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公开(公告)号：JPH06258450A
公开(公告)日：1994-09-16
申请号：JP4940493
申请日：1993-03-10
Applicant: ALOKA CO LTD
Inventor： MITO MASAYASU , SATO HIROO , ONO TAKESHI
Abstract: PURPOSE:To provide a downsized radiation measuring equipment for measuring radon and thoron existing in a gas with high sensitivity. CONSTITUTION:A container 32 for an ionization chamber 30 is composed of an alpha-ray transmitting material and an ionization gas is encapsulated therein. The container 32 is made of an organic film, for example, and a frame 44 is provided in order to hold the container 32. A conductive coating material 46 is applied to the inner face of the container 32 and a voltage is applied between the coating material 46 and a current collecting electrode 34. Since the container 32 is entirely composed of an alpha-ray transmitting material, radon existing around the container can be measured efficiently.
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公开(公告)号：JPH0553385B2
公开(公告)日：1993-08-09
申请号：JP19557989
申请日：1989-07-28
Applicant: ALOKA CO LTD
Inventor： SATO HIROO , MITO MASAYASU
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公开(公告)号：JPH0551111B2
公开(公告)日：1993-07-30
申请号：JP30352486
申请日：1986-12-18
Applicant: ALOKA CO LTD
Inventor： OOWAKI SHIGEHIRO , SATO HIROO , MITO MASAYASU , MAEKAWA HIROSHI
IPC: G01T1/167
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公开(公告)号：JPH0420894A
公开(公告)日：1992-01-24
申请号：JP12644390
申请日：1990-05-16
Applicant: ALOKA CO LTD
Inventor： SATO HIROO , MITO MASAYASU
IPC: G01T3/00
Abstract: PURPOSE:To enable accurate measurement in wide range of energy region weighted appropriately by providing an ion chamber part having a pair of ion chamber loaded on a human body side and on outside of the human body, an electric source, a neutron filter and an arithmetic means. CONSTITUTION:A neutron equivalent dosimeter is loaded on a human body 26. If thermal neutrons 100 are irradiated from outside, these thermal neutrons 100 go into a second ion chamber 10-2 on the other side of the body and react here to produce alpha ray which causes ionization. Due to this ionization, electrons reach a collecting electrode and resulting pulse is counted by a counter. On the other hand, if medium and fast neutrons 200 are irradiated from outside and they go into the ion chamber 10-2, the medium and fast neutrons having high energy pass the ion chamber 10-2 due to very small reaction cross section area for 10B. Furthermore, the neutrons 200 pass through a neutron filter 14 and an ion chamber 10-2 as they are to go into the human body 26. The neutrons 200 having reached the human body 26 are scattered in the human body 26 to be thermal neutrons 300, go out of the human body and again go into the ion chamber 10-1.
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公开(公告)号：JPS63315974A
公开(公告)日：1988-12-23
申请号：JP15253787
申请日：1987-06-19
Applicant: ALOKA CO LTD
Inventor： SATO HIROO , MITO MASAYASU
Abstract: PURPOSE:To efficiently measure a radiation ray of low energy by adsorbing tritium converted to tritium water, by a collecting plate being a part of a detector. CONSTITUTION:A portable pocket dosimeter for opening a Lauritsen foil detecting electrode 18 consisting of two sheets of a electrode foils of the rear end part of a rod-like electrode 12 by an ionization charge detected by a detecting part 10, and measuring the radioactive concentration by its degree is provided with a converting container 22 provided with a catalyst 22a of platinum and palladium, etc. on the inner wall, a lead-in part 24 for leading in measured air containing tritium water being steam and other radioactive substance, and a collecting plate 26 for adsorbing and collecting the radioactive substance and consisting of such materials as molecular sieve, silica gel, activated carbon, etc. On the detecting surface side of the collecting plate 26, a mesh- like cathode plate 10b is provided. In such a way, a portable personal monitor which can measure exactly a radiant ray of low energy can be offered.
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Patent Agency Ranking
公开(公告)号：JPS6214079A
公开(公告)日：1987-01-22
申请号：JP15127185
申请日：1985-07-11
Applicant: ALOKA CO LTD
Inventor： MITO MASAYASU , MAEKAWA HIROSHI
Abstract: PURPOSE:To enable the maintaining of the permeation rate of tritium with a permeation membrane at a constant level, by humidifying a purge gas prior to the introduction thereof into a membrane separator to prevent the drying of the permeation membrane irrelevant to humidity of air to be detected. CONSTITUTION:A purge gas 200 is humidified with a humidifier 54 comprising a water bubbler 50 and a water bath 52 before the introduction thereof into a membrane separator 10. Then, the gas 200 bubbles in the bubbler 50 is raised to 100% in the relative humidity and fed into the separator 10 from a take off port 24 through a flowmeter 44. Here, the temperature of the gas 200 is adjusted with a bath 52 or the like to be maintained at the temperature of a measuring device so that the dew formation of the gas 200 may be prevented in the measuring device. Thus, a permeation membrane can be wetted sufficiently for the passage of the gas 200 thereby permitting tritium water in air 100 to be detected to permeate to a purge gas path efficiently through the permeation membrane when passing through an detecting air path.
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公开(公告)号：JPS61280591A
公开(公告)日：1986-12-11
申请号：JP27644384
申请日：1984-12-28
Applicant: ALOKA CO LTD , ASAHI CHEMICAL IND
Inventor： MITO MASAYASU , MAEKAWA HIROSHI , EBISAWA MIKIO , KAGEURA YOSHIAKI
Abstract: PURPOSE:To automatically equalize the kinds and pressures of gases in both ionization boxes for compensation and measurement even if the kind and pressure of purge gas to be used changes and to facilitate the handling of concn. measurement, by allowing purge gas before flowing into a purge gas passage to pass through the compensation ionization box. CONSTITUTION:Air 100 to be detected is passed through a membrane separator 10 and tritium water in the air 100 to be detected is taken in the purge gas 200 sent into the membrane separator 10 to measure the concn. of tritium. Take-in ports and take-out ports of purge gas 200 are respectively provided to both of the measuring ionization box 48 and compensation ionization box 50 of a measuring device and the purge gas supplied from a gas bomb 40 passes through the compensation ionization box 50 to enter the membrane separator 10 and, therefore, even if the gas bomb 40 is replaced or the kind or pressure of the purge gas 200 is changed, the kinds and pressures of the gases in both ionization boxes 48, 50 become automatically equal and handling becomes easy and the concn. of tritium can be accurately measured.
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公开(公告)号：JPH06258443A
公开(公告)日：1994-09-16
申请号：JP4929993
申请日：1993-03-10
Applicant: ALOKA CO LTD
Inventor： ONO TAKESHI , MITO MASAYASU , SATO HIROO
Abstract: PURPOSE:To measure radioactive elements in a gas efficiently by providing an adsorptive substance in an ionization chamber. CONSTITUTION:Air is sucked into a dust filter 10 where relatively large dusts are removed. An ionization chamber 30 comprises an adsorptive substance 32 arranged on the inner surface thereat, a meshed electrode 33 arranged farther inside, and a current collecting electrode 34, wherein a high voltage is applied between the electrodes from a DC power supply 22. A pump 16 produces a negative pressure in the ionization chamber 30 and the air passed through the ionization chamber 30 is discharged to the outside by means of the pump 16. When atoms of the gas are ionized by alpha-rays emitted from radon, electrons are captured by the current collecting electrode 34 which feeds a current to a vibrating capacitor electrometer head 24 where the signal is amplified and further amplified by a charged current amplifier 36 before it is recorded in a recorder 28.
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公开(公告)号：JPH0579952B2
公开(公告)日：1993-11-05
申请号：JP10559588
申请日：1988-04-28
Applicant: ALOKA CO LTD
Inventor： SATO HIROO , MITO MASAYASU
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公开(公告)号：JPH05209965A
公开(公告)日：1993-08-20
申请号：JP1550392
申请日：1992-01-30
Applicant: ALOKA CO LTD
Inventor： ONO TAKESHI , MITO MASAYASU , SATO HIROO
Abstract: PURPOSE:To easily and quickly obtain the density of beta nuclides for each type thereof by finding a real peak value via the correction of the measured peak value of each nuclide available from judgement about a beta ray spectrum detected and prepared from a sample. CONSTITUTION:An arithmetic circuit 24 prepares the measured spectrum of betarays detected with a detecting section 10 and, for example, retrieves the peak value of each of H, C and P. Also, measured peak values are identified for each of the peak values and stored in a data memory. At the same time, the circuit 24 identifies the type of a nuclide contained in a sample on the basis of each measured value, and deducts the mutual contribution factors of nuclides from each measured peak value, while assuming a spectrum for each identified nuclide. Real peak values are thereby computed. Furthermore, respective real peak values are multiplied by the inverse number of counting efficiency, thereby obtaining the accurate density of each type of nuclide.
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