Abstract: In a radiation measurement device in which respective wave height values of voltage pulses from a radiation detector are made to correspond to radiation energy values and a count that is the number of the voltage pulses is separately generated for each of a plurality of channels corresponding to the wave height values so that a wave height spectrum is generated and a dose of a radiation that has entered the radiation detector is calculated based on the wave height spectrum, based on a count in at least one channel, out of the plurality of channels, that includes a lower limit within a measurement range for the radiation energy value, a dose is corrected by calculating a portion thereof neglected as what is the same as or smaller than a measurement limit, so that a dose of a radiation that has entered the radiation detector is calculated.

Abstract: A sampling unit that samples a sample gas includes an intake pipe that takes in a sample gas, and a mist/dust elimination unit that eliminates mist produced when steam in a sample gas condenses in the intake pipe and dust, creates a drain including dust, and separates the drain from the sample gas; mist wets fibers loaded therein in a stacked manner so that a water film produced on the surface of the fibers collects dust, and the water film grows to water drops and become drains so that the dust is exhausted and eliminated.

Abstract: A waveform analyzing section analyzes the waveform of a detector signal pulse. A calculation section calculates a count rate from the addition-subtraction accumulated value of an up-down counter, and detects noise intrusion, based on the output from the waveform analyzing section. When noise intrusion has been detected, the addition-subtraction accumulated value for the present calculation cycle is replaced with the value for the previous calculation cycle. When the noise intrusion has stopped, the addition-subtraction accumulated value of the up-down counter is set at the value for a calculation cycle just before the noise intrusion, by an accumulated value setting circuit.

Abstract: To the problem of measurement error becomes larger by superimposing the leakage current to the current signal of the radiation detector, the electric charge integration unit which outputs the sawtooth pulses by the discharge of the detected to charge the radiation is connected to a time of discharging the charge and is a constant current circuit is disconnected during the charge accumulation is provided, between the constant current circuit and the charge integrator, the leakage current of the switching circuit is connected a first backflow cutoff circuit suppresses during charge accumulation, the leakage current compensation circuit connected to an input of the storage unit of charge leakage of the said the first backflow cutoff circuit second backflow cutoff circuit having a second backflow shutoff circuit of one of the backflow cutoff equivalent characteristics current has to be offset in the opposite direction.

Abstract: In order to obtain a dose-rate measuring system that reduces an influence of an electromagnetic induction noise acting around an ionization chamber and a signal converter, a cabinet of the ionization chamber, shields of cables, a cabinet of the signal converter, and a cabinet of a measuring unit are connected in series, and a single-point ground is performed at the measuring unit, and other units except the grounded measuring unit are insulated from the earth, and moreover, a heatproof insulating material having water repellency is coated on a fixed portion of the ionization chamber, whereby the ionization chamber is electrically insulated from a chassis at a fixed side, and the heatproof insulating material having water repellency is coated on a connecting portion of a connector for connecting a cable to another cable, after a waterproof process is performed on the connecting portion by using a bonding tape.

Abstract: A sampling unit that samples a sample gas includes an intake pipe that takes in a sample gas, and a mist/dust elimination unit that eliminates mist produced when steam in a sample gas condenses in the intake pipe and dust, creates a drain including dust, and separates the drain from the sample gas; mist wets fibers loaded therein in a stacked manner so that a water film produced on the surface of the fibers collects dust, and the water film grows to water drops and become drains so that the dust is exhausted and eliminated.

Abstract: A shield has a detector installing hole having a central axis orthogonal to a central axis of a detection tube. A radiation sensor of a columnar scintillation detector to which a low concentration side measurement range within all required measurement ranges is allocated is arranged inside the detector installing hole. An ionization chamber to which a high concentration side measurement range is allocated is arranged side by side in parallel with the detection tube. The measurement range of the columnar scintillation detector and the measurement range of the ionization chamber are adjusted so as to be overlapped with each other.

Abstract: In order to provide a high accuracy radiation dose rate measurement system by good energy characteristics without deteriorating the original energy characteristics of a low dose rate range due to widening range, the dose rate measurement system is composed of: a radiation detector which sends a discrete current pulse having electric charge proportional to incident radiation energy and a DC voltage in which a DC current proportional to the radiation energy is converted; a high voltage power source which supplies a high voltage that operates the radiation detector; and a measurement unit in which the current pulse and the DC voltage are applied from the radiation detector to be converted to a low range dose rate and a high range dose rate respectively, and the low range dose rate and the high range dose rate are switched to be sent depending on the dose rates.

Abstract: A radiation monitoring device comprises a radiation monitor and a test unit for testing the radiation monitor. The radiation monitor includes a radiation detector and a measurement unit. The test unit includes a test pulse generator and a test pulse controller. The measurement unit includes a counter circuit, a computing part that computes a count rate with the standard deviation kept constant, an input switching circuit. When a test mode is selected in the radiation monitor, the test pulse controller changes the repetition frequency of test pulses in a step-function manner to the same repetition frequency of a start count rate specified as reference, replaces a count rate in the computing part at current computing cycle with the start count rate, switches the input switching circuit to the test pulse input at next computing cycle to start the test, and then finishes the test after a predetermined time elapses.

Abstract: A radiation detector outputs an analog pulse for incident radiation, and a signal processing portion is furnished with a wave height measuring function of converting the analog pulse inputted therein to a digital form and then measuring a peak wave height of the analog pulse and a wave height spectrum measuring function of measuring a wave height spectrum on the basis of measured wave height data, computes a dose rate and mean energy on the basis of measured wave height spectral data, and outputs computation results. The signal processing portion computes the dose rate and the mean energy on the basis of the wave height spectral data in a same wave height range on a same time axis. It thus becomes possible to provide accurate information based on which to determine whether a rise in dose rate is contributed by natural radon and thoron or contributed by a reactor facility.

Abstract: In order to obtain a dose-rate measuring system that reduces an influence of an electromagnetic induction noise acting around an ionization chamber and a signal converter, a cabinet of the ionization chamber, shields of cables, a cabinet of the signal converter, and a cabinet of a measuring unit are connected in series, and a single-point ground is performed at the measuring unit, and other units except the grounded measuring unit are insulated from the earth, and moreover, a heatproof insulating material having water repellency is coated on a fixed portion of the ionization chamber, whereby the ionization chamber is electrically insulated from a chassis at a fixed side, and the heatproof insulating material having water repellency is coated on a connecting portion of a connector for connecting a cable to another cable, after a waterproof process is performed on the connecting portion by using a bonding tape.

Abstract: In order to obtain a radiation measurement system in which a shield is reduced in size to achieve reduction in cost and missing measurement is not present in the whole measurement range, and which is good in stability and responsiveness, a radiation detector which is low in measurement range of radiation is arranged in a sample vessel in which a sample gas serving as a radiation measurement object is made to flow; a radiation detector, which is high in measurement range having a measurement range that follows the radiation detector which is low in measurement range of radiation, is arranged outside the sample vessel; and the sample vessel and a plurality of the radiation detectors are surrounded by a shield to shield from environmental radiation.

Abstract: In a radiation monitoring apparatus having a radiation monitor composed of a radiation detector and a measurement section, and a testing apparatus, an accumulated value setting circuit which forcibly sets an accumulated value of an up-down counter of the measurement section is provided, whereby in a test mode, a test is conducted after the accumulated value of the up-down counter is set at a value corresponding to a start count rate by the accumulated value setting circuit.

Abstract: In order to provide a high accuracy radiation dose rate measurement system by good energy characteristics without deteriorating the original energy characteristics of a low dose rate range due to widening range, the dose rate measurement system is composed of: a radiation detector which sends a discrete current pulse having electric charge proportional to incident radiation energy and a DC voltage in which a DC current proportional to the radiation energy is converted; a high voltage power source which supplies a high voltage that operates the radiation detector; and a measurement unit in which the current pulse and the DC voltage are applied from the radiation detector to be converted to a low range dose rate and a high range dose rate respectively, and the low range dose rate and the high range dose rate are switched to be sent depending on the dose rates.

Abstract: In order to obtain a radiation measurement system in which a shield is reduced in size to achieve reduction in cost and missing measurement is not present in the whole measurement range, and which is good in stability and responsiveness, a radiation detector which is low in measurement range of radiation is arranged in a sample vessel in which a sample gas serving as a radiation measurement object is made to flow; a radiation detector, which is high in measurement range having a measurement range that follows the radiation detector which is low in measurement range of radiation, is arranged outside the sample vessel; and the sample vessel and a plurality of the radiation detectors are surrounded by a shield to shield from environmental radiation.

Abstract: A waveform analyzing section analyzes the waveform of a detector signal pulse. A calculation section calculates a count rate from the addition-subtraction accumulated value of an up-down counter, and detects noise intrusion, based on the output from the waveform analyzing section. When noise intrusion has been detected, the addition-subtraction accumulated value for the present calculation cycle is replaced with the value for the previous calculation cycle. When the noise intrusion has stopped, the addition-subtraction accumulated value of the up-down counter is set at the value for a calculation cycle just before the noise intrusion, by an accumulated value setting circuit.

Abstract: In a radiation monitoring apparatus having a radiation monitor composed of a radiation detector and a measurement section, and a testing apparatus, an accumulated value setting circuit which forcibly sets an accumulated value of an up-down counter of the measurement section is provided, whereby in a test mode, a test is conducted after the accumulated value of the up-down counter is set at a value corresponding to a start count rate by the accumulated value setting circuit.

Abstract: A radiation detector outputs an analog pulse for incident radiation, and a signal processing portion is furnished with a wave height measuring function of converting the analog pulse inputted therein to a digital form and then measuring a peak wave height of the analog pulse and a wave height spectrum measuring function of measuring a wave height spectrum on the basis of measured wave height data, computes a dose rate and mean energy on the basis of measured wave height spectral data, and outputs computation results. The signal processing portion computes the dose rate and the mean energy on the basis of the wave height spectral data in a same wave height range on a same time axis. It thus becomes possible to provide accurate information based on which to determine whether a rise in dose rate is contributed by natural radon and thoron or contributed by a reactor facility.

Abstract: A radiation measuring device includes a computing unit that receives an input of a count value of a count portion configured to receive an input of a digital pulse from a pulse height discriminator and count the digital pulse in a fixed cycle and an integrated value of an adder-subtractor accumulation portion configured to add the digital pulse and subtract a feedback pulse and finds a first current rate on the basis of the count value and the integrated value and a second count rate on the basis of the integrated value, so that soundness of the adder-subtractor accumulation portion is diagnosed and outputted by comparing the first count rate with the second count rate. A radiation measuring device of a simple configuration and a diagnosis method thereof enabling a high-accurate self-diagnosis online on the count rate measurement that is the keystone of the radiation measurement can be thus obtained.

Abstract: A radiation measuring device includes a computing unit that receives an input of a count value of a count portion configured to receive an input of a digital pulse from a pulse height discriminator and count the digital pulse in a fixed cycle and an integrated value of an adder-subtractor accumulation portion configured to add the digital pulse and subtract a feedback pulse and finds a first current rate on the basis of the count value and the integrated value and a second count rate on the basis of the integrated value, so that soundness of the adder-subtractor accumulation portion is diagnosed and outputted by comparing the first count rate with the second count rate. A radiation measuring device of a simple configuration and a diagnosis method thereof enabling a high-accurate self-diagnosis online on the count rate measurement that is the keystone of the radiation measurement can be thus obtained.