Selection of an individual radiation background dosimeter

A portable or individual dosimeter is used in domestic and industrial environments for continuous or threshold measurement of the level of ion radiation from the environment or background radiation from various objects. Conventionally, there are several main types of devices, each of which has its own narrow purpose.

What is the dosimeter for?

Household portable or individual dosimeters are designed for everyday use, they are ergonomic, characterized by compact dimensions and simple operation. Portable Measuring devices display all the necessary information on the display and do not require additional instruments for decoding data. Customized models are less functional, they are used only to inform about a change in the level of ion radiation in a big way.

Most often, they are acquired to control beta particles or gamma radiation, which are especially dangerous for human health.

Registration of alpha radiation is carried out only with the help of professional equipment. The reason is that alpha radiation causes serious harm only through direct contact with the body, to protect it from fairly simple means, such as closed clothing, respirators.

A portable or individual dosimeter is necessary for people living in adverse areas, where artificial sources of radioactive contamination are located nearby:

• industrial weapons factories;
• NPP;
• medical laboratories or scientific centers where research is conducted (X-ray, radionuclide diagnostics).

In the event of accidents and the spread of dangerous electrons or photons, a person will be informed in a timely manner and will be able to take measures for protection.

It should be noted separately that any household dosimeter is designed to measure the level of ion radiation directly in that placewhere it is located (man, soil, room, surrounding space). He defines dose ratebut hardly able to pinpoint its source.

There are models of household appliances designed to measure the level of contamination of food or various building materials. But they only show critical indicators that exceed the norm several times. For the exact determination of such objects, other methods and devices are necessary, which measure not the radiation power, but the content of radionuclides.

Household dosimeter

Before measuring the ionizing radiation of an object, the dosimeter measures the natural radioactive background.

It should be borne in mind that any output value of the “background” is not constant, as a rule, several measurements are made and the arithmetic average is calculated.

After several registrations, you can proceed to the study of man or soil. Only a constant excess can be interpreted as the detection of radioactive radiation. The user of the dosimeter must not only understand the device interface, but also possess minimal knowledge of the norm. Apparatus for domestic purposes determines two main indicators: dose and dose rate.

Indicator dose rates measured in µSv / h. In simple terms, it denotes the permissible time of stay in the place where the radiation is recorded. The higher the rate, the faster the dose accumulates, therefore, the residence time is reduced.

Dose Measurement - this is a measurement of the background radiation of the area, it is recorded in unfamiliar or remote places of stay. For control, discard the accumulated value in the dosimeter and carry it in a pocket or bag. A safe value does not exceed 0.2 µSv / h, if the device outputs more, it means that being in this place is dangerous to health.

X-ray meter

The main field of application of the dosimeter for monitoring x-ray radiation is medical institutions:

• measuring the level of radiation received by patients under certain procedures;
• monitoring the operation of x-ray equipment;
• reading the absorbed dose at the output of the x-ray apparatus.

In living conditions, X-ray dosimeters measure the background from VCRs, televisions, microwave devices or other sources that propagate X-rays.Unlike portable devices, X-ray not only fix abnormalities, but also control the quantitative characteristic ionizing scintillation, chemical, photographic or other effects of the radioactive background of the object.

Radiometers are divided into two types according to their purpose:

• measuring devices for reading the radiation index directly in the direct beam (with radiation therapy);
• to take readings of the dose rate of scattered radiation under working conditions (at workplaces or indoors).

Individual household dosimeters and kits

An individual dosimeter is a small device for personal wearing in an area with a potentially dangerous radioactive background. Most often, these devices are deprived of the display and more resemble the usual key chain. The principle of operation of such devices is threshold: when the ion gamma radiation exceeds the norm, the dosimeter beeps. These are the most simple and inexpensive household appliances needed when in an unknown, remote area.

A set of individual dosimeters, depending on the model of the device,used to measure the absorbed dose of gamma neutron and X-rays. The device reads the accumulated dose value from any object using special eyepiece. As a rule, such kits do not acquire for domestic use, their field of application is dose measurement in people or objects within potentially dangerous radioactive objects, for example, plants producing medical x-ray devices or weapons.

The kit of individual dosimeters includes several direct reading devices for measuring background radiation, a power supply unit, and a manual.

How to choose a dosimeter

The purchase of such specific and narrow equipment involves the selection of the necessary characteristics. Household dosimeters are relatively inexpensive, but differ in technical indicators. What should I look for when choosing?

1. Type of detecting unit. In home appliances, a common gas-discharge Geiger-Muller counter is most often implemented. Scintillator counters are installed mainly in professional equipment, but they are also found in household devices. Such detection units are more accurate, but more expensive, and have large dimensions.
2. Upper and lower threshold of measured values. Optimal choice in favor of the average range.
3. Time to prepare for work and measurement. If this parameter is critical, it is better to purchase a quick-read model. The time of one measurement cycle of conventional devices from 3 to 60 seconds, and the preparation takes about 4 minutes.
4. Error. When used in harsh weather conditions, a large degree of error will adversely affect the measurement accuracy.
5. Sound signal. The indicator will automatically trigger, informing the user about changes in the radioactive background.

When choosing a suitable model, you should not strive to choose the most versatile option. The purchase of a top position is not always justified; it is necessary for the user to clearly determine for what purpose the device is purchased. Thus, you do not have to overpay for unnecessary features.

Overview of the best household models

There are several main manufacturers of dosimeters whose products have no analogues in the Russian market. The best recommendations were sent to the company. "Quart-rad" which has been developing measuring instruments for radioactive background since the early nineties.The internationally recognized brand of radioactive control equipment “Radex” was created by specialists of the Moscow Engineering Physics Institute (MEPI).

Radex RD1503 +

Classic model personal portable dosimeter with an intuitive control, it is equipped with a Geiger-Muller gas-discharge counter and processes information using embedded program algorithms. The sound signal informs about the registration of each particle and increases with increasing ion radiation.

Main characteristics:

• the time taken to measure a rd1503 + is only 40 seconds;
• spectrum of radioactivity levels up to 9.99 µzv / h;
• registration of gamma radiation from 0.1 MeV;
• registers beta and gamma radiation;
• signal threshold - every 0.10 mkzv / h;
• work without recharging for 550 hours;
• vibration and sound signal;
• error +/- 15%;
• large backlit display.

The device works in conditions of no more than 80% humidity and air temperature from -20 to + 50 °. In RD1503 + it is difficult to find flaws, and user reviews only confirm the excellent quality and compliance with the stated parameters.

Radex RD1008

Design feature RD1008 in stock two gas-discharge meters Geiger-Muller.This solution made it possible to shorten the registration cycle to 10 seconds, which puts the device in the high-speed class. According to manufacturers, the dosimeter measures the level of ion radiation from the environment, as well as the degree of contamination of food. If the device copes with its primary task perfectly well, the measurement of food products will be very approximate.

Model RD1008 is one of the latest developments, the device is able to track the level of accumulated dose for two objects at the same time. Two detectors Beta-2-1 and Beta-2M-1 determine the dose of gamma and beta radiation.

The compact and ergonomic dosimeter works continuously for up to 950 hours, the information is displayed on a wide monochrome display. The RD1008 is equipped with a sound and vibration signal, automatically restarts when abrupt changes in the dose rate of the radioactive background.

The device will cost users more expensive than its analogue RD1530 +, but this is due to its wide functionality. The useful device is easy to use, designed for operation in various conditions.

Radex RD1212-BT

Model RD1212-BT is one of the most miniature and functional. The first thing that attracts attention - built-in module Bluetooth, wireless communication allows you to save measurements on any devices, including GPS-navigator, smartphones based on Android or IOS.

Advantages of RD1212-BT:

• measurement cycle time 10 seconds;
• sound, vibration and visual information (display);
• spectrum of measurements of ion radiation from 0.5 to 999 µzv / h;
• gamma-radiation spectrum from 0.1 to 1.25 meV;
• beta-radiation spectrum from 0.25 to 3.5 MeV;
• X-ray radiation range from 0.03 to 3.0 MeV;
• error +/- 15%;
• 300 hours of uninterrupted work.

Supplements the option of a built-in temperature and atmospheric pressure sensor, clock, flashlight. A modern dosimeter, adapted for all gadgets, quickly and accurately measures the ion radiation of the environment. Comfortable and ergonomic, the RD1212-BT with intuitive controls has a lot of positive feedback from users.