detecting radiation, a calibration signal generator for generating a calibration signal, a detector signal from the radiation detector, and a calibration signal from the calibration signal generator. A signal selection circuit for switching and outputting the detector signal and the calibration signal in a time-division manner during an abnormality diagnosis of the detector signal; and the detector signal and the calibration signal output from the signal selection circuit. A counter for counting, a transmission circuit for transmitting the count value counted by the counter, and a controller for receiving the count value from the transmission circuit and comparing the count value of the calibration signal with the frequency value of the calibration signal generator; It is set as the structure provided with.

  According to the present invention, it is possible to provide a radiation measurement apparatus that can confirm the soundness of a circuit while performing radiation measurement and does not cause missing measurement.

Hereinafter, radiation measuring apparatuses according to first to fifth embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
As shown in FIG. 1, the radiation measuring apparatus according to the present embodiment includes a radiation detector 1 and a measuring apparatus main body 7a. The measuring apparatus main body 7a includes a counting circuit 2a and a controller 6, and the counting circuit 2a includes a counter 3 and A transmission circuit 4, a calibration signal generator 8, and a signal selection circuit 9 are provided. The radiation measuring apparatus according to the present embodiment switches the signal selection circuit 9 in a time-sharing manner, thereby simultaneously counting the signal from the radiation detector 1 and the signal from the calibration signal generator 8 to perform abnormality diagnosis.

  In the abnormality diagnosis, first, the signal selection circuit 9 switches the signal of the radiation detector 1 with a time distribution of 99.9%, for example, and the signal of the calibration signal generator 8 with a time distribution of 0.1%. Simultaneously with the switching, the data of the counter 3 (detector signal value or calibration signal value) is transmitted to the controller 6 via the transmission circuit 4 as a communication packet 5 using the TCP / IP or UDP / IP protocol. The controller 6 determines whether or not the calibration signal value is the same frequency value as that of the calibration signal generator 8 among the received detector signal value and calibration signal value. Since the counter 3 is normal, the detector signal is processed as a normal value. If they are not equal, it is determined that the counting circuit 2a, particularly the counter 3, is out of order, and the detector signal value is also determined to be an abnormal value.

  The radiation measuring apparatus according to the present embodiment can check the soundness of the counting circuit 2a after the signal selection circuit 9 while counting the signal from the radiation detector 1, so that more reliable radiation measurement can be performed. It becomes possible. In addition, it is possible to calibrate the measuring instrument without stopping the radiation measurement. Since time division is performed for measurement and calibration, the actual measurement time is reduced. However, for example, if the radiation sampling time is 1 second and the time for measuring the calibration reference pulse is 0.001 seconds, there is no practical problem.

(Second Embodiment)
As shown in FIG. 2, the radiation measuring apparatus according to the present embodiment includes a radiation detector 1 and a measuring apparatus body 7b. The measuring apparatus body 7b includes a counting circuit 2b and a controller 6, and the counting circuit 2b includes a counter 3a, 3b, 3c, a transmission circuit 4, and frequency dividing circuits 10a, 10b. In the radiation measuring apparatus according to the present embodiment, the pulse signal from the radiation detector 1 is divided by the frequency dividing circuits 10a and 10b for each frequency and input to the counters 3a, 3b, and 3c.

  For example, the counting counters 3a, 3b, and 3c are counters of a maximum of 9 counts (overflow at the 10th count and return to 0), and the frequency dividing circuits 10a and 10b are final when the radiation detector 1 receives 524 counts. Specifically, 4 counts are input to the uppermost counter 3a (one digit), 2 counts are input to the intermediate counter 3b (tenth digit), and 5 counts are input to the lowermost counter 3c (hundred digit). Incidentally, the counter 3 can count only one digit 4 when there is no frequency dividing circuit as shown in FIG.

  Since the radiation measuring apparatus according to the present embodiment can count high-count pulses, the sampling cycle can be reduced to reduce the load on the counting circuit, which is equivalent to mounting a counter with a large number of digits. effective. Thus, although a counter having a large number of digits has a limit, the use of a frequency divider circuit can cope with an increase in the number of digits of the input signal within the range of the response time of the counting circuit.

(Third embodiment)
As shown in FIG. 3, the radiation measuring apparatus of the present embodiment includes a radiation detector 1 and a measuring apparatus main body 7c. The measuring apparatus main body 7c includes a counting circuit 2c and a controller 6, and the counting circuit 2c includes a counter 3a, 3b, 3c, a transmission circuit 4, calibration signal generators 8a, 8b, 8c, signal selection circuits 9a, 9b, 9c, and frequency dividing circuits 10a, 10b.

  In the radiation measuring apparatus of the present embodiment, the pulse signal from the radiation detector 1 is divided into frequencies for each frequency by the frequency dividing circuits 10a and 10b and input to the counters 3a, 3b and 3c. Then, the calibration signal generators 8a, 8b, 8c and the signal selection circuits 9a, 9b, 9c are controlled in a time-sharing manner to perform abnormality diagnosis for each of the counters 3a, 3b, 3c. The detection method of abnormality diagnosis is the same as that of the first embodiment, but the range can be expanded and abnormality detection can be performed for each of the counters 3a, 3b, 3c of each digit.

  Since the radiation measuring apparatus according to the present embodiment can perform abnormality diagnosis for each of the counting counters 3a, 3b, and 3c as described above, it is possible to easily narrow down a failure portion, and as a result, the measuring apparatus can be restored early. it can.

(Fourth embodiment)
As shown in FIG. 4, the radiation measuring apparatus according to the present embodiment includes counters 3a, 3b, 3c, calibration signal generators 8a, 8b, 8c, and signal selection circuits 9a, 9b, 9c, respectively, in the counting circuit 2d. Two systems of frequency division / calibration / counting units 12a and 12b including frequency dividing circuits 10a and 10b are provided.

  In the radiation measuring apparatus of this embodiment, the soundness of each counter 3a, 3b, 3c is confirmed for each system by the dual frequency dividing / calibrating / counting units 12a, 12b and the controller 6 in the counting circuit 2d. Instead of switching, it is possible to employ a healthy counter from the whole that is not trapped by the system.

  The method for detecting an abnormal circuit is the same as that in the first embodiment except that it is duplicated. As shown in FIG. 5, when the calibration value 2 of the a system (frequency division / calibration / counting unit 12a) is abnormal, it is determined that the detector value 2 is also abnormal, and the b system (frequency division / calibration / counting unit) Similarly in 12b), since the calibration value 3 is abnormal, it is determined that the detector value 3 is abnormal. In this case, since both ab systems are abnormal, the measurement function is stopped in the conventional switching method for each system, but in this embodiment, healthy detector values of each system are combined to obtain a normal detector value of 1. It is possible to continue measurement at ~ 3. In this way, if the 3 digit of the a system fails, it can be supplemented by the 3 digit data of the b system, and even if the 4 digit of the b system fails, it can be supplemented by the 4 digits of the a system. ) Will improve.

  In the radiation measurement apparatus according to the present embodiment, it is possible to employ a healthy counter from within the entire system, so that the apparatus operates normally even if a counter of a different type for each system fails. Reliability can be improved.

(Fifth embodiment)
As shown in FIG. 6, the radiation measuring apparatus of the present embodiment includes a radiation detector 1 and a measuring apparatus body 7e. The measuring apparatus body 7e includes a counting circuit 2e and a controller 6, and the counting circuit 2e includes two systems. Frequency division / calibration / counting units 12a and 12b and a transmission circuit 4a are provided. The frequency division / calibration / counting units 12a and 12b are counters 3a, 3b and 3c, calibration signal generators 8a, 8b and 8c, and a signal selection circuit, respectively. 9a, 9b, 9c and frequency dividing circuits 10a, 10b.

  In the radiation measuring apparatus of the present embodiment, when the measurement data is sent from the counting circuit 2e to the controller 6, the data of the counters 3a, 3b, 3c are individually sent to each port of the controller 6 as they are.

  The transmission circuit 4a adds a time stamp to the transmission data transmitted from the counters 3a, 3b, 3c, and transmits it to each port of the controller 6 for each measurement data (digits). The received controller 6 confirms the time stamp and associates the received data individually. At this time, the abnormal value and missing data are compensated with the digits of normal data of other systems.

  In the network, the transmitted packet may be lost or destroyed due to the load of the network itself and the load of the reception port. In this case, if the transmission data is set to one packet, not all data reaches the receiving side. However, the effect of reducing the risk and improving the reliability can be obtained by transmitting the data individually (a plurality of packets). Even if a problem occurs in a part of transmission, it is possible to restore a part of the data of another system that is duplicated.

The block diagram which shows the structure of the radiation measuring device of the 1st Embodiment of this invention. The block diagram which shows the structure of the radiation measuring device of the 2nd Embodiment of this invention. The block diagram which shows the structure of the radiation measuring device of the 3rd Embodiment of this invention. The block diagram which shows the structure of the radiation measuring device of the 4th Embodiment of this invention. The figure explaining operation | movement of the radiation measuring device of the 4th Embodiment of this invention. The block diagram which shows the structure of the radiation measuring device of the 5th Embodiment of this invention. The block diagram which shows the structure of the conventional radiation measuring device.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Radiation detector, 2, 2a, 2b, 2c, 2d, 2e ... Count circuit, 3, 3a, 3b, 3c ... Counter, 4, 4a ... Transmission circuit, 5 ... Communication packet, 6 ... Controller, 7, 7a , 7b, 7c, 7d, 7e ... measuring device main body, 8, 8a, 8b, 8c ... calibration signal generator, 9, 9a, 9b, 9c ... signal selection circuit, 10a, 10b ... frequency dividing circuit, 12a, 12b ... Divider / calibrator / counter.

Claims (1)

A radiation detector for detecting radiation, a calibration signal generator for generating a calibration signal, a detector signal from the radiation detector, and a calibration signal from the calibration signal generator are input, and the detector signal and the calibration are input. a signal, a counter for counting a signal selection circuit for switching and outputting in a time division, and the detector signal and the calibration signals output from said signal selection circuit in the abnormality diagnosis of the detector signal, in said counter A transmission circuit that transmits the counted value, and a controller that receives the count value from the transmission circuit and compares the count value of the calibration signal with the frequency value of the calibration signal generator. A radiation measurement device.

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