"Rhythm -1M"
The gamma-radiation survey dosimeter “Rhythm -1M”
Dosimeter “Rhythm -1M” has successfully passed the State acceptance tests and entered into register No Y 1546-01 of measuring equipment admitted for use in Ukraine.

   The instrument has a wide range of advantages:

•  The combination in one instrument of survey and dosimetric functions;
•  High sensitivity and the ability to measure small values of power of equivalent dose - "Rhythtm-1M" is the first in Ukraine instrument certified in range of 0.01 µSv/hr (1µR/hr);
•  The possibility of quick measurements and quick survey - setting time and time of response to the anomaly makes up 0.5 seconds;
•  Accurate measurements and detection of small anomalies with time of filter 50 second;
•  Audible signalling with a pitch of tone depending on the radiation power - in all ranges of instrument operation;
•  Using a miniature headset in noisy environments;
•  High contrast and considerable size of backlit display (digit height - 12.7 mm);
•  Battery power with a quick charger;
•  Small weight and dimensions;

   The dosimeter is used:

•  In liquidation of radiation accidents;
•  For goods and vehicles control at the state border;
•  For radiation control of construction objects, scrap metal and other products;
•  For organization of the continuous monitoring of the radiation situation at the checkpoints and in systems of radiation safety of especially important objects;
•  For pedestrian and automobile gamma survey in geological mapping;
•  For dosimetric environmental monitoring;
•  In radiation control services of administrations of environmental control, scientific, industrial and other institutions and organizations;
•  At the enterprises of sphere of radioactive waste management and nuclear power engineering;
•  For radiation control in case of carrying out of activities in sphere of using nuclear energy.

   Operational experience of these instruments has shown high efficiency of survey mode , speed and accuracy of dosimetry mode. With the help of instrument "Rhythm 1" there are detected radiation dirty pieces of scrap, radioactive spots, lost sources of ionizing radiation and other radiation-hazardous materials.

   The delivery set of instrument includes the following: a measuring unit with digital display and backlight, the detection unit with a protective cover, grip detector, headset, Ni-MH rechargeable batteries, unit of power supply and battery charger, a bag for measuring unit, container, set of operational documentation.

Short technical characteristics of the device:

Measurement range of power of equivalent dose of gamma radiation

From 0.01 to 19,990 µSv/ h

Operational range of energy of gamma-radiation

0,05 ... 3 MeV

The limits of permissible major relative error


Energy dependence


Time for setting up operational mode

1 second

Switchable time for setting up readings of measurement

0,5; 1; 2; 10; 50 second

Material of Detector

NaI Ø40x40

Version of detector unit


Sensitivity - not less than

800 c-1/µSv/h (Cs137)

The dosimeter is sensitive to neutron radiation


Audible alarm - threshold, with variable frequency, adjusted volume and
with digital display of  threshold setting

Time of continuous battery life
 There is provided automatic disconnection of supply ,
when battery is discharged

20 hours

The dosimeter is resistant to vibrations and shocks with a peak acceleration of 150 m/s2

Operating temperature range

-20 ... + 50 °C

Mass of working set

1,7 kg

Overall dimensions of measuring unit


Overall dimensions of detector unit


   Using the new device for control of radiation purity of goods enables to improve significantly production capacity due to high sensitivity and speed of measurement. For the rapid detection of radiation contamination, you can perform control "on- the -fly" with measurement time of 0.5 seconds. You can estimate the radiological purity of food and construction materials for a measurement time of 50 seconds. In new instrument is implemented convenient and efficient searching mode with accompanying sound. The pitch of the sound increases with the dose rate and the search may be conducted without looking at the display and without losing land navigation. In noisy environments there is used miniature headset, which can be worn under a cap (in cold weather or for covert surveillance). At night, LED backlit of a digital liquid crystal display is used. LCD is sufficiently contrast and easy to read in any light and temperature.

Survey dosimeter of gamma-radiation "Rhythm-1M" with respect to functionality and technical characteristics is fully consistent with the recommendations of the IAEA " Detection of radioactive materials at borders" TECDOC-1312

Our adress:

03680, Ukraine, Kyiv, Palladina Avenue, 34a.
E-mail: mpopyt@yandex.ru
Web: https://нпп-опыт.рф
Skype: opyt.narod
Director: Mr Igor A. Makhnyov
 © 2023 SPSJE "OPYT".