Portable or individual dosimeter is used in domestic and industrial conditions for continuous or threshold measurement of the level of ionic radiation of the environment or radiation background from various objects. There are several main types of devices, each of which has its own narrow purpose.
What do you need a dosimeter for?
Household portable or individual dosimeters are designed for everyday use, they are ergonomic, differ in compact dimensions and simple management. Portable measuring devices display all the necessary information and do not require additional devices to decrypt the data. Individual models are less functional, they are used only to inform about the change in the level of ionic radiation in the greater direction.
Most often they are bought to control beta particles or gamma radiation, particularly dangerous to human health.
Registration of alpha radiation is carried out only with the help of professional equipment. The reason is, that alpha radiation causes serious damage only when directly ingested, for protection against it simple enough means, such as indoor clothing, respirators.
A portable or individual dosimeter is needed for humans, living in disadvantaged areas, where artificial sources of radioactive contamination are located nearby:
- industrial factories for the production of weapons;
- AES;
- medical laboratories or research centers, where research is conducted (X-ray diagnostics, radionuclide diagnostics).
In the event of accidents and the spread of dangerous electrons or photons, people will be informed in a timely manner and will be able to take measures to protect.
It is worth noting that fact, that any household dosimeter is designed to measure the level of ionic radiation directly in that place, where it is located (man, priming, room, surrounding space). It determines the dose rate, but is 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 reflect only critical indicators, exceeding the norm several times. Other methods and devices are needed to accurately identify such items, not the radiated power is measured, and the content of radionuclides.
household dosimeter
Before measuring the ionizing radiation of an object, the dosage measures the natural radioactive background.
It should be borne in mind, that any output value "background" is not constant, usually, make several measurements and calculate the arithmetic mean.
After several registrations, you can begin to study the person or the soil. Only a constant excess can be interpreted as the detection of radioactive radiation. The user of the dosimeter must not only understand the interface of the device, but also to have a minimum knowledge of the norm. The household appliance determines two main indicators: dose and dose rate.
The dose rate is measured up to μSv / year. Simply put, it indicates the allowable time spent in place, where the radiation is recorded. The higher the figure, the faster the dose accumulates, so, reduced residence time.
Dose measurement is a measurement of the background radiation of an area, it is registered in unfamiliar or remote places. To control, reset the accumulated value in the dosimeter and carry it in your pocket or bag. The safe value does not exceed 0,2 μSv / year, if the appliance outputs more, means, being in this place is dangerous to health.
X-ray meter
The main area of application of the dosimeter for X-ray control is medical institutions:
- radiation level measurement, obtained by patients under certain procedures;
- control of X-ray equipment;
- reading the absorbed dose at the output of the X-ray machine.
In domestic conditions, X-ray dosimeters measure the background of VCRs, TVs, Microwave devices or other sources, propagating X-rays. Unlike portable devices, X-rays not only record abnormalities, but also control the quantitative characteristics of ionizing scintillation, chemical, photographic or other effects of the radioactive background of the object.
Radiometers are divided into two types by purpose:
- measuring devices for reading the indicator of radioactive radiation directly in the direct beam (during radiation therapy);
- to take readings of the power of scattered radiation doses under operating conditions (in the workplace or indoors).
Individual household dosimeters and kits
Individual dosimeter is a small device for personal wearing in an area with a potentially hazardous radioactive background. Most often, these devices are devoid of display and more like a normal keychain. The principle of operation of such devices is threshold: when the ionic gamma radiation exceeds the norm, the dosimeter beeps. These simplest and inexpensive household appliances are necessary when staying in the unknown, remote area.
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 value of the accumulated dose from any object using a special eyepiece. Usually, such kits are not bought for household use, their scope is the measurement of the dose to humans or objects within potentially hazardous radioactive objects, example, factories for the production of medical X-ray devices or weapons.
The set of individual dosimeters includes several direct-point devices for measuring the radiation background, Power Supply, leadership.
How to choose a dosimeter
The purchase of such specific and narrow-profile equipment implies the choice of the necessary characteristics. Household dosimeters are relatively inexpensive, but differ in technical parameters. What to look for when choosing?
- Detection unit type. The usual Geiger-Mueller gas discharge meter is most often implemented in household appliances.. Scintillation counters are installed mainly in professional equipment, but are also found in household, such detection units are more accurate, but more expensive, have larger dimensions.
- Upper and lower threshold of measured values. It is optimal to make a choice in favor of the average range.
- Preparation time and measurement. If this parameter is critical, it is better to buy a fast-reading model. The time of one cycle of measuring conventional instruments from 3 to 60 seconds, and the preparation is close 4 minutes.
- Error. When used in harsh weather conditions, a large degree of error will adversely affect the measurement accuracy.
- Sound signal. The indicator will work automatically, informing the user about the change of radioactive background.
When choosing the right model, do not try to choose the most versatile option. Buying a top position is not always justified, the user needs to clearly define, for what purposes this device is purchased. So, do not have to overpay for unnecessary opportunities.
Review of the best household models
There are several major manufacturers of dosimeters, whose products have no analogues in the Russian market. The best recommendations are sent to the address of the company "Quarta-radium", which has been developing radioactive background measuring instruments since the early 1990s. World-renowned brand of radioactive control equipment "Radex" created by specialists of the Moscow Institute of Engineering Physics (MYTHS).
Radex RD1503 +
The classic model of the individual portable dosimeter with intuitive control is equipped with the Geiger-Mueller gas-discharge counter and processes the information by algorithms of the built-in program. The sound signal informs about registration of each particle and amplifies at increase of ionic radiation.
Main characteristics:
- time, spent on measurements, in rd1503 + is all 40 seconds;
- spectrum level of radioactive background to 9,99 μSv / year;
- registration of gamma radiation from 0,1 MeV;
- registers beta and gamma radiation;
- signal threshold - each 0,10 μSv / year;
- work without recharging for 550 h;
- vibration and sound signal;
- error +/- 15%;
- large backlit display.
The device works in conditions no more 80% humidity and air temperature from -20 to + 50 °. In RD1503 + difficult to find flaws, and user feedback only confirms the excellent quality and compliance with the stated parameters.
Radex RD1008
Design feature of RD1008 in the presence of two gas-discharge Geiger-Mueller counters. This decision allowed to reduce the registration cycle to 10 seconds, which allows you to set the speed class. According to the manufacturers, the dosimeter measures the level of ionic radiation of the environment, as well as the degree of contamination of food. If the device copes with its main task perfectly, then food measurements will be very approximate.
Model RD1008 is one of the latest developments, the device is able to monitor the level of accumulated dose on the objects at the same time. Two detectors Beta-2-1 and Beta-2M-1 determine the dose of gamma and beta radiation.
Compact and ergonomic dosimeter works continuously 950 hours, the information is displayed on a wide monochrome display. RD1008 is equipped with a sound and vibration signal, automatically reboots at sharp changes of dose rate of a radioactive background.
The device will cost users more than its counterpart RD1530 +, but this is due to its broad functionality. Useful device is easy to use, designed for operation in different conditions.
Radex RD1212-ВТ
Model RD1212-BT is one of the most miniature and functional. First, what attracts attention is the built-in Bluetooth module, wireless communication allows you to store measurement readings on any device, including GPS navigator, smartphones based on Android or iOS.
Advantages of RD1212-BT:
- measurement cycle time 10 seconds;
- sounds, vibration and visual information (output on the display);
- spectrum of ionic radiation measurements from 0,5 to 999 μSv / year;
- spectrum of gamma radiation from 0,1 to 1,25 MeV;
- spectrum of beta radiation from 0,25 to 3,5 MeV;
- range of x-rays from 0,03 to 3,0 MeV;
- error +/- 15%;
- continuous operation time 300 hours.
The option is complemented by a built-in temperature and atmospheric pressure sensor, watch, flashlight. Modern dosimeter, adapted to all gadgets, quickly and accurately measures ionic environmental radiation. Comfortable and ergonomic, RD1212-BT with intuitive controls has many positive reviews from users.