JPS58223776A - Radiation monitoring device - Google Patents

Abstract

PURPOSE:To improve measurement precision and stability and improve a monitoring function, and to reduce the cost of cables, by measuring a radiation level digitally at a radiation measuring terminal station and transmitting the measurement result to a central monitor station in the form of a digital signal. CONSTITUTION:A dose in a radiation atmosphere is detected by a radiation detector 1 at the radiation measuring terminal station 31 and detection pulse are measured by a processing part 33 for a specific time to send the result to a processor 32. The processor 32 converts the counted value into a dose rate, which is stored in a memory 36. A transmission control part 35 sends an up-to- date dose rate to the central monitor station 41, which stores the input value in a memory 57 and displays and records it; and a processor 56 calculates an integral dose in every radiation atmosphere and an average value of the dose rate within a specific time.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a radiation monitoring device, and more particularly to a radiation monitoring device suitable for radiation work control areas.

Area radiation monitors are known as radiation monitoring devices, and FIG. 1 shows the system configuration of a conventional area radiation monitor. This system consists of a radiation detector 11 installed in a radiation atmosphere, an alarm 3, an annunciator 4, a dose rate display meter 2, a high voltage power supply 8 installed in the central control room, a logarithmic dose rate meter 10, a low voltage power supply 9, and a trip Area monitor board 13 consisting of unit 11, recorder 12,
A high voltage power line 5, a low voltage power line 6, which connects each device.
Detection signal transmission line 7, meter dose rate signal line 1
4. It is composed of a trip signal transmission line 15, a dose rate signal line 15 for the recorder, and a dose rate signal line 16 for the recorder.

Next, a series of operations of the system will be explained.

A detection signal output from the radiation detector 1 installed in a radiation atmosphere is sent to the logarithmic dose rate meter 10 via the detection signal transmission line 7, and the detection signal and the radiation dose are transmitted inside the logarithmic dose rate meter 10. Perform conversion to rate.

Figures 2 and 3 show its block diagram and principle diagram.

FIG. 2 shows a logarithmic dose rate meter 10 comprising a discrete unit 19 comprising an amplifier 18, a wave height selection section 20, a Noritubflotub circuit 52, and a rate meter unit 22 comprising a pump circuit 21 and an amplifier 18. Third
The diagram shows capacitor C025, diode 26, and resistor R12.
7. The principle of a pump circuit composed of a capacitor Ct28 and an OP amplifier 29 is shown. Let the voltage of the pulse input signal 17 be V, and when n pulses are input in 1 second, the output voltage is v, and the dose rate is overpowered by Y@m t
= n V p Ce Rt is output.

Logarithmic dose rate meter 10. The output dose rate value is indicated to the meter of the logarithmic dose rate meter 10, is recorded to the recorder 12 via the recorder dose rate signal line 16, and is transmitted via the meter dose rate signal 2 in 14. and is output to the meter 2 installed in a radiation atmosphere. Further, when the dose rate value under the radiation atmosphere becomes abnormal, it is output from the trip unit 11 to the alarm device 3 and the annunciator 4 via the trip signal line 15. The conventional general area radiation monitoring system is as described above, and it is capable of centrally monitoring the radiation dose value in the radiation atmosphere; Dose rate instructions and alarms can be issued in the above atmosphere, but since an analog rate meter is used, the numbers displayed and displayed may vary due to variations in the constants of commonly used circuit elements such as resistors and capacitors. There may be an error in the rate, and it is necessary to make adjustments using a variable resistor or the like to correct the error.Furthermore, since fluctuations occur over time, it is necessary to readjust at regular intervals.

Furthermore, at low dose rates, the input pulses are sparsely generated, which is particularly likely to cause errors in measurement results. In addition, separate transmission lines are used to cable between the central monitoring equipment and multiple radiation detector meters and alarms installed in the radiation atmosphere, resulting in high cable installation costs and reduced flexibility when adding measurement points. It has been declining. In addition, the central monitoring device requires as many meters as the number of measurement points on the monitoring panel, and has the disadvantage that the central monitoring device becomes extremely large.

The present invention has been made in view of the above circumstances, and its purpose is to digitally measure radiation levels at a radiation measurement terminal station having a processor section, and to send the measurement results as digital signals to a central monitoring device. The object of the present invention is to provide a radiation monitoring device that has excellent measurement accuracy and stability, reduces cable costs, and has excellent monitoring functions.

In the present invention, a processor section is installed in a radiation atmosphere, a radiation measurement terminal station is installed for transmission with a higher-level device, and the pulse signals output from the radiation detector are counted by a digital counting method, and the processing by the processor section is performed. Perform the dose rate conversion,
It is characterized by performing digital multiplex transmission of calculation results to a central monitoring device.

Next, one embodiment of the present invention will be described with reference to the drawings.

FIG. 4 shows a radiation measurement terminal station 31 installed in a radiation atmosphere. Figure 5 shows the central control station 4 installed remotely.
1 and the above-mentioned terminal station. The radiation measurement terminal station 31 includes a radiation detector 1 that detects a radiation dose, a high voltage power supply 8 that supplies the high voltage for detection, a low voltage power supply 9 that supplies a low voltage for amplifying the detection signal, and counts detector pulse signals. , a pulse signal processing section 33, a processor section 32 that calculates the pulse counting result and converts it into a dose rate, and a calculation section 18''.
, 11 A memory section 36 that stores data, programs, etc., a transmission control section 35 that controls transmission with the upper level, and a dose rate display.
Display unit 34, alarm device 3 that issues an abnormality alarm in a radiation atmosphere
The central management station 41 includes a transmission control unit 58 that controls transmission with the terminal stations, a memory unit 57 that stores transmitted dose rate data, programs, etc., and a unit that records the dose rate at the location where the detector is installed. Screen display section 39 and recording section 4 for displaying and recording
0. A processor unit 56 that calculates the cumulative dose value of each radiation detector installation location, calculates the average value of the dose rate within a certain period, and creates a dose rate distribution map, etc.; the processor unit 56 and the screen display unit 39; The system includes an input/output control section 38 that interfaces with the section 40, and a common transmission path 51 through which a central management station and a plurality of radiation measurement terminal stations 31 are commonly connected to the central management station 41.

Next, the operation of one embodiment of the present invention will be explained.

In the radiation measurement terminal station 31 shown in FIG. 4, the radiation detector 1 detects the dose in the radiation atmosphere, and the pulse signal processing section 33 counts the detected pulse signals for a certain period of time. The count value is sent to section 32. Next, details of the pulse number counting operation will be explained using FIG. 6. FIG. 6 is a detailed block diagram of the pulse signal processing section.

A wave height selection unit 20 that cuts noise in the detector output, an input level converter 42 that determines a range of input level values suitable for input to a digital circuit, a basic clock generation circuit 50 that generates a basic clock, and a detection signal count. A detector output pulse number counter circuit 44, a basic pulse number counter circuit 49 that counts the basic clock, a pulse input signal 17 from the detector and a basic clock pulse number counter overflow signal 54 output from the basic clock pulse number counter circuit 49. Logical sum circuit 4 that calculates logical sum with
3, the processor section 32 clears the basic clock pulse generation circuit 49 and -detector output pulse counter circuit 44 in advance before measurement, and after the clearing is released, the basic clock pulse number output from the basic clock generation circuit 50. The basic clock pulse number counter circuit 49 starts counting, and at the same time, the detector output pulse number counter circuit 44 starts counting the number of detector output pulses. Then, when the count value of the basic clock pulse number counter circuit 49 overflows, the basic clock pulse number counter circuit 4
9, sends a basic clock number counter overflow signal 54 to the processor section 32 as an interrupt signal, and at the same time prohibits input of the detector output pulse to the detector output pulse number counter circuit 44 in the OR circuit 43; The processor section 32 receiving the interrupt signal reads the count value output from the data output section 47 of the detector output pulse number counter circuit 44. After reading the count value of the detection pulse input signal processing unit 33, the processor unit 32 in FIG. 4 performs a calculation to convert the count value into a dose rate, and stores the dose rate in the memory unit 36. Transmission control section 35
When receiving a request to send the personnel rate value from the central supervisory station 41, it sends an interrupt signal to the processor section 32 via the terminal internal bus 37, and sends the latest dose rate amount to the central station via the common transmission line 51. It is transmitted to the supervisory room 41. Middle A in Figure 5
Center*m541-cu, radiation measurement m station 31x')f
The flaned dose rate values are stored in the memory section 57, displayed and recorded, and the processor section 56 calculates the cumulative dose in each radiation atmosphere, calculates the average value of the dose rate within a certain period, etc. In addition, each radiation measurement terminal station 31 has an address, and since a transmission command is issued by specifying the address of the terminal station 31 from the central supervision station 41, only the radiation measurement terminal station 31 with the matching address is sent to the central supervision station 41. It is now possible to transmit data to

As described above, according to one embodiment of the present invention, the processor section 32.
The radiation measurement terminal station 31 counts pulse signals output from the radiation detector 1 using a digital counting method, converts the dose rate using software processing, and sends it to the central management station 4.
1, it is possible to measure radiation dose rates with greater accuracy than devices using conventional analog rate meters.It also has monitoring functions such as cumulative dose display and average value display. It is possible to realize a radiation monitoring device with excellent improvement in radiation.

By using the radiation monitoring device according to the present invention, measurement accuracy, stability, and monitoring function are excellent, and the floor space of the central monitoring device is reduced, cable installation costs are reduced,
This has the effect of improving flexibility when adding measurement points.

[Brief explanation of drawings]

Figure 1 is a system configuration diagram of a conventional radiation monitoring device;
The figure is a block diagram of the logarithmic dose rate needle, Figure 3 is a principle diagram of the pump circuit, Figure 4 is an internal configuration diagram of the radiation measurement terminal, Figure 5 is a system configuration diagram of the radiation monitoring device of the present invention, and Figure 6 is a diagram of the system configuration of the radiation monitoring device of the present invention. The figure is a detailed block diagram of the pulse signal processing section, and FIG. 7 is a diagram showing the processing steps in the radiation measurement terminal station of the radiation monitoring apparatus of the present invention. 1... Radiation detector, 2... Meter, 3... Alarm, 4... Annunciator, 5... High voltage power line, 6... Low voltage power line, 7... Detection signal transmission Line, 8...High voltage power supply, 9...Low voltage power supply, 10...
・Logarithmic dose rate meter, 11...Trip unit, 12・
...Recorder, 13...Area monitor board, 14...Dose rate signal line for meter, 15...Trip signal transmission line 1.16...Dose rate signal line for recorder, 1
7...Pulse input signal, 18...Amplifier, 19...
・Discrete unit, 20... Waveform sorting section, 2
DESCRIPTION OF SYMBOLS 1... Bumping circuit, 22... Rate meter unit, 23... Dose rate signal, 24... Rectangular wave input,
25... Capacitor C1, 26... Diode, 2
7...Resistor Ri128...Capacitor Ct, 29.
・・OP amp, 30... Output voltage ■2.31...
・Radiation measurement terminal station, 32... Processor section, 33...
- Pulse signal processing section, 34... Display section, 35... Transmission control section, 36... Memory section, 37... Terminal internal bus, 38... Input/output control section, 39... screen display section,
40...Recording department, 41...Central supervision room, 42...
Level converter, 43... OR circuit, 44... Detector output pulse number counter circuit, 45... Pulse input signal after pulse height selection, 46... Pulse input signal after level conversion, 47... Pulse number counter input signal, 48... Pulse number count value data, 49... Basic pulse number counter circuit, 50... Basic clock generation circuit, 51... Common transmission path, 52... Clip-flop circuit , 53...
- Counter clear signal, 54... Basic clock number counter overflow signal, 55... Central management station internal bus, 56... Processor section, 57... Memory section, 5
8...Eden No. 4 Figure 31 1 567 Figure 5 Ivy 6 Figure ¥] 7 Figure

Claims (1)

[Claims] 1. A radiation measurement terminal station and a transmission control unit that are installed in a radiation atmosphere and include a radiation detector that outputs pulse signals, a processor section, a transmission control section, a memory section, and a pulse signal processing section. and at least one central control station installed remotely, which has a processor section, a memory section, a display means, and a recording means, and a transmission path for transmitting data between the two stations, and the radiation detection terminal station is configured to detect radiation within the radiation terminal station. The pulse output signal of the device is counted by the signal processing section using a digital counting method, and the processor section and the memory section perform calculation processing to convert it into a radiation dose rate, and the calculation result is sent to the central control station via the transmission line. A radiation monitoring device characterized by transmitting the received dose rate value as a digital signal and displaying and recording the received dose rate value at a central control station. 2. In the radiation monitoring device according to claim 1, the transmission line is configured as a common transmission line to which a plurality of radiation measurement terminals are commonly connected, and the calculation result of the radiation dose rate is A radiation monitoring device characterized in that it transmits to a central control station by time division multiplexing transmission via a common transmission path. 3. Permissible Range of Claims 1. The radiation monitoring apparatus according to claim 1, wherein a display means is provided in the radiation measurement terminal station to display the dose rate. 4. In the radiation monitoring apparatus according to claim 1, the radiation measurement terminal station is provided with an alarm, and the radiation measurement terminal station transmits the dose rate alarm level set value from the central management station to the radiation measurement terminal station. A radiation monitoring device that generates an alarm when a dose rate measurement value reaches a dose rate alarm level setting value or more. 5. The radiation monitoring device according to claim 1, wherein the integrated dose rate value of each radiation detector installation location is displayed and recorded at the central monitoring station. 6. A radiation monitoring device according to claim 1, characterized in that the radiation monitoring device calculates an average value of the dose rate of a radiation measurement terminal station within a certain period of time, and displays and records the calculation results. 7. In the radiation monitoring device according to claim 1, the dose rate distribution map of the radiation measurement area is displayed using a display means provided at the central control station, and recorded using a recording means provided at the central control station. A radiation monitoring device characterized by: 8. The monitoring device according to claim 1, wherein the pulse signal processing section includes a basic clock pulse generation circuit, a basic clock pulse number counter circuit, and a set value overflow signal output from the basic clock pulse number counter circuit. It has an OR circuit that performs an OR with the detector output pulse, and a detector output pulse number counter circuit that counts the number of pulses output from the OR circuit, and the processor section calculates the basic clock pulse in advance before measurement. Clear the generation circuit μ detector output pulse number counter circuit and
After the rear release, the basic clock pulse number output from the basic clock pulse generation circuit is started to be counted by the basic clock number counter circuit, and at the same time, the detector output pulse number is started to be counted by the detector output pulse number counter circuit, The above-mentioned basic clock pulse number counter circuit sends an interrupt signal to the processor section, and at the same time, the above-mentioned OR circuit prohibits input of the detector output pulse to the detector output pulse number counter circuit, and the above-mentioned interrupt signal is A radiation monitoring device characterized in that a processor unit receiving the radiation measures the radiation dose rate by reading the detector output/count value of the pulse number counter circuit.