A method of geophysical exploration in which the intensity of radioactive rays is obtained by measuring the intensity or concentration of radioactive elements by means of special instruments based on the physical properties of radioactive rays. Detection methods include: surface survey, aerial survey, radiation sampling, well logging, gas emission survey, track survey and physical analysis. The main detection items are ionizing radiation and electromagnetic radiation.

Radiation detection includes content

Ionizing radiation is also known as radioactive radiation, this kind of radiation occurs at higher energy, can cause atomic ionization of the surrounding material. In the field of radiation protection, ionizing radiation refers to radiation that produces ion pairs in biological matter. Ionizing radiation can be divided into α, β, γ (X), N and other radiation according to the nature of the composed particles, and the ability of each particle to penetrate the material is different. Sources of ionizing radiation can be radionuclides (both natural and manufactured), nuclear reaction devices such as reactors, colliders, accelerators, nuclear fusion devices, etc., or X-ray machines used for medical diagnosis and treatment.

Electromagnetic radiation is the radiation produced by electromagnetic waves into the surrounding space due to alternating electric and magnetic fields. Such radiation is too low in energy to cause ionization of surrounding matter. Strictly speaking all electrical appliances (including household appliances) will produce electromagnetic radiation, but the real causes pollution of the environment affects human health is some high power communication equipment, such as radar, television and radio transmitters, industrial microwave heater (microwave oven can also have the electromagnetic radiation), radio frequency induction and dielectric heating equipment, high voltage power transmission and transformation equipment, Electromagnetic medical and diagnostic equipment and so on. Because of the different nature of radiation, the mechanism of its action on the human body is also different from that of ionizing radiation. Electromagnetic radiation has near field and far field, it is divided by the distance of one wavelength. The electromagnetic field intensity in the near field is much greater than that in the far field, so it is the key point of monitoring and protection.

Detection of classification

According to the measurement object can be divided into: α measuring instrument, β measuring instrument, γ measuring instrument, N measuring instrument. In addition, due to the different mechanism of interaction between different particles and substances, different sensors are used according to the different particles to be measured, which can be divided into gas, scintillation, semiconductor sensors and so on.

According to the purpose of monitoring, it can be divided into:
1. Particle intensity meter :(total α, total β, total γ, neutrons) is only related to particle number, independent of energy;
2. Dosimeter: mainly refers to radiation, γ, X and neutrons, not only related to the number of particles, but also related to the energy, but can not distinguish which nuclide;
3. Spectrometer :(α, β, γ, x, neutron), distinguish different radionuclides, and can be combined with the built-in database and correct calibration method to determine the intensity and dose of various radionuclides.

According to the monitoring purpose, it is divided into:
1. Entrance detectors :(pedestrians, vehicles, trains, luggage and parcels, goods, containers, etc.) used for entry-exit inspection and quarantine and homeland security;
2. Site (fixed point) dosimeter: used to detect abnormal emissions in the monitoring area, monitor and alarm the dose at the source site;
3. Inspection dosimeter: used for nuclear environment, nuclear safety, searching for radioactive sources and finding special nuclear materials;
4. Personal dose alarm device: used for personal dose monitoring and alarm of nuclear safety and anti-terrorism personnel;
5. Nuclide identification instrument: used to identify the types of radioactive isotopes and special nuclear materials and determine their strength, it can be divided into laboratory and portable two kinds;
6. Nuclear waste monitor: used in nuclear facilities, nuclear power plants, etc., to monitor and classify nuclear waste;
7. Surface pollution monitor: it has the ability to monitor the surface of road (vehicle-mounted), whole body and work clothes (fixed), desktop or local surface of any work area (portable);
8. Gas and aerosol measuring instrument: radon, thorium emission, Xe and other inert gases;

9. Effluent monitoring system: used in nuclear power plants and other large nuclear facilities;
10. Nuclear imaging system: large nuclear instruments use a combination of radiation sources and sensors to scan and image the monitoring target;
11. Other auxiliary facilities: such as automatic weather station, aerosol sampling equipment, radio positioning system, vehicle equipment, etc.

2. Certification services

The test report issued by Global Zhongyi has legal effect and can be used in scenarios such as the entry of supermarkets, product appeals, anti-malicious rights protection, and auctions (appeals and auctions must meet Party A's testing requirements).