blog.uaid.net.ua
A dosimeter is a device whose principle of operation is to identify sources of increased radiation and signal a violation. In our article, we will describe in detail where the device is used to measure radioactive radiation and how to choose it.
The content of the article
- How the dosimeter works: its design
- Why buy a device that measures radiation
- What is a dosimeter and how to choose it when you don’t know what and where to look
How the dosimeter works: its design
Each dosimeter works in the same way. The basic element in the design is a radiation sensor. According to the principle of its operation, sensors can be divided into:
- Ionization - consists of gas-filled chambers. When passing through the chamber, negative particles ionize the gas, causing irritation. They are fixed in the device and displayed on the scoreboard. Such instruments are used to measure gamma and beta radiation. Doesn't work well with alpha radiation. A common design of a gas discharge dosimeter is a Geiger-Muller counter.
- Scintillation crystals - based on organic or inorganic material. If charged particles pass through the crystal, then this surge is recorded by the device, displaying it on the scoreboard. Used in search operations. Expensive and very heavy.
- Semiconductor sensors - consist of a crystal and a semiconductor. The action is based on changes in the conductivity of the material when charged particles hit it. Used to detect all types of radiation. The low cost and small size completely cover the slight measurement error.
Now you know the name of the device for measuring radiation, depending on the built-in sensor. Next, let's talk about the criteria for choosing a radiation meter.
Why buy a device that measures radiation
For domestic purposes - an individual solution. But even in everyday life there are situations when you simply cannot do without a dosimeter. For example, you are walking through the woods and you see an ordinary-looking nail. Where he came from is unknown.
Even a couple of minutes near such a nail can lead to great negative consequences if it is exposed to radiation. Therefore, even walking around a city or a remote object without identification marks, you can get a dose of radiation.
Regular dosimeters are issued to employees of the chemical and radiation industry. It's like a piece of equipment - you don't need to buy anything.
What is a dosimeter and how to choose it when you don’t know what and where to look
To choose one or another model of the device, you need to know: what type of radiation you will be in contact with and how often the situation is subject to analysis.
Among all the options, alpha, beta and gamma radiation can be found in everyday life. The most dangerous for all living things is alpha.
It is more difficult to determine it than the others, since the device must be brought close to the source of radiation. The fact is that alpha rays propagate at a distance of 2-3 cm. This requires a Geiger dosimeter with additional sensors.
If you have the necessary funds, then the best option is to purchase a model for measuring three types of radiation at once.
For basic use, a dosimeter-radiometer is enough. It is enough to detect gamma and beta rays. With such a device, you can at least daily measure the room and the environment. It is also not a sin to look at food, vehicles and building materials - they move throughout the country. You never know what will bring from the other end of the region.
The following parameters will help you choose a specific model of dosimetric equipment:
- Tunderlying detector type - the main technical characteristic that affects the degree of measurement efficiency and the accuracy of the result. Between a semiconductor and a gas Geiger detector, it is better to choose the latter.
- INtype of radiation that we are going to measure - devices specialize both in a specific type, and several at once. To measure one type, it is worth constantly switching the operating mode on the multifunctional one. For this, separate buttons or a regulator are provided. A primitive version is a beta radiation detector. The optimal situation is when the dosimeter works in three main directions at once: alpha, gamma and beta.
- Result error – the accuracy of the device directly depends on this parameter. The smaller the error figure, the better and better the device shows in practice. It is normal for a household appliance when the error percentage is about 25-30%. The tool is not suitable for professionals, since almost ideal values \u200b\u200bare needed. An error of 5-7% will be optimal.
- Value range – maximum and minimum positions of the dosimeter that can measure background radiation. Pay attention only to the lower mark - it should not be less than 0.05 μSv / h. The maximum value is enough on any device. Especially for home measurements.
- Device Verification - a special mark from the factory. Indicates that the device gives accurate readings and is manufactured in accordance with all standards, GOSTs, etc. It is desirable that the verification is in the equipment passport. In extreme cases, a QTC (organization of technical control) mark from the manufacturer is sufficient.
Other parameters do not directly affect the operation of the device. These include: weight, appearance, mounts, etc. They help to simplify the measurement, but do not affect the performance of the dosimeter.
