JPS6311887A - Automatic range change-over type linear dose rate meter - Google Patents
Automatic range change-over type linear dose rate meterInfo
- Publication number
- JPS6311887A JPS6311887A JP15505186A JP15505186A JPS6311887A JP S6311887 A JPS6311887 A JP S6311887A JP 15505186 A JP15505186 A JP 15505186A JP 15505186 A JP15505186 A JP 15505186A JP S6311887 A JPS6311887 A JP S6311887A
- Authority
- JP
- Japan
- Prior art keywords
- range
- dose rate
- amplifier
- output
- switching
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 230000005855 radiation Effects 0.000 claims abstract description 17
- 238000005259 measurement Methods 0.000 claims description 12
- 239000003990 capacitor Substances 0.000 claims description 8
- 230000004044 response Effects 0.000 abstract description 3
- 230000007423 decrease Effects 0.000 description 11
- 230000002159 abnormal effect Effects 0.000 description 8
- 238000010586 diagram Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 3
- 244000145845 chattering Species 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000012886 linear function Methods 0.000 description 2
- 230000003321 amplification Effects 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000003199 nucleic acid amplification method Methods 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
Landscapes
- Measurement Of Radiation (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は原子力発電所等の放射線計測システムの線形線
量率計に係り、特に誤計測がなく精度よい線量率測定に
好適な自動レンジ切替型線斌率計に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a linear dose rate meter for radiation measurement systems in nuclear power plants, etc., and in particular to an automatic range switching type that is suitable for accurate dose rate measurement without measurement errors. Concerning wire inclination meter.
従来の放射ａｍ所定置としては、たとえば特開昭５７−
１０６８８５号公報に記載のように、放射線検出器から
の広範囲の電流信号を対数増幅する計測システムが知ら
れている。しかしこの対数増幅器の増幅誤差については
配慮されていなかった。一方で特開昭５７−１０６８８
５号公報の従来例に記載のように、手動レンジ切替手段
を有する直流増幅器による計測システムではレンジ切替
時の４８号に対して配慮されていなかった。As a conventional radiation am predetermined installation, for example, JP-A-57-
As described in Japanese Patent No. 106885, a measurement system is known that logarithmically amplifies a wide range of current signals from a radiation detector. However, no consideration was given to the amplification error of this logarithmic amplifier. On the other hand, JP-A-57-10688
As described in the conventional example of Publication No. 5, in a measurement system using a DC amplifier having a manual range switching means, no consideration was given to No. 48 when switching ranges.
上記従来技術は微少電流を対数増幅するさいの誤差につ
いて配慮されていない一方、増幅器の手動レンジ切替時
の信号の変動に対して配慮されておらず、測定精度が悪
い一方でレンジ切替時には測定できない等の問題があっ
た。特にレンジ切替えをリレー等で行なった場合には１
機械的動作による歪電流や容量変化に伴なう電流のため
計測線量率が変動するうえ、その変動により計測値が警
報レベルに達して誤警報を発生する可能性がある等の問
題点があった。The above conventional technology does not take into account errors when logarithmically amplifying minute currents, but also does not take into account fluctuations in the signal when manually changing the range of the amplifier, resulting in poor measurement accuracy and not being able to measure when changing ranges. There were other problems. Especially if the range switching is done using a relay etc.
There are problems such as the measured dose rate fluctuating due to strain current due to mechanical operation and current due to capacitance change, and the fluctuation may cause the measured value to reach the alarm level and cause a false alarm. Ta.
本発明の目的は測伝値の精度を上げるために対数増幅器
ではなく線形増幅器を用いるとともに、自動的にレンジ
切替えが可能でレンジ切替時に異常な重量率出力と誤警
報出力を行なうことのない自動レンジ切替型線形線量率
計を提供するにある。The purpose of the present invention is to use a linear amplifier instead of a logarithmic amplifier in order to improve the accuracy of measured values, and also to automatically switch ranges and avoid abnormal weight ratio output and false alarm output when changing ranges. To provide a range-switchable linear dose rate meter.
上記目的は、線形線量率計による線量率が一定値（判定
値）以上になった場合には線量率計内部のプログラムに
より判断し、現在のレンジ切替信号をオフすると同時に
１つ上のレンジ切替信号をオンさせ、放射線検出器の出
力の微少電流信号を増幅する増幅器のゲインを下げるこ
とによりレンジを１つ上げるとともに、線量率が一定値
（判定値）以下になった場合には同様に増幅器のゲイン
を上げることによりレンジを１つ下げるようにして自動
的なレンジ切替えを行ない、このさい上記２つのレンジ
切替えの判定値を異なる値として上のレンジに切替える
判定値よりも下のレンジに切替える判定値を小さくする
ことによりヒステリシスを持たせ、さらにレンジ切替時
には線量率計の計測値の表示およびう報出力を一定時間
だけ同一値に保持させたのち、再びレンジ切替後の増幅
器の出力信号を入力してｌａ重量率計測し続けるように
し、かつ上記のレンジ切替時の計測値の保持時間を増幅
器のレンジ切替後の帰還抵抗ＲとコンデンサＣによる時
定数Ｃ−Ｈの定数倍とすることにより達成される。The above purpose is to use a program inside the dose rate meter to determine when the dose rate measured by the linear dose rate meter exceeds a certain value (judgment value), turn off the current range switching signal, and switch to the next higher range at the same time. By turning on the signal and lowering the gain of the amplifier that amplifies the minute current signal output from the radiation detector, the range is increased by one level, and if the dose rate falls below a certain value (judgment value), the amplifier is also turned on. Automatic range switching is performed by lowering the range by one by increasing the gain of , and at this time, the above two range switching judgment values are set as different values and the range is switched to a lower range than the judgment value for switching to the upper range. By reducing the judgment value, hysteresis is provided, and when changing the range, the display of the measured value of the dose rate meter and the alarm output are held at the same value for a certain period of time, and then the output signal of the amplifier is changed again after changing the range. By inputting and continuing to measure the la weight factor, and by making the holding time of the measured value at the time of range switching described above a constant multiple of the time constant C-H by the feedback resistor R and capacitor C after changing the range of the amplifier. achieved.
上記自動レンジ切替型線形線量率計によれば。 According to the above automatic range switching type linear dose rate meter.
放射線検出器からの信号を増幅する増幅器の帰還抵抗を
切替えることにより計測値を精度よく増幅できると同時
に、その切替えを計測値と判定値の比較結果に応じて実
行することにより自動レンジ切替えを可能とし、このさ
いレンジ切替えの判定値を各レンジごとに上のレンジに
切替える時と下のレンジに切替える時と別にしてヒステ
リシスを持たせているので、レンジ切替時にそれぞれ切
替る２つのレンジ間でチャタリングすることが防止され
、さらにレンジ切替時の線量率計内のプログラムにより
レンジ切替前の線量率の計測値に一定時間だけ保持して
いるので、レンジ切替時に発生する増幅器４の出力の異
常信号の影響を除去して計測値の異常な誤出力および誤
表示を防止可能にするとともに不要な警報を出力するこ
ともなくなり、かつレンジ切替時の計測値の保持時間を
各レンジごとに上のレンジに切替える時と下のレンジに
切替える時と２種類の値をそれぞれ予め線量率計の記憶
部に格納しておくことにより、レンジ切替時の計測値の
保持時間を最短にすることができるとともに、レンジ切
替えのさいの帰還抵抗の切替えによるサージ等の吸収お
よび増幅器の安定化のために帰還抵抗Ｒと並列に設けた
コンデンサＣに応じて上記保持時間を時定数Ｃ−Ｈの定
数倍とすることにより、レンジ切替時の動作を最適化で
きる。〔実施例〕
以下に本発明の一実施例を第１図ないし第４図により説
明する。By switching the feedback resistor of the amplifier that amplifies the signal from the radiation detector, it is possible to amplify the measured value with high precision, and at the same time, automatic range switching is possible by performing the switching according to the comparison result between the measured value and the judgment value. In this case, the judgment value for range switching is set separately for each range, with hysteresis for when switching to the upper range and when switching to the lower range. Chattering is prevented, and since the dose rate measurement value before the range switch is held for a certain period of time by the program in the dose rate meter when the range is switched, the abnormal signal of the output of the amplifier 4 that occurs when the range is switched is prevented. It is possible to prevent abnormal erroneous output and display of measured values by removing the influence of By storing two types of values in advance in the memory of the dose rate meter, one for switching to the lower range and one for switching to the lower range, it is possible to minimize the holding time of the measured value when switching the range, and The above holding time should be set to a constant multiple of the time constant C-H according to the capacitor C installed in parallel with the feedback resistor R in order to absorb surges and stabilize the amplifier by switching the feedback resistor during range switching. This makes it possible to optimize the operation when switching ranges. [Embodiment] An embodiment of the present invention will be described below with reference to FIGS. 1 to 4.
第１図は本発明による自動レンジ切替型線形線量率計の
一実施例を示す全体構成図である。第１図において、１
は線形、ｔ１１址率計、２は放射線検出器、３は前ｒ！
ｉ増幅器、４は増幅器、５は帰還抵抗（Ｒ１−Ｒｎ）、
６はレンジ切替信号、７は前置増幅器出力信号、８は電
源線、９は高低圧電源、１０はデータバスである。FIG. 1 is an overall configuration diagram showing an embodiment of an automatic range switching type linear dose rate meter according to the present invention. In Figure 1, 1
is linear, t11 susceptibility meter, 2 is radiation detector, 3 is front r!
i amplifier, 4 is an amplifier, 5 is a feedback resistor (R1-Rn),
6 is a range switching signal, 7 is a preamplifier output signal, 8 is a power supply line, 9 is a high/low voltage power supply, and 10 is a data bus.
第１図の電離箱等の放射線検出器２は１Ｏ−１２Ａ程度
の微少電流信号を出力し、その信号は前置増幅器３に入
力されて増幅器４により増幅されたのち、その出力信号
７は線形線量率計１に入力する。その前置増幅器３の増
幅器４にはレンジのゲインを決定する帰還抵抗Ｒ１〜Ｒ
ｎが設けられ、これより離れた場所にある線形線量率計
１からのレンジ切替信号６によりリレーＲａｙが駆動さ
れて、帰還抵抗Ｒ１〜Ｒｎの１つが選択される。また増
幅器４には帰還抵抗Ｒ１〜Ｒｎと並列にレンジ切暫時の
サージ吸収と増幅器の安定化のためのコンデンサＣが設
けられる。その帰還抵抗（値）Ｒ１−ＲｎはたとえばＲ
１／１０＝Ｒ２，Ｒ２／１０＝Ｒ３，・・・・・・のよ
うにそれぞれ１／１０倍の抵抗値とすることにより、増
幅器４のゲインを１／１０倍ずつ低下させることができ
る。A radiation detector 2 such as an ionization chamber in Fig. 1 outputs a minute current signal of about 10-12A, and that signal is input to a preamplifier 3 and amplified by an amplifier 4, and then the output signal 7 is linear. Input to dose rate meter 1. The amplifier 4 of the preamplifier 3 has feedback resistors R1 to R that determine the gain of the range.
A relay Ray is driven by a range switching signal 6 from a linear dose rate meter 1 located further away from the linear dose rate meter 1, and one of the feedback resistors R1 to Rn is selected. Further, the amplifier 4 is provided with a capacitor C in parallel with the feedback resistors R1 to Rn for absorbing surges during range-off and stabilizing the amplifier. The feedback resistance (value) R1-Rn is, for example, R
By setting the resistance values to 1/10 times each as 1/10=R2, R2/10=R3, . . ., the gain of the amplifier 4 can be reduced by 1/10 times.
一方の線形線量率計１は中央処理部ＢＰＵ、主記憶部Ｍ
ＥＭ、内部バスコントロール部ＢＣ，ディジタル出力部
ＤＯＩ、ＤＯ２，アナログ入力部ＡＩ、アナログ出力部
ＡＯ，データバス１０から構成される。上記の前置増幅
器３により増幅された計測信号（出力信号）７はアナロ
グ入力部ＡＩにより入力され、中央処理部ＢＰＵにより
線量率（ｍＲ／ｈ）に換算され、アナログ出力部ＡＯを
経由して表示されるとともに、主記憶部ＭＥＭに格納さ
れた警報判定値より大きいか否かを判定し、大きい場合
にはディジタル出力部００２より外部へ警報を出力する
。One linear dose rate meter 1 includes a central processing unit BPU and a main memory unit M.
It consists of an EM, an internal bus control section BC, digital output sections DOI and DO2, an analog input section AI, an analog output section AO, and a data bus 10. The measurement signal (output signal) 7 amplified by the preamplifier 3 is input to the analog input unit AI, converted to a dose rate (mR/h) by the central processing unit BPU, and then sent via the analog output unit AO. At the same time, it is determined whether the value is larger than the alarm judgment value stored in the main memory unit MEM, and if it is larger, an alarm is output from the digital output unit 002 to the outside.
また高低圧電源９は線形線量率計１に電力を供給すると
ともに、放射線検出器２の駆動用電力および前置増幅器
３の増幅器４の動作用電力を電、′、１１ｔｊＡ８を経
由して供給する。Further, the high/low voltage power supply 9 supplies power to the linear dose rate meter 1, and also supplies power for driving the radiation detector 2 and power for operating the amplifier 4 of the preamplifier 3 via the electric power, ', 11tjA8. .
つぎにレンジ切替えについては、前置増幅器３の増幅器
４のたとえば帰還抵抗Ｒ１によるレンジ１のゲインは帰
還抵抗Ｒ２（＝Ｒ１／１０）によるレンジ２のゲインの
１０倍であり、帰還抵抗Ｒ１のレンジ１では線量率Ｏ〜
１０ｍＲ／ｈ、帰還抵抗Ｒ２のレンジ２では線量率Ｏ〜
１００ｍＲ／ｈとなるように調整すると、線量率０〜１
０ｍ Ｒ／ ｈの最小のレンジ１では帰還抵抗Ｒ１のレ
ンジ切替リレーＲｙをオンさせて、前置増幅器３の出力
信号７の電圧０〜ＩＯＶが線量率Ｏ〜１゜ｍ Ｒ／ ｈ
に対応するようにできる。これより線形線量率計１では
入力電圧信号（前置増幅器出方信号）７の電圧Ｏ〜１ｏ
ｖｔ＆線量率０〜ｌＯｍＲ／ｈへ次式の１次関数により
変換できる。Next, regarding range switching, for example, the gain of range 1 due to feedback resistor R1 of amplifier 4 of preamplifier 3 is 10 times the gain of range 2 due to feedback resistor R2 (=R1/10), and the gain of range 2 due to feedback resistor R2 (=R1/10) is 10 times 1, the dose rate O~
In range 2 with 10 mR/h and feedback resistance R2, the dose rate is O~
When adjusted to 100 mR/h, the dose rate is 0 to 1.
In the minimum range 1 of 0m R/h, the range switching relay Ry of the feedback resistor R1 is turned on, and the voltage 0 to IOV of the output signal 7 of the preamplifier 3 is set to a dose rate of 0 to 1゜mR/h.
It can be made to correspond to From this, in the linear dose rate meter 1, the voltage of the input voltage signal (preamplifier output signal) 7 is O~1o.
It can be converted to vt & dose rate from 0 to 1OmR/h using the following linear function.
（Ｂ足車） ＝Ｇｘ （入力電圧）＋Ｂ ・旧・・
（１）ただしＧ、Ｂはレンジごとに決定する変換定数で
ある。(B caster) = Gx (input voltage) + B ・Old...
(1) However, G and B are conversion constants determined for each range.
また線形線量率計１では入力電圧信号（前置増幅器出方
信号）７が上昇してたとえば電圧９ｖ以上になった場合
にはレンジ２の帰還抵抗Ｒ２のレンジ切替リレーＲｙを
オンさせて入力信号電圧０〜ＩＯＶが線量率Ｏ〜１００
ｍＲ／ｈに対応するようにさせるとともに、（１）式の
１次関数の変換定数Ｇ、Ｂをレンジ２用の値とする。こ
のレンジ１からレンジ２へのレンジ切替時には前置増幅
器３のレンジ２の帰還抵抗Ｒ２とコンデンサＣによる時
定数Ｃ−Ｒ２の定数倍（たとえば５倍）を保持時間τ（
＝５・Ｃ−Ｒ２）として、この保持時間τだけ線形線量
率計１による線量率の計測値の表示および警報出力をレ
ンジ１の状態に保持させる。同じくレンジ２において入
力電圧信号（前置増幅器出力信号）７が低下してたとえ
ば電圧０．８ｖ以下になった場合には同様にしてレンジ
１に切替えるとともに、このレンジ２からレンジ１への
レンジ切替時にはレンジ１の帰！抵抗Ｒ１とコンデンサ
Ｃによる時定数Ｃ−Ｒ１の定数倍（たとえば５倍）の保
持時間τ （＝５・Ｃ−Ｒ１）だけ計測値をレンジ２の
状態に保持させる。In addition, in the linear dose rate meter 1, when the input voltage signal (preamplifier output signal) 7 rises to, for example, 9V or more, the range switching relay Ry of the feedback resistor R2 of the range 2 is turned on and the input voltage signal is Voltage 0~IOV is dose rate O~100
mR/h, and the conversion constants G and B of the linear function in equation (1) are set to values for range 2. When switching from range 1 to range 2, the holding time τ(
=5·C-R2), the display of the measured value of the dose rate by the linear dose rate meter 1 and the alarm output are held in the range 1 state for this holding time τ. Similarly, when the input voltage signal (preamplifier output signal) 7 decreases to, for example, 0.8 V or less in range 2, it switches to range 1 in the same way, and also ranges are switched from range 2 to range 1. Sometimes it's back to range 1! The measured value is held in the range 2 state for a holding time τ (=5·C-R1) which is a constant multiple (for example, 5 times) of the time constant C-R1 by the resistor R1 and the capacitor C.
第２図は第１図の線形ａ置針１の処理動作フローチャー
トである。第２図において、処理ブロックＡでは電離箱
等の放射線検出器２の微少電流信号を前置増幅器３によ
り増幅した入力電圧信号（Ｖ）をアナログ入力部ＡＩに
より入力し、処理ブロックＢでは（１）式により当該レ
ンジの線量率（ｍＲ／ｈ）に換算し、処理ブロックＣで
は警報判定値より大きいかどうかを判定する。処理ブロ
ックＤ、Ｅではそれぞれ当該レンジ最大値の９０％以上
、当該レンジ最大値の８％以下の値になったかどうかを
内部プログラムにより判定し、当該レンジ最大値の９０
％未満で８％より大きければ処理ブロックＦで線量率を
アナログ出力部Ａ○を経由して表示および出力するとと
もに、処理ブロックＧでは警報判定値より大きい場合に
はディジタル出力部ＤＯ２より外部へ警報を出力する。FIG. 2 is a flowchart of the processing operation of the linear a positioner 1 shown in FIG. In FIG. 2, in processing block A, an input voltage signal (V) obtained by amplifying a minute current signal from a radiation detector 2 such as an ionization chamber by a preamplifier 3 is inputted to an analog input unit AI, and in processing block B, (1 ) is converted into a dose rate (mR/h) for the range, and in processing block C it is determined whether the dose rate is greater than the alarm judgment value. In processing blocks D and E, an internal program determines whether the value is 90% or more of the maximum value of the range and 8% or less of the maximum value of the range, and the value is 90% of the maximum value of the range.
% but greater than 8%, processing block F displays and outputs the dose rate via analog output section A○, and processing block G issues an alarm to the outside from digital output section DO2 when it is greater than the alarm judgment value. Output.
この線量率の表示および出力、Ｗ報の８力はアナログ出
力部Ａ○、ディジタル出力部ＤＯ２にホールド回路を設
けているので、処理ブロックＦ。The display and output of this dose rate and the 8 outputs of the W report are processed by the processing block F, since a hold circuit is provided in the analog output section A○ and the digital output section DO2.
Ｇの処理を行なわなければ、前回の出力が保持される。If processing G is not performed, the previous output is retained.
また処理ブロックＤ、Ｈの判定で、それぞれ当該レンジ
最大値の９０％以上、当該レンジ最大値の８％以下であ
れば、ブロックＨ，Ｉではそれぞれ１つ上、１つ下のレ
ンジのレンジ切替信号６を前置増幅器３の帰還抵抗５の
レンジ切替リレーＲｙに出力してレンジを１つ上げるか
、レンジを１つ下げてレンジ切替えを行ない、処理ブロ
ックＪではレンジ切替時の線量率の表示および出力。In addition, if the judgment of processing blocks D and H is 90% or more of the maximum value of the range and 8% or less of the maximum value of the range, blocks H and I switch the range one range higher and one lower, respectively. The signal 6 is output to the range switching relay Ry of the feedback resistor 5 of the preamplifier 3 to increase the range by one or decrease the range by one to perform range switching, and processing block J displays the dose rate at the time of range switching. and output.
警報の出力の保持時間τをレンジ切替後のレンジの帰還
抵抗Ｒを用いてコンデンサＣとによる時定数ＣＲの定数
倍（たとえば５倍）として算出し、処理ブロックにでは
実際のレンジ切替後の出力を保持時間τだけ遅延させる
ことにより、レンジ切替前の出力保持を実現する。The holding time τ of the alarm output is calculated as a constant times (for example, 5 times) the time constant CR due to the capacitor C using the feedback resistor R of the range after range switching, and the processing block calculates the actual output after range switching. By delaying by the holding time τ, the output is held before range switching.
第３図は第１図（第２図）の線量率増加時のレンジ切替
動作特性の説明図である。第３図において、放射線検出
器２を照射する放射線の線量率（ｍＲ／ｈ）が時間的に
直線増加する場合には、まず前置増幅器３はレンジ１で
動作して前置増幅器出力信号電圧（Ｖ）が直線増加し、
電圧最大値０９０％のレンジ１からレンジ２へのシンジ
切替点Ｍより前置増幅器３の出力信号電圧はレンジ２の
帰還抵抗Ｒ２による時定数Ｃ−Ｒ２で本来の前置増幅器
３の出力信号電圧値まで低下したのち、さらに線量率の
直線増加にともない前置増幅器出力信号電圧は直線増加
してレンジ２からレンジ３へのレンジ切替点Ｎよりレン
ジ３の帰還抵抗Ｒ３による時定数Ｃ−Ｒ３で低下したの
ち直線増加に戻る。このような前置増幅器３の出力信号
電圧を線形線量率計１の入力電圧信号として（１）式に
よりｕＡ量率の演算を行なうと、レンジ切替点Ｍ。FIG. 3 is an explanatory diagram of the range switching operation characteristics when the dose rate increases in FIG. 1 (FIG. 2). In FIG. 3, when the dose rate (mR/h) of the radiation irradiating the radiation detector 2 increases linearly over time, the preamplifier 3 first operates in range 1 and the preamplifier output signal voltage (V) increases linearly,
From the synge switching point M from range 1 to range 2 where the voltage maximum value is 090%, the output signal voltage of preamplifier 3 becomes the original output signal voltage of preamplifier 3 with time constant C-R2 due to feedback resistor R2 of range 2. After the preamplifier output signal voltage further increases linearly with the linear increase in the dose rate, the preamplifier output signal voltage increases linearly from the range switching point N from range 2 to range 3 with the time constant C-R3 due to the feedback resistor R3 of range 3. After a decline, it returns to a linear increase. If the output signal voltage of the preamplifier 3 is used as the input voltage signal of the linear dose rate meter 1 and the uA dose rate is calculated using equation (1), the range switching point M is calculated.
Ｎの後の前置増幅器出力信号電圧が時定数Ｃ・Ｒ２，Ｃ
−Ｒ３等で低下する領域において異常に高い出力ａ量率
１１の領域が発生する。このため時定数Ｃ−Ｒ２，Ｃ−
Ｒ３等の定数倍（たとえば５倍）の保持時間τだけレン
ジ切替前の出力線量率１２を保持するようにして、異常
な出力線量率１１の出力を防止することができる。The preamplifier output signal voltage after N is the time constant C・R2,C
-A region where the output a quantity rate is abnormally high 11 occurs in the region where the output a decreases at R3 or the like. Therefore, the time constant C-R2,C-
By holding the output dose rate 12 before range switching for a holding time τ that is a constant multiple (for example, 5 times) of R3, etc., it is possible to prevent an abnormal output dose rate 11 from being output.
第４図は第１図（第２図）の線量率減少時のレンジ切替
動作特性の説明図である。第４図において、放射線検出
器２を照射する線量率が時間的に直線減少する場合には
、まず前置増幅器３はたとえばレンジ３で動作して前置
増幅器出力信号電圧（Ｖ）が直線減少し、電圧最大値の
８％のレンジ３からレンジ２へのレンジ切替点Ｐより前
置増幅器の出力電圧はレンジ２の帰還抵抗Ｒ２による時
定数Ｃ−Ｒ２で本来の前置増幅器３の出力信号電圧値ま
で上昇したのち、さらに線量率の直線減少にともない前
置増幅器出力信号電圧は直線減少してレンジ２からレン
ジ１へのレンジ切替点Ｑよりレンジ１の帰還抵抗Ｒ１に
よる時定数Ｃ−Ｒ１で上昇したのち直線減少に戻る。こ
のような前置増幅器３の出力信号電圧を入力電圧信号と
して（１）式により線量率の演算を行なうと、レンジ切
替点Ｐ、Ｑの後の前置増幅器出力信号電圧が時定数Ｃ・
Ｒ２，Ｃ’−Ｒ３等で上昇する領域において異常に低い
出力線量率１１の領域が発生するので、このときも時定
数Ｃ−Ｒ２，Ｃ−Ｒ１等の定数倍（５倍）の保持時間で
だけレンジ切替前の出力線量率１２を保持することによ
り、異常な出力線量率１１の出力を防止することができ
る。FIG. 4 is an explanatory diagram of the range switching operation characteristics when the dose rate decreases in FIG. 1 (FIG. 2). In FIG. 4, when the dose rate irradiating the radiation detector 2 decreases linearly over time, the preamplifier 3 first operates in range 3, for example, and the preamplifier output signal voltage (V) decreases linearly. Then, from the range switching point P from range 3 to range 2, which is 8% of the maximum voltage value, the output voltage of the preamplifier changes to the original output signal of preamplifier 3 with time constant C-R2 due to feedback resistor R2 of range 2. After increasing to the voltage value, the preamplifier output signal voltage further decreases linearly as the dose rate decreases linearly, and from the range switching point Q from range 2 to range 1, the time constant C-R1 due to the feedback resistor R1 of range 1 It rises at , then returns to a linear decrease. When calculating the dose rate using equation (1) using the output signal voltage of the preamplifier 3 as an input voltage signal, the preamplifier output signal voltage after the range switching points P and Q becomes the time constant C.
An area with an abnormally low output dose rate of 11 occurs in the area where R2, C'-R3, etc. increase, so at this time as well, the holding time is set to a constant times (5 times) the time constants C-R2, C-R1, etc. By retaining the output dose rate 12 before range switching, it is possible to prevent an abnormal output dose rate 11 from being output.
以上のように本実施例によれば、線形線量率計１で線量
率が一定値以上または一定値以下になったことをＢ盆率
計内部のプログラムにより判断し、放射線検出器２の微
少電流信号を増幅する増幅器の帰還抵抗を自動的に切替
えて精度よい計測値をうることが可能である。またレン
ジ切替えの判定値を各レンジごとに上のレンジと下のレ
ンジに切替える時の値を別にしてヒステリシスをもたせ
ることによりそれぞれ切替る２つのレンジ間でチャタリ
ングするのを防止できる。また線形線量率計内のプログ
ラムによりレンジ切替時に線量率の計測値をレンジ切替
前の値に一定時間だけ保持することにより、レンジ切替
時に発生する増幅器からの異常な信号による異常な計測
値の誤表示・出力および誤警報出力を防止できる。かつ
レンジ切替時の計測値の保持時間を各レンジごとに上の
レンジと下のレンジに切替える場合の２種の値をそれぞ
れ予め線量率計の記憶部ＭＥＭに格納しておくことによ
り、レンジ切替時の計測値の保持時間を最短にすること
ができる。さらにレンジ切替時の保持時間を増幅器帰還
抵抗の切替えによるサージ等の吸収および増幅器安定化
のために帰還抵抗と並列に設けたコンデンサによる時定
数Ｃ−Ｒの定数倍とすることにより、レンジ切替時の動
作を最適化できる。As described above, according to this embodiment, it is determined by the program inside the B tray rate meter that the dose rate in the linear dose rate meter 1 has become more than a certain value or less than a certain value, and the minute current of the radiation detector 2 is detected. It is possible to obtain highly accurate measurement values by automatically switching the feedback resistance of the amplifier that amplifies the signal. Further, by setting the range switching determination value to be different for each range and providing hysteresis for switching to the upper range and lower range, it is possible to prevent chattering between the two ranges that are respectively switched. In addition, by using a program in the linear dose rate meter to hold the measured dose rate value at the value before the range change for a certain period of time when changing the range, it is possible to prevent errors in the measured value due to abnormal signals from the amplifier that occur when changing the range. Display/output and false alarm output can be prevented. In addition, by storing two types of values for each range in the storage unit MEM of the dose rate meter in advance for switching to the upper range and lower range for each range, range switching is possible. The retention time of the measured value can be minimized. Furthermore, by making the holding time at range switching a constant times the time constant C-R by a capacitor installed in parallel with the feedback resistor to absorb surges and stabilize the amplifier by switching the amplifier feedback resistor, The operation of the system can be optimized.
本発明の自動レンジ切替型線形ａ量率計によれば、レン
ジ切替時の線量率の異常な計測値の表示・出力および誤
警報出力をなくすことができて、精度よい測定を行ない
つつレンジ切替時の応答を高めることができる等の効果
がある。According to the automatic range switching type linear a dose rate meter of the present invention, it is possible to eliminate the display/output of abnormal measurement values of dose rate and false alarm output when switching ranges, and it is possible to switch ranges while performing accurate measurements. This has the effect of increasing the time response.
第１図は本発明による自動レンジ切替型線形線量率計の
一実施例を示す全体構成図、第２図は第１図の処理フロ
ーチャート、第３図は第１図の線量率増加時の動作特性
図、第４図は第１図の線量率減少時の動作特性図である
。
１・・・線形線量率計、２・・・放射線検出器、３・・
・前置増幅器、４・・・増幅器、５・・・帰還抵抗、６
・・・レンジ切替信号、７・・・前置増幅器出力信号、
８・・・電源線、９・・・高低圧ｆｆｉ源、１０・・・
データバス、１１・・・異常出力線量率、１２・・・保
持出力線量率。Fig. 1 is an overall configuration diagram showing an embodiment of an automatic range switching type linear dose rate meter according to the present invention, Fig. 2 is a processing flowchart of Fig. 1, and Fig. 3 is an operation when the dose rate increases as shown in Fig. 1. The characteristic diagram, FIG. 4, is an operational characteristic diagram when the dose rate decreases in FIG. 1...Linear dose rate meter, 2...Radiation detector, 3...
・Preamplifier, 4...Amplifier, 5...Feedback resistor, 6
... Range switching signal, 7... Preamplifier output signal,
8...Power line, 9...High and low voltage ffi source, 10...
Data bus, 11...Abnormal output dose rate, 12...Holding output dose rate.
Claims (1)
適ゲインで増幅して線量率を計測する放射線計測システ
ムにおいて、計測された線量率値により最適レンジを決
定して該レンジに自動的に切り替える手段と、該レンジ
切替時に出力線量率値をレンジ切替前の値に所定時間保
持する手段を設けたことを特徴とする自動レンジ切替型
線形線量率計。 ２、上記微少信号を一定レンジごとに増幅する前置増幅
器の帰還抵抗と並列にコンデンサを設け、上記レンジ切
替時の出力線量率値の保持時間を上記コンデンサ容量と
レンジ切替後の上記帰還抵抗値による時定数の定数倍と
する手段を設けたことを特徴とする特許請求の範囲第１
項記載の自動レンジ切替型線形線量率計。[Claims] 1. In a radiation measurement system that measures a dose rate by amplifying a minute signal from a radiation detector with an optimum gain for each fixed range, the optimum range is determined based on the measured dose rate value and the appropriate range is determined. An automatic range switching type linear dose rate meter comprising: means for automatically switching to a range; and means for holding an output dose rate value at the value before switching the range for a predetermined period of time when switching the range. 2. A capacitor is installed in parallel with the feedback resistor of the preamplifier that amplifies the above-mentioned minute signal for each fixed range, and the holding time of the output dose rate value when changing the range is determined by the capacitance of the above-mentioned capacitor and the above-mentioned feedback resistance value after changing the range. Claim 1 characterized in that a means for multiplying the time constant by a constant is provided.
Automatic range switching type linear dose rate meter as described in Section 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15505186A JPS6311887A (en) | 1986-07-03 | 1986-07-03 | Automatic range change-over type linear dose rate meter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15505186A JPS6311887A (en) | 1986-07-03 | 1986-07-03 | Automatic range change-over type linear dose rate meter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6311887A true JPS6311887A (en) | 1988-01-19 |
| JPH0579150B2 JPH0579150B2 (en) | 1993-11-01 |
Family
ID=15597596
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15505186A Granted JPS6311887A (en) | 1986-07-03 | 1986-07-03 | Automatic range change-over type linear dose rate meter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6311887A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002277593A (en) * | 2001-03-21 | 2002-09-25 | Konica Corp | Logarithmic transformation circuit and radiographic image reader |
| ES2215490A1 (en) * | 2004-04-19 | 2004-10-01 | Jose Maria Rodriguez San Pedro Pico | Radiological protection dose meter support includes radiation alarm with continuous radiation metering |
| CN111111170A (en) * | 2019-12-23 | 2020-05-08 | 黎明职业大学 | Artificial intelligence judgment implementation system and method |
-
1986
- 1986-07-03 JP JP15505186A patent/JPS6311887A/en active Granted
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2002277593A (en) * | 2001-03-21 | 2002-09-25 | Konica Corp | Logarithmic transformation circuit and radiographic image reader |
| ES2215490A1 (en) * | 2004-04-19 | 2004-10-01 | Jose Maria Rodriguez San Pedro Pico | Radiological protection dose meter support includes radiation alarm with continuous radiation metering |
| CN111111170A (en) * | 2019-12-23 | 2020-05-08 | 黎明职业大学 | Artificial intelligence judgment implementation system and method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0579150B2 (en) | 1993-11-01 |
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| EXPY | Cancellation because of completion of term |