JPS5984177A - Radioactive rays monitoring device - Google Patents

Abstract

PURPOSE:To obtain a superior monitoring function by measuring a radiation level digitally and deciding digital conversion width previously. CONSTITUTION:The output voltage V59 of a radiation detector 1 is added by addition 63 to a reference voltage Vref64 and the result is inputted to an analog/ digital conversion processing part 33. When the output voltage V59 is positive the reference voltage Vref64 is set to a proper negative voltage to obtain a large positive voltage as the output voltage Vo65 of the adder. The analog/digital conversion processing part 33 performs conversion into a digital extent and a processor 32 detects the extent exceeding a conversion range through a terminal station internal bus 37 to generate an alarm.

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 1 installed in a radiation atmosphere, an alarm 3, an annunciator 4, a dose rate display meter 2, and a pressure power source 8 installed in a central monitoring room.
, logarithmic dose rate meter 10, low voltage power supply 9, trip unit 1
Area monitor board 13 consisting of 1, recorder 12, high voltage power supply line 5 connecting each device, low voltage power supply input 6, detection signal transmission line 7, dose rate signal line 14 for meter, trip signal transmission line 15, recording 4'1q are formed from the meter dose rate signal line 15 and the recorder dose rate signal line 16.

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 is converted to an in rate inside the logarithmic dose rate meter 10. Perform the conversion.

The dose rate value output from the logarithmic dose rate meter 10 is instructed 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 recorded as a line view rate signal for the meter. The signal is outputted to the meter 2 installed in a radiation atmosphere via the line 14t. Further, when the dose rate value under the radiation atmosphere becomes abnormal, it is outputted to the alarm device 3 and annunciator 4 via the trip unit 11 and the trigger 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, and is also capable of issuing dose rate value instructions and alarms in the above atmosphere. However, since an analog rate meter is used, there may be an error in the displayed counting rate due to variations in the constants of commonly used circuit elements such as resistors and capacitors, so a variable resistor is used to compensate for this error. It is necessary to make adjustments based on the above factors, and since fluctuations occur over time, it is necessary to readjust at regular intervals. In addition, separate transmission lines are used to cable between the central monitoring equipment, 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, which has the disadvantage that the central monitoring device becomes extremely large.

In addition, there was a drawback that abnormalities such as disconnections in the radiation detector could not be detected under normal conditions.

The present invention was made in view of these circumstances, and
The purpose of this is to digitally measure radiation levels at a radiation measurement terminal station with a processor, and at that time, to detect not only defects in the radiation monitoring device itself, but also defects in the radiation detector. The object of the present invention is to provide a radiation monitoring device with 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 an analog signal output from a radiation detector is converted into a digital quantity. The digital conversion width is determined in advance so that the full scale of the input signal is kept within the full scale of the analog-to-digital converter input, and if the conversion result exceeds the full scale, it is detected as an abnormality in the radiation detector. .

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

In Figure 2, the device is installed in a radiation atmosphere. A radiation measurement terminal station 31 is shown. Figure 3 shows a 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 the radiation dose, a high voltage power supply 8 that supplies the high voltage for detection, and a detection signal increase of 11%.
a low-voltage power supply 9 that supplies low voltage for
3. A processor unit 32 that calculates digital quantities and converts them into dose rates, a memory unit 36 that stores calculation data, programs, etc., a transmission control unit 35 that controls transmission with the upper level, and a display unit 34 that displays dose rates. The central management station 41 includes a transmission control unit 58 which controls transmission with the terminal stations, and stores the transmitted dose rate data, programs, etc. memory section 5
7. Display and record the dose rate at the detector installation location, screen display section 39, recording section 40, calculate the cumulative dose value at each radiation detector installation location, calculate the average dose rate within a certain period, dose rate The system consists of a processor section 56 that creates distribution maps, etc., an input/output control section 38 that interfaces the processor section 56 with a screen display section 39, and a recorder 40. The stations 31 are composed of a common transmission path 51 that is commonly connected to a central management station 41 .

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

In the radiation measurement terminal station shown in FIG. 2, the radioactivity detector 1 detects the dose in the radiation atmosphere, the detected analog signal is converted into a digital quantity by the analog-to-digital conversion processing section 33, and then sent to the processor section 32. Send.

FIG. 4 is a detailed explanatory diagram of analog-to-digital conversion processing. The horizontal axis represents the analog input signal, and the vertical axis
Represents a digital output signal.

When converting into a digital quantity, the digital conversion width is set to full scale in the analog-to-digital conversion processing section 33, so there is no Fi, and by limiting the conversion range,
In the example of Fig. 4, the abnormal range of the radiation detector is digital output signal 111, old, 100 or more, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000, 000...
. . . It is possible to detect the shaded portion below 011. An example of this is shown in FIG. The output voltage V59 of the radiation detector 1 is added to the reference voltage Vref64 by an addition 63 and is input to the analog-to-digital conversion processing section 33.

Adder output voltage■. 65 is as shown in the following formula.

At this time, if the output voltage V59 of the radiation detector 1 is a positive voltage, by setting the reference voltage V ref 64 to an appropriate negative voltage, if the radiation detector 1 is disconnected,
Since the output voltage V disappears, the adder output voltage VI, 65
becomes a large positive voltage, and the analog/digital conversion processing section 3
3 is converted into a digital quantity, and via the terminal internal bus 37, the processor section 32 detects that the conversion range has been exceeded and issues an alarm. Limiting the conversion range can be easily done in analog-to-digital converters.

The processor section 32 in FIG. 2 reads the count value from the analog-to-digital conversion processing section 330, performs a conversion calculation from the first count to a dose rate, and stores the dose rate in the memory section 36. When the transmission control unit 35 receives a request to transmit a dose rate value from the central supervisory agent 41, it sends an interrupt signal to the processor unit 32 via the terminal internal bus 37, and transmits the latest dose rate value via the common transmission unit 51. and transmits it to the central control agent 41. Third
In the central control station 41 in the figure, the dose rate values transmitted from the radiation measurement terminal station 31 are stored in the memory unit 57, and are displayed and recorded.In the processor unit 56, the integrated line in each radiation atmosphere is calculations, and average dose rate calculations within a certain period of time.

Furthermore, each radiation measurement terminal station 31 has an address, and since the central control agent 41 issues a transmission command by specifying the address of the terminal station, the radiation measurement terminal station 31 with the matching address
The information is transmitted only to the central control agent 41.

As described above, according to one embodiment of the present invention, the radiation measurement terminal station 31 and the central management station 41 have processor units 32 and 56.
, and converts the analog signal output from the radiation detector 1 into a digital signal in the radiation measurement terminal 31 and constantly monitors it, thereby detecting defects in the radiation detector. A radiation monitoring device with improved self-diagnosis function can be realized.

By using the radiation monitoring device according to the present invention, it is possible to detect not only self-monitoring of the radiation monitoring device but also abnormalities in the radiation detector.

[Brief explanation of drawings]

Figure 1 is a system configuration diagram of a conventional radiation monitoring device;
Zusha radiation measurement terminal station internal configuration diagram, Figure 3 is a system configuration diagram of the radiation monitoring device of the present invention, Figure 4 is a detailed explanatory diagram of analog-to-digital conversion processing, and Figure 5 is an embodiment of the present invention. FIG. 6 is an explanatory diagram showing a sixth processing step. △ 1... Radiation detector, 2... Meter, 3... Alarm, 4... Annunciator, 5... High voltage power supply line, 6... Low voltage power supply line, 7...Detection signal transmission line, 8...
・High voltage power supply, 9...Low voltage power supply, lO...Logarithm l1i
j! Rate meter, 11...Trip unit, 12...
Recording meter, 13... Area monitor board, 14... Dose rate signal line for meter, 15... Trip signal transmission line, 16... Dose rate signal line for recorder, 31...
Radiation measurement terminal station, 32... Processor section, 33...
Analog-digital conversion processing section, 34... display section,
35...Transmission control unit, 36...Memory unit, 37...
- Terminal internal bus, 38... Input/output control unit, 39...
Screen display section, 40... Recording section, 4J... Central management station, 55... Central management station internal bus, 56... Processor section, 57... Memory section, 58... Transmission control section , 5
9...Radiation detector output voltage V1.60...Resistance 1
41.61...Resistance ratio 2.62...Resistance R. 63...Adder, 64...Reference voltage ref, 65
... Adder output■. . 30 Figure 4 5th flash Figure 6

Claims (1)

[Claims] 1. A radiation measurement terminal station installed in a radiation atmosphere and having a radiation detector that outputs an analog signal, a processor section, a transmission control section, a memory section, and an analog/digital conversion processing section, and transmission. It consists of at least one central management station installed remotely having a control section, a processor section, a memory section, a display means, and a recording means, and a transmission line for transmitting data between the two stations, The radiation detector analog output signal is converted into a digital quantity by the analog/digital conversion geography section, and the processor section and 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. transmitted as a digital signal via
A radiation monitoring device that displays and records transmitted dose rate values at a central control station. 2. In the radiation monitoring apparatus according to claim 1, means is provided for outputting a signal far from the normal output range when the radiation detector is disconnected, and the analog output signal from the radiation detector is converted into an analog-to-digital conversion process. When converting into a digital quantity in the section, the digital conversion width is determined in advance so that the full scale of the output of the radiation detector during normal operation falls within the full scale of the input of the analog-to-digital conversion processing section, and the conversion result is A radiation monitoring device characterized in that if the value exceeds that value, it is determined that the radiation detector is disconnected.