JPS5826442A - Controller for life of counter tube - Google Patents

Abstract

PURPOSE:To permit the life of a GM counter tube to be known accurately and enable measurement error and proper exchange time to be estimated by providing the pulse integration circuit which is applied for the measurement of radioactive rays and posseses preset function and the alarm generating part. CONSTITUTION:When a GM counter tube 11 receives the radioactive ray to be measured, the counter tube 11 transmits the pulse signal in a number which is proportional to the dose of radioactive rays, and the pulse signals are counted by a preset-type pulse integration circuit 12 through a signal wire 13. The integration value is displayed on an integration display device 14. In the preset- type pulse integration circuit 12, the number of counts which shows the estimated life of the sealed-up gas in the GM counter tube 11 is preset beforehand. When the integration value is attained, alarm signal is transmitted from the pulse integration circuit 12 to the alarm display part 15 to inform the life of the GM counter tube 11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a counter life management device suitable for use in devices that measure radiation.

In general, a Geiger-Mueller counter (hereinafter referred to as a GM counter) is one of the widely used radiation detectors because it can constitute a radiation measuring device using an inexpensive and simple electronic circuit. By the way, the conventional GM counter tube has a limited lifespan due to the principle of operation that utilizes the ionization phenomenon of the filled gas due to radiation, as the filled gas decomposes due to discharge. Therefore, devices using GM counters are usually equipped with alarm means to manage their lifespans. FIG. 1 is a block diagram of a conventional counter life management device using a GM counter. In this device, G
- The pulse signal output from the M counter 1 is sent to the logarithmic dose rate meter 3 via the detection signal cable 2, where it is logarithmically converted into an analog output, and then output to the dose rate indicator 4
Indicated by l/h position. In such a device, G
・When the M count vl approaches the end of its life, its plate length and counting start voltage decrease, and the indicated value of the dose rate indicator 4 falls below the normal background count value. An alarm is emitted from an alarm display 5. However, with such a device, the lifespan of G4vl autopsy count/d is determined based on a decrease in the counting rate, so it is already not normal at that point, and it is not possible to predict in advance the G4vl autopsy count/d. 'Also, since the counting rate continues to decline, it is impossible to produce a fixed error, and it is not possible to know a more accurate time of tremor for G'Nl counter I. .

The present invention was made in view of the above problems, and its purpose is to extend the lifespan of G-M Biji officers.

The above is an example of an embodiment of the present invention with reference to the drawings.
to act. Figure 2 is an example of a single channel, and 11 shown in the figure is a pulse 1 corresponding to the &l amount of the radiation phase input.
G・+v+ which outputs No. 5; Mi number tube, 12 is connected to the G-M correction number 1) via the signal overpass 13 and the same number 11
This is a Griset type, seven pulse booster circuit that integrates the Norse signals output from the This preset type multiplier product circuit 12 can reset the previously known life of the cMrl number tube 1 by the number of pulse counts, and also sends an alarm signal when the preset product value reaches a value of 1. There is only one output structure. Reference numeral 14 designates an integration display unit that displays the integrated value of the pulse integration circuit No. 2, and 15 represents an alarm display unit that issues an alarm upon receiving the signal output from the pulse integration circuit 12. . Next, the operation of the lifespan management device configured as described above will be explained. G
When the -MNi number tube 1 receives the radiation to be measured, it outputs a number of pulse signals proportional to the dose of radiation. The mother pulse signal is counted by the Noricella I type 1,000 pulse integration circuit 12 via the signal line 13, and the number of counts is accumulated. At this time, the integrated value of the Norset type pulse accumulation circuit 12 is displayed on the integrated display 14. by the way,
In the reset type pulse amplification circuit 12, a count number estimated to be the life of the gas filled in the G-M counter 1 is set in advance by 1. For example, in the case of commonly used halodan yarn gas, the life count is 10 to 1010, so the count is reset to a range of 10 to 100. Here, by using the G-M count v11 over time,
When the integrated value of the preset type pulse integrating circuit 12 reaches the upper preset integrated value, the pulse integrating circuit 12
A warning signal is output from the alarm display section 15, and the display section 5 issues an alarm informing of the lifespan of the GM anatomical tube 1.

In the above embodiment, the life management device for one GM counter tube has been described, but the present invention can also be applied to life management for a plurality of GM counter tubes. The embodiment will be explained using FIG. 3.

That is, this device includes GM counters 1-1 to 1-N corresponding to a plurality of channels, and these GM counters 11
The outputs of -1 to 1 NO-N are sent to the preset corresponding to each G/M counter 11-1 to 11-N via a switch 21 that switches the key-1 corresponding to each channel at certain fixed time intervals. It is connected to the shape/gurus calculation circuits 12-1 to 12-N. This pulisé, 1, form, and base calculation circuit 5-12-1 to 12-N are each G-M lucky number + gr1 no 1 to
The lifespan that can be estimated in advance of 1NoN is precertified by the count number. Further, the reset type pulse integration circuits 12-1 to 12-N have integration display sections 14-1 to 14-N and a GM counter 11-1 for displaying integration values, respectively.
~1 Alarm display section 15-1 to 15 that notifies the life of NO-N
-N is connected.

The operation will be explained below using FIG. 3 and the time chart FIG. 4. Each GM counter 1-1 to 11-N receives each radiation and outputs a pulse signal of 1 to KN according to the dose. 1 to KN for the same pulse signal are signal lines 16-1 to 1
6-N to the corresponding channel of the switch 21. In the switch 21, at the gate timing 01 to GN, each channel open time T1, -period 12
The switching operation is performed at time 0. When 1 to KN is input to the above-mentioned signal to the switch 2, only the signal corresponding to the open channel among the signals 1 to KFJ is output from the open switch 21 at time T1. Issued as 1~IN and corresponds to the subsequent selection 6-channel! The signal is input to reset type/wireless four-wire circuits 12-1 to 12-H. However, the input signal, Norise, 1-type pulse performance circuit 12-1 to 12
-N is counted and integrated. At the same time, the integration display sections 14-1 to 14-NK are displayed. As described above, the G-MNi number of each channel is 1l-1~
11-N's No. C Rusui No. h output is at time T1,
Sequential Zorisset I-type pulse integration circuits 12-1 to 12-N
It is accumulated at In such a device, the series reset type pulse tf* $1' circuit of a certain channel J2-1 to J2-1
When the integrated value of 2-N reaches the preset initial life product value, the integrating circuits 12-1 to 12-NJ and the information display section 15
A signal is emitted to -1 to 15-N, and the same report display section 15 to
1 to 15-N inform G- of the life span of one counter tube 11-1 to 11-N.

By the way, in the case of life management of multiple G-M counter groups,
For the life W management of a single G-Mi (-1 tube), the set life integrated values of the preset type pulse integration circuits 12-1 to 12-N are different. In this life management device, the counting time is switched by a switch 21 as shown in Fig. 3, so the counting time is shorter than that of a life management device with a single cutting tube. Integration circuit J2-1 to 12-N
The integrated count value of the G-M III [1-tube life management device shows a lower 1st shift for the life management system of multiple G-Miii tube groups than that of the single G-M 1-tube life management device, and the integrated value of the count of 1 shift cannot be obtained.Therefore, the preset type pulse accumulation in the life management device for multiple G/M tube groups (setting life of circuits 12-1 to 12-N) l'R calculation value is as follows. I decide.

As shown in Figure 4, each channel's opening time is T1.
, if one cycle of the switch 21 is T2, and the number of channels is N, 'I'2 = NT1, so T1/T2 = '/N.Therefore, the count integrated value of 4-' becomes '/N.

Therefore, the Noset type Nocellus & arithmetic circuits 12-1 to 12-
The set life cumulative value of N is G-M counter No.1 to 11-H.
It is sufficient to set it to 1/N of the estimated life count of the filled gas. For example, if you install 0 G/M playback tubes that use heavy gas with a Jn constant life count of 10 counts, the set life accumulated value of each Norisef 1/type pulse integration circuit will be 1010 x 1/ The count is 1o-109.

Furthermore, if a large amount of radiation is input to the G-M counter, the output pulse signal of each G-M counter will exceed the linear lens of the subsequent measuring instrument, and the indicated value of the measuring instrument will be lower than the actual one. There is a phenomenon in which the condition decreases (hereinafter referred to as suffocation state). Even in such a state, it is possible to easily realize a lifespan management device that can approximately control the lifespan. This will be explained below with reference to FIG.

In FIG. 5, No. 1 is a G-M@+ number tube which outputs a signal according to the radiation dose, and a signal #16 is passed to the output side of the KI number tube No. 1. A line coverage rate conversion circuit 17 is connected to the line coverage rate conversion circuit 17, and a direct current rate conversion circuit 19 is connected to the cathode terminal of the isometric tube 1 via the cathode output line 18. Also connected to the output side of the current pulse conversion circuit 19 is an OR sieve circuit 20 which receives the pulse signals output from both circuits 17 and 19.

The logic circuit 20 has input terminals 21 and 22, and the former is connected to the output side of the linear liquid rate conversion circuit 17, and the latter is connected to the output 1111 of the current/arm pulse conversion circuit 19, respectively.

On the other hand, a suffocation detection signal line 23 that indicates a state of suffocation is connected from the suffocation circuit 17 to the current)4 pulse conversion circuit 19, and each time the suffocation is detected, the same t#L pulse circuit 19 outputs 9 pulses. do. Further, a serial reset type pulse integration circuit 12 is connected to each 20 of the OR logic circuit II in iiJ, and integrates the input pulses. Same horizontal lift repair 1
2, the life count integrated value of the G-M counter 11 is set in advance, and when the count increase value of the G-M counter 12 reaches the integrated value, an alarm signal is output. 14 is an integration display unit for displaying the l*value of the reset type pulse counting circuit 12, and 15 is a signal outputting a signal in response to a signal output from the reset type pulse counting circuit 12. This is the display section.

10- Next, the operation of this device will be described with reference to Fig. 5.
The pulse No. 1M outputted from the signal line 16
It is input to the dose rate conversion circuit 17 via. Here,
Normal state: When the input of the nine dose rate conversion circuit 170 is within the linear range of the conversion circuit 17, the dose rate conversion circuit 17 outputs a number of pulse signals corresponding to the input, and the subsequent OR logic circuit 20 conversion circuit 17 to the current pulse conversion circuit 19, the current pulse circuit 19 does not output the pulse signal to the input terminal 22 of the logic circuit 20. Therefore, the base pulse signal from the dose rate conversion circuit 17 sent to the input terminal 21 of the logic circuit 20 is sent to the subsequent serial reset type/zerus multiplication circuit 12 as the OR output of the same logic circuit 20. Due to the large number of radiation inputs, the number of mother pulses output from the G-M counter 11 increases and exceeds the linear Lenz of the subsequent IfM quantity rate conversion circuit 17, that is, the conversion circuit 17 suffocates. If the condition occurs, the dose rate conversion circuit 17
outputs a smaller number of pulse signals than the number of pulse signals sent from the G-M adjustment tube 1, and sends them to the input end 21 of the subsequent ORi and embedded circuit 20. At the same time, a suffocation detection signal is sent from the +W quantity rate conversion circuit 17 to the current pulse conversion circuit 19 via the suffocation detection signal line 23. Upon receiving the suffocation detection signal, the current pulse conversion circuit 19 immediately converts the G-M
A cathode current that does not decrease even when the counter tube 11 is suffocated is received through the cathode output line 18, and the cathode current is converted into cellus and outputted. Here, the subsequent logic circuit 20 includes a dose rate conversion circuit 17 and a current pulse circuit 19.
In place of the reduced output of the former line φ quantity rate converter circuit which is in a state of suffocation due to the 0 output, the output of the current circuit 19 with a large number of cell signals is used as the OR output of the same logic circuit 20. , and sends it to the preset type mother pulse product nose circuit 12. Therefore, this pulse integration circuit 12 uses the O
The output of the R logic circuit 20 is received and counted. At the same time, this integrated value is displayed by the integrated display section 14. However, when the integrated value of the preset type pulse calculation circuit 12 reaches the set life integrated value that is estimated to be the life of the injection gas in the G-IVI counter 1, the similar calculation circuit 12 sends a signal to the information display section 15. This signal indicates the lifespan of the FjJ anatomical number tube 11.

In this way, alternative A? By generating pulses, it is possible to reduce as much as possible the miscounts of the preset type pulse integration circuit 12 in the suffocation state.

As described above, according to the present invention, in the conventional life management of counter tubes, the problem of unclear replacement timing is improved, and a reliable replacement timing is indicated. In addition, since the set integrated value can be selected freely, it is possible to set a replacement period for the counter tube with a margin that takes into account the variation in the life of the gas filled in the counter tube, and in a measurement system that uses 11-1, there is less error. It can provide system data. Furthermore, in radiation measurement systems such as regional monitoring systems that have multiple channels of 13-counter tubes, the number of counters that need to be prepared in advance can be determined by comparing the set integrated value of each channel and the integrated status, which is convenient for purchasing. becomes. In particular, this becomes more noticeable as the number of channels increases.

Furthermore, even in the suffocation state caused by a large amount of radiation scarlet input, approximate integration is possible using alternative pulses, and highly reliable counter life management data can be obtained, making it suitable for life management of the counter tube. It is possible to provide a lifespan management device for a counter tube that can accurately determine when to replace the counter tube.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional device, and FIG. 2 is a diagram of a G according to the present invention.
- A configuration diagram of a life management device for one M counter, FIG. 3 is a configuration diagram of a life management device for a plurality of G/M counter groups according to the present invention, and FIG. A time chart showing timing, FIG. 5 is a GM counter 1 according to the present invention that performs approximate integration using alternative pulses in a state of suffocation.
4- The lifespan of the tube 5) In the configuration diagram of the device M). 12.12-1~12-N... Noriseso I/Form/J?
Rusu product (roll) 1 ■! 1st Road, 74.14-1~14-N・
・・Shigu display section, 15.15. -1 to 15-N... Alarm display section, 17... Dose rate conversion circuit, 18... Cathode current output line, 19... Current pulse conversion circuit, 20
...OR-logical circuit.

Claims (2)

[Claims] (1) A counter that outputs 1,000 Lus according to the radiation input, and a preset I that integrates the output of this counter and the 1,000 Lus signal.
- A lifespan management device for a counter, characterized in that it is equipped with a functional glucometer integration circuit and a alarm generator that generates an alarm output when the measured integrated value reaches the preset integrated value. (2) When equipped with multiple channels of counter tubes and/or pulse integration circuits, a switch may be installed between these counter tubes and the pulse integration circuit group to switch channels at certain intervals. A lifespan management device for a counter according to claim 1, wherein the lifespan of a plurality of counters is managed by controlling the lifespan of a plurality of counters.