{"id":7905,"date":"2025-04-27T13:07:11","date_gmt":"2025-04-27T04:07:11","guid":{"rendered":"https:\/\/www.envraddb.go.jp\/entesttest\/?page_id=7905"},"modified":"2026-06-08T06:50:00","modified_gmt":"2026-06-07T21:50:00","slug":"measurement","status":"publish","type":"page","link":"https:\/\/www.envraddb.go.jp\/en\/special\/measurement\/","title":{"rendered":"Basics of Environmental Radioactivity and Radiation Measurement"},"content":{"rendered":"<main>\r\n  <div class=\"general-content l-mt48\">\r\n    <div class=\"general-content__inner\">\r\n      <p class=\"general-content__text l-mt20\">\r\n     How to collect and pretreat analytical samples for the Environmental Radioactivity Survey, and how to measure environmental radioactivity and radiation are explained.\r\n      <\/p>\r\n\r\n      <section>\r\n        <h3 class=\"underline-ttl\">Collection and Pretreatment of Samples<\/h3>\r\n        <ul class=\"underline__list\">\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>1<\/span>Collection of airborne dust\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Airborne dust is collected by sucking in 10,000m<sup>3<\/sup> of air over a period of 3 months using a\r\n                high-volume air sampler, four times a year (April to June, July to September, October to December, and\r\n                January to March). The filter used is HE-40T, etc. The air intake opening of the high-volume air sampler\r\n                is placed at a height of 1 m from the ground.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_1.jpg\" alt=\"High-Volume Air Sampler\" width=\"260\" \/>\r\n                <p>High-Volume Air Sampler<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>2<\/span>Collection and pretreatment of fallout\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                For fallout (rainwater, dust, etc.), a large basin (water receiving surface area: approx.\r\n                5,000cm<sup>2<\/sup>) having pure water to a depth greater than 1 cm is placed at the beginning of each\r\n                month (12 times a year) to receive fallout for the month.<br>\r\n                At the end of the month, the collected fallout sample is transferred to a polyethylene bucket, and dust\r\n                attached to the basin is scraped off using a rubber scraper and added to the fallout sample. The sample\r\n                is then placed in an evaporating dish or beaker in appropriate quantities, heated to evaporate and\r\n                concentrate, transferred to a measurement container and further heated to dryness using an infrared\r\n                lamp, and the residue is used for analysis.\r\n\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_2.jpg\" alt=\"Large stainless-steel basin\" width=\"260\" \/>\r\n                <p>Large stainless-steel basin<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>3<\/span>Collection and pretreatment of inland water (clean water, fresh water, etc.)\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Clean water (source water or tap water) is sampled once a year in June. Source water is collected from\r\n                the center of the water intake or a source water tap of water purification plants, and tap water is\r\n                collected from household taps. Fresh water such as lake water is sampled once a year, in which the\r\n                surface water is collected from the center of the lake avoiding near inflows from and outflows to\r\n                rivers. The collection volume is 100 L each for clean water and fresh water. The sample is then placed\r\n                in an evaporating dish or beaker in appropriate quantities, heated to evaporate and concentrate,\r\n                transferred to a measurement container and further heated to dryness using an infrared lamp, and the\r\n                residue is used for analysis.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_3.jpg\" alt=\"Collecting tap water\" width=\"260\" \/>\r\n                <p>Collecting tap water<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>4<\/span>Collection and pretreatment of soil (0-5 cm, 5-20 cm)\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Soil is collected once a year, around the end of the rainy season. The sampling location shall be\r\n                selected in an undisturbed area within a relatively large and flat region that represents the\r\n                surrounding area. A soil sampler with an inner diameter of 5-8 cm is hammered into the ground surface to\r\n                first collect 2-4 kg of the soil in the surface layer (0-5 cm) and then 6-12 kg of soil in the deeper\r\n                layer (5-20 cm). The collected samples are fully dried using a drying oven controlled at a temperature\r\n                of about 105\u00b0C, and then crushed and used for analysis.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_4.jpg\" alt=\"Collecting soil\" width=\"260\" \/>\r\n                <p>Collecting soil<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>5<\/span>Collection and pretreatment of sea sediment\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Sea sediment is collected once a year (in July or August), at a location with a water depth of more than\r\n                1 m at low tide and with little movement of sea sediment, using an Ekman-Birge or plane type mud\r\n                collector. The amount to collect is 4 kg. The collected samples are treated by leaving them to stand and\r\n                removing the supernatant or filtering using a large Buchner funnel, spread on an enamel or stainless\r\n                steel vat, fully dried using a drying oven controlled at a temperature of about 105\u00b0C, and then crushed\r\n                and used for analysis.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_5.jpg\" alt=\"Mud collector\" width=\"260\" \/>\r\n                <p>Mud collector<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>6<\/span>Collection of white rice\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              White rice is obtained once a year, during the harvest season. The collected amount is about 3 kg, and\r\n              only those with identifiable production regions are collected.\r\n            <\/p>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>7<\/span>Collection and pretreatment of vegetables\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              Vegetables are obtained once a year, during the harvest season. The collected amount is about 4 kg, and\r\n              only those with identifiable production regions are collected. Parts usually not consumed (e.g., roots)\r\n              and rotten sections are not included in the sample. The sample is placed in a ceramic evaporating dish,\r\n              either slowly carbonized using a gas burner or electric heater, or, dried using a drying oven, then placed\r\n              in an electric furnace and incinerated at a temperature of 450\u00b0C for about 24 hours, and used for\r\n              analysis.\r\n            <\/p>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>8<\/span>Collection and pretreatment of tea leaves\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              Tea leaves are obtained once a year, during the first tea picking season. The collected amount is about\r\n              500 g, and unprocessed or processed tea with known production regions and collecting periods are obtained\r\n              from a production plant, etc. The sample is placed in a ceramic evaporating dish, either slowly carbonized\r\n              using a gas burner or electric heater, or, dried using a drying oven, then placed in an electric furnace\r\n              and incinerated at a temperature of 450\u00b0C for about 24 hours, and used for analysis.\r\n            <\/p>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>9<\/span>Collection of milk\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              Milk is obtained once a year, in June. The collected amount is about 3 kg, and domestically produced milk\r\n              with identifiable production regions is collected.\r\n            <\/p>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>10<\/span>Collection of sea water\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              Sea water is collected once a year (in July or August), avoiding areas into which river water flows.\r\n              Approximately 40 L of sea water is collected from the sea surface using a polyethylene bucket, and placed\r\n              in a polyethylene container.\r\n            <\/p>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>11<\/span>Acquisition and sample preparation (including pretreatment) for aquatic products (fishes,\r\n                shellfishes, and algae)\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Aquatic products are obtained once a year, taking into account their seasons. The type and sampling\r\n                location of aquatic products are selected from the viewpoint of the appropriateness to be surveyed, such\r\n                as the importance in terms of fisheries business (e.g., large catch) and the length of stay in the\r\n                relevant waters (fishing grounds), and samples with identified collected waters are acquired. The\r\n                collected amount is about 4 kg for fishes, 4-5 kg for shellfishes, and 2-3 kg for algae. Obtained\r\n                samples are first washed with water, dried using filter paper, etc., and pretreated (e.g., deboning and\r\n                gutting for large fish (small fish is used as is), removing shells from shellfish, and removing root\r\n                from algae). Pretreated samples are placed in a ceramic evaporating dish, dried by heating for a long\r\n                period of time using a gas burner or electric heater or by using a drying oven, incinerated in an\r\n                electric furnace at a temperature of about 450\u00b0C for about 24 hours, and used for analysis.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_6.jpg\" alt=\"Pretreating fish\" width=\"260\" \/>\r\n                <p>Pretreating fish<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>12<\/span>Collection and pretreatment of daily food\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              Daily food is collected twice a year, in June and in November and December. One serving of normal meals\r\n              (breakfast, lunch, dinner and snacks) for one day is gathered in large polyethylene jars from five\r\n              households. Parts not consumed, such as fish bones and soy pods, are removed from the collected samples.\r\n              Since daily food includes drinking water and other beverages, it is heated to remove moisture. The samples\r\n              are further dried in a drying oven controlled at a temperature of 105\u00b0C, incinerated in an electric oven\r\n              (450\u00b0C, about 24 hours), and the incineration residue is used for analysis.\r\n            <\/p>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>13<\/span>Collection and pretreatment of fixed time rainfall\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text\">\r\n              <p>\r\n                Fixed time rainfall is to collect rain that has fallen in the preceding 24 hours at a fixed time\r\n                (usually 9:00 am) every day and to measure the average radioactivity concentration. Samples are\r\n                collected using a 70A-H radioactive precipitation collector or other similar equipment. Collected\r\n                samples are mixed well, and then the volume is measured using a graduated cylinder. When the collected\r\n                volume is 100 ml or less, the entire amount is used for analysis. When the collected volume is more than\r\n                100 ml, 100 ml is separated and used for analysis. The sample is placed in an evaporating dish or\r\n                beaker, evaporated to concentrate, heated to dryness using an electric heater or infrared lamp, and the\r\n                residue is measured using a low-background beta counter.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/en\/special\/measurement_7-en.png\" alt=\"\u9664\u67d3\u306e\u30a4\u30e9\u30b9\u30c8\"\r\n                  style=\"margin-top: 1rem; width: 100%\" \/>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n        <\/ul>\r\n      <\/section>\r\n\r\n      <section>\r\n        <h3 class=\"underline-ttl\">Environmental Radioactivity Analysis and Environmental Radiation Measurement<\/h3>\r\n        <ul class=\"underline__list\">\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>1<\/span>Radiochemical analysis of Sr-90\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                The analysis sample is decomposed using nitric acid, etc., to make into a solution. Carbonate\r\n                precipitate (which contains Sr-90) is formed to separate Sr-90 from Cs-137. Sr-90 contained in the\r\n                precipitate is separated from other metals such as calcium using the ion exchange resin method. At the\r\n                time of radioactivity measurement, Y-90 generated from Sr-90 is separated and refined, and the\r\n                radioactivity of Y-90 is measured using a low-background beta counter.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_8.jpg\" alt=\"Sr-Radiochemical analysis of Sr-90\"\r\n                  width=\"260\" \/>\r\n                <p>Sr-Radiochemical analysis of Sr-90<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>2<\/span>Radiochemical analysis of Cs-137\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                The analysis sample is decomposed using nitric acid, etc., to make into a solution, and carbonate\r\n                precipitate is formed. The precipitate is used for the analysis of Sr-90. Cs-137 in the supernatant is\r\n                adsorbed to ammonium phosphomolybdate, and separated and refined using the ion exchange resin method.\r\n                Precipitate of cesium chloroplatinate is formed, and its radioactivity is measured using a\r\n                low-background beta counter.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_9.jpg\" alt=\"Radiochemical analysis of Cs-137\"\r\n                  width=\"260\" \/>\r\n                <p>Radiochemical analysis of Cs-137<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>3<\/span>Air radiation dose rate measurement (measurement at monitoring posts)\r\n              <\/p>\r\n            <\/div>\r\n            <p class=\"underline__list__item__a general-content__text\">\r\n              Air radiation dose rates are continuously measured using a NaI(Tl) scintillation monitor. A radiation\r\n              detector is generally installed at a height of 1 meter above the ground. On this website, the current\r\n              environmental radiation levels (10-minute values) are shown on the <a href=\"https:\/\/www.envraddb.go.jp\/en\/general\/adrmap1\/\"\r\n                target=\"_blank\" rel=\"noopener noreferrer\">Current Environmental Radiation Levels page<\/a>, and the daily\r\n              maximum, minimum, and average values are available on the <a href=\"https:\/\/www.envraddb.go.jp\/en\/special\/database\/\"\r\n                target=\"_blank\" rel=\"noopener noreferrer\">Environmental Radiation Database page.<\/a>\r\n            <\/p>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>4<\/span>Air radiation dose rate measurement (measurement using survey meter)\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Air absorbed dose rates (\u03bcGy\/h) are measured using NaI(Tl) scintillation survey meters (portable simple\r\n                measurement equipment). The radiation detector part is held in a horizontal orientation at a height of 1\r\n                m from the ground surface, measured values are read several times at an interval of 10-30 seconds, and\r\n                an average is derived from the readings.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_10.jpg\"\r\n                  alt=\"Air radiation dose rate measurement (measurement using survey meter)\" width=\"260\" \/>\r\n                <p>Air radiation dose rate measurement <br \/>(measurement using survey meter)<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n          <!-- \u753b\u50cf\u3042\u308a -->\r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>5<\/span>Radon measurement\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n                Radon concentration measurement equipment is placed at a measuring position for three months. Airborne\r\n                radon (Rn-222) that entered into the measurement equipment decays and releases \u03b1-rays, and the \u03b1-rays\r\n                leave traces of their flight (extremely minute scar-like traces; called \u03b1-track) on a polycarbonate\r\n                measurement film. The tracks are enlarged by chemical treatment, the number of the tracks is counted\r\n                under observation of an optical microscope, and the radon concentration is derived.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_11.jpg\" alt=\"\u30e9\u30c9\u30f3\u6fc3\u5ea6\u6e2c\u5b9a\u5668\u306e\u5199\u771f\" width=\"260\" \/>\r\n                <p>Radon concentration measurement equipment<\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n      \r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>6<\/span>Gamma (\u03b3)-Ray Spectrometry\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n               By measuring emitted gamma (\u03b3) rays using instruments such as a germanium semiconductor detector, the amount of gamma (\u03b3)-ray-emitting nuclides contained in a sample can be determined. In principle, no pretreatment to separate interfering substances is required. The sample is cut into small pieces or ashed, packed into a measurement container, and then measured using a germanium semiconductor detector or similar instrumentation.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n       \r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_12_en.png\" alt=\"germanium semiconductor detector\" width=\"260\" \/>\r\n                <p>Germanium semiconductor detector\r\n                <\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n\r\n   \r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>7<\/span>Alpha (\u03b1)-Ray Spectrometry\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\n              Due to their low penetrating power, alpha (\u03b1)-rays are easily blocked by other substances, making it difficult to obtain accurate measurements through direct analysis. Therefore, pretreatment is required to separate interfering substances prior to measurement. As part of this process, separation is carried out using methods such as ion-exchange chromatography. Subsequently, electrodeposition\u2014applying an electric current to plate the sample onto a stainless-steel plate\u2014is performed to prepare the source. By preparing the sample as an extremely thin layer on the plate, the self-absorption of alpha (\u03b1)-rays within the sample can be minimized. Furthermore, to prevent alpha  (\u03b1)-rays from being absorbed by air, the sample is placed in a vacuum chamber and measured using an alpha (\u03b1)-ray spectrometer.\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n               \r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_13.png\" alt=\"Alpha (\u03b1)-Ray Spectrometry\" width=\"260\" \/>\r\n                <p>Alpha (\u03b1)-Ray Spectrometry\r\n\r\n                <\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n\r\n         \r\n          <li class=\"underline__list__item\">\r\n            <div class=\"underline__list__item__q\">\r\n              <p class=\"underline__list__item__q__ttl\">\r\n                <span>8<\/span>Liquid Scintillation Counting (LSC)\r\n              <\/p>\r\n            <\/div>\r\n            <div class=\"underline__list__item__a general-content__text underline__list__item__flex-box\">\r\n              <p>\r\nA sample containing beta (\u03b2)-ray-emitting radionuclides is mixed with a liquid scintillator, which converts the energy of the beta (\u03b2)-rays into light. The light emitted from the mixture is then measured using a liquid scintillation counter.\r\n\r\n              <\/p>\r\n              <div class=\"underline__list__item__flex-box__img\">\r\n          \r\n                <img decoding=\"async\" src=\"\/common\/images\/knowledge\/knowledge_14.png\" alt=\"Liquid Scintillation Counting\" width=\"260\" \/>\r\n                <p>Liquid Scintillation Counting\r\n                <\/p>\r\n              <\/div>\r\n            <\/div>\r\n          <\/li>\r\n        <\/ul>\r\n\r\n      <\/section>\r\n\r\n      <ul class=\"single-series-btn-list jc-center\">\r\n        <li class=\"btnMove\">\r\n          <a href=\"https:\/\/www.envraddb.go.jp\/en\/\" class=\"btn\">Return to Home<\/a>\r\n        <\/li>\r\n      <\/ul>\r\n\r\n    <\/div>\r\n\r\n  <\/div>\r\n<\/main>","protected":false},"excerpt":{"rendered":"How to collect and pretreat analytical samples for the Environmental Radioactivity Survey, and how to measure  [&hellip;]","protected":false},"author":1,"featured_media":0,"parent":7729,"menu_order":24,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"footnotes":""},"page_category":[],"class_list":["post-7905","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/pages\/7905","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/comments?post=7905"}],"version-history":[{"count":14,"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/pages\/7905\/revisions"}],"predecessor-version":[{"id":9221,"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/pages\/7905\/revisions\/9221"}],"up":[{"embeddable":true,"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/pages\/7729"}],"wp:attachment":[{"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/media?parent=7905"}],"wp:term":[{"taxonomy":"page_category","embeddable":true,"href":"https:\/\/www.envraddb.go.jp\/en\/wp-json\/wp\/v2\/page_category?post=7905"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}