A device for measuring radiation: the title, description dosimeters
Devices for measurement of background radiation: types and properties
The background radiation of the environment are constantly present in human life. Daily exposure to some extent has a negative influence on health in the form of violations of protective functions of the organism, development of malignant tumors, etc. the Modern world is rich with sources of radiation, so ordinary people often wonder how to measure the radiation level? A device for measuring radiation called dosimeter. Let us consider all of its features.
How does a device for measuring radioactivity
The most popular device for measuring radiation is the Geiger counter, the name of which becomes clear about its founder. The device was created by German physicist Hans Geiger in 1908, together with another scientist named Ernest Rutherford. Two decades later, physicist resumed the invention of the counter, using his physicist Muller. The unit for more than a century, but its popularity is not falling in the modern world.
The primary component is a sealed cylinder of glass or metal, which is filled with argon and neon. Additionally, this capacity is added to the two electrodes. Radiation extends the wave by the particles. When you hit the smallest part in the sensor, a mixture of gas begins to ionize, the gas atoms are charged and can light up from it. The whole process is controlled by the device.
The sensor captures this process. To register precise quantities of radioactive components, the ionization is extinguished artificial method in seconds. The counter emits a click when the presence of radioactive particles. The radiation level can be measured in many ways. In addition to sensor, applied scintillation crystals that allow you to find specific substances by their characteristic radiation.
Photomultiplier tube records the number of flashes, the number of which depends on the radiation dose.
Types of dosimeters
Instruments for measuring radiation are divided into several types according to their operating conditions and destination:
- Household. This device can measure radiation in the domestic environment, but they have a high level of uncertainty. They help to measure the total background radiation in the building or in the food, but the devices capture only the gamma waves. Some models are equipped with additional sensors for recording of alpha — and beta-radiation.
- Professional. The dosimeters have a broad spectrum of action, measuring the radiation inside and outside. The device can only detect radionuclides, which are in different substances, objects and even living tissues. Built-in sensor detects radiation from neutrons, protons.
- Individual. The dosimeter registers the accumulated level of radiation exposure. Often done in the form of a wristwatch.
- Industrial. Such devices are placed directly near the radiation sources in order to regularly control and monitor the level of exposure.
- Military. The unit is used in the period of hostilities, including operation in the center of a nuclear explosion.
As happens with exposure to radiation
People are able to get harmful radiation in two ways:
- When a nuclear explosion occurs deposition of components from the cloud of the explosion and radiation, which is due to the appearance of spontaneous decay of the isotopes under the influence of gamma and fast neutron radiation of a nuclear explosion. This has a negative effect on humans and animals due to internal and external gamma irradiation in contact with the body of a living being through food, water or air.
- In the technogenic accidents (improper storage of radioactive waste leakage in reactors, leakage from different sources) due to dispersion of harmful components. By type of failure can be judged about the nature of the infection.
Measurement of radiation in everyday life
Device for measuring radiation and radiation need not only people who have the attitude towards peaceful atom, because it is often used in the home.
Dosimeter used to measure the level of radioactive substances in materials of construction or in ordinary foods. Sometimes the device checks the ground before building on it the building or home.
Basically the appliance has a small size and has a display which shows you the level of radiation. This unit can be both non-threshold and threshold.
Threshold dosimeters alert sound signal about exceeding of permissible radioactive level, preset by the manufacturer. This option is easier to use, and the cost relatively lower. Non-threshold device indicates that a certain radiation level, all the levels be set by a user manually. A device for measuring the level of radiation of this type is designed for professionals who know what the occasion is characteristic of a particular exposure.
The effect of radiation on human
Irradiation is the process of exposure to radiation rays on the human body through the transfer of harmful energy to the cells. This influence contributes to metabolic disorder and the development of leukemia, cancer, infertility, burns, cataracts and infectious diseases with complications. Side effects of radiation affects dividing cells, so radiation is much more dangerous for children than adults. Prohibited for pregnant women to be under the influence of radioactive substances in order to avoid negative consequences for the unborn child.
There are four main stages of radiation disease in an acute form: easy (of 0.1-0.2 SV), medium (0,2-0,4 SV), heavy (of 0.4-0.6 SV) and extremely severe (above 0.6 SV). If the exposure is less than 0.1 SV, it is radiation injury.
Everyone should know the rate of radiation, which ranges from 0 to 0.2 Μsv/h, or from 0 to 20 Mr/HR. Level of radiation is measured in Sieverts. Key indicators of exposure and examples:
- 0,22 Μsv/h the standard dose of radiation, which affect all of humanity in everyday life;
- Of 1.00 MSv/h radiation get passengers on the plane, fly from China to USA over the North pole.
- Of 2.28 Μsv/h – the average dosage of radiation for people working in the nuclear industry;
- Of 11.42 Μsv/h under such a strong influence, increasing the chance of cancer;
- 40,00 MSv on a continuous basis – the need to evacuate after the Chernobyl disaster;
- 114,14 Μsv/ times – developing radiation disease characterized by a decrease in the level of white cells in human blood and nausea;
- 570,77 Μsv/ times – 50% of radiation of people die within one month after exposure.
Before you purchase the device, it should be understood that the control dosimeters of gamma-radiation, and radiometers of alpha – and beta-radiation. There are versatile instruments, combining as dosimeter and radiometer. It is considered the most popular household dosimeter, which is selected by referring to the displayed radiation, the measurement time, the meter, the uncertainty of cost, weight, size, and type of manufacturing:
- A capture unit. This element is embedded in the body of the measuring device, although in some models it is located in a separate building. It is based on discharge probe or a scintillation crystal. The first option is easy to use and low cost. Crystals are glued with special glue to the photodiodes, so replacement takes place in the factory.
- The duration of the work. Basically, the measurement time is 20-40 seconds, but the preparation will take approximately 5 minutes. More expensive models are faster reads radiation levels.
- The degree of error. This parameter is very important for low backgrounds. The standard device used to measure radiation, has a margin of error of 15%. Often when the temperature drops, the instrument shows incorrect information on the display, and sometimes even the two sides. If it will be used throughout the year, it is better to give preference to the hardy mind, though its price will increase by 10%. Also pay attention to dust — and moisture-resistant option that you can take with you anywhere, without fear for his health.
Radiation to see without a special device it is impossible, although adverse effects after irradiation occur almost instantly. If there is a suspicion that the background radiation can be upgraded, you should buy a special dosimeter. It is used for inspections of radiation facilities, food, different materials.