A highly-sensitive and compact device intended to detect, localize and identify radioactive and nuclear materials by their gamma and neutron radiation as well as the amplitude gamma spectra. SPECTRA identifies radionuclides with indication of the category that they belong to (in compliance with the IAEA requirements).  It is used to prevent illicit transfer of these materials across the state borders, as well as at the companies and institutions dealing with gamma and neutron radiation sources.

A brand new search algorithm provides high sensitivity of the device and its instant actuation at the slightest change of gamma or neutron background level. New generation scintillation detectors with the silicon photomultiplier ensure high thermal stability of the device and entirely eliminate the “microphone effect”.

The device offers an outstanding user experience due to its innovative design, compact size, large colour display and a 200 hours continuous operation time.

Search Dosimeter-Radiometer MKS-11GN

  • Highly-sensitive and compact SPRD
  • Complies with the ANSI 42.48 & ANSI 42.32, ANSI 42.33
  • State Sanitary-Epidemiological Conclusion # 05.03.02-04/66343 as of June 21, 2011
  • ТУ У 33.2-22362867-021:2011
  • Available in two colours: yellow and olive green (NATO green)

Purpose of Use

  • Identification of the radionuclides type by their amplitude gamma spectra.
  • Determination of gamma and neutron radiation intensity.
  • Measurement of ambient dose equivalent rate of gamma and X-ray radiation (photon ionizing radiation DER).
  • Indication of ambient dose equivalent rate of neutron radiation (neutron ionizing radiation DER).
  • Measurement of gamma and X-ray radiation ambient dose equivalent (DE)
  • Saving amplitude gamma spectra and events logs in the nonvolatile memory.


  • New generation high sensitivity CsI scintillation detectors of gamma and LiI of neutron radiation with solid state (silicon) photomultiplier.
  • Color display with high resolution.
  • Storage and transfer of 250 complete gamma radiation spectra.
  • Powerful CPU and improved algorithms for spectra processing.
  • New software for detailed laboratory research and spectra processing.
  • Integrated GPS/GLONASS-receiver.
  • No “microphone effect”.
  • High thermal stability.
  • Powered by built-in lithium polymer storage batteries that can be charged via USB-cable.
  • The dosimeter communicates with a PC via USB-port.
  • Real-time identification of spectra.
  • Identification of radionuclides with specification of the categories they belong to (in compliance with IAEA requirements):
    – medical radionuclides: 18F, 67Ga, 51Cr, 75Se, 89Sr, 99Mo, 99mTc, 103Pd, 111In, 123I, 125I, 131I, 153Sm, 201Tl, 133Хе;– industrial radionuclides: 57Co, 60Co, 133Ba, 137Cs, 192Ir,152Eu, 22Na, 241Am;
    – special nuclear materials: 233U, 235U, 237Np, Pu [Reactor grade plutonium (more than 6% 240Pu)];
    – naturally occurring radioactive materials: 40K, 138La, 226Ra, 232Th-decay series, 238U-decay series.

    Note. The list of nuclides the device is able to identify may be extended if needed.

  • Threshold alarm system with four independent threshold levels:
    – search threshold level (threshold level of count rate from the detector photon and neutron ionizing radiation);
    – safety threshold level (threshold level of photon ionizing radiation DER);
    – accumulated dose threshold level.
  • Light color alarm (indication) of threshold levels exceeding (gamma radiation – red color, neutron – blue) and visual alarm on the side of the device.
  • Ingress protection rating IP67.
  • Sample of Th232 (Thorium) is included into the Delivery kit for detector age compensation.


Gamma radiation sensitivity for 137Cs, not less thancps/(µSv/h)400
Neutron radiation sensitivity for:  
– thermal neutrons, not less thanpulse·cm2/neutron1.2 ± 0.12
– fast neutrons, not less thanpulse·cm2/neutron0.120 ± 0.012
Measurement range of photon-ionizing radiation DER0.01 µSv/h … 1 Sv/h
Indication range of neutron radiation DER0.01 µSv/h … 10 mSv/h
Measurement range for Gamma and X-ray radiation ambient dose equivalent0.1 µSv … 9,999 Sv
Indication range of photon-ionizing radiation count ratecps1 … 25000
Indication range of neutron radiation count ratecps0.01 … 25000
Main relative permissible error limits of photon-ionizing radiation DER measurement with confidence probability of 0.95 (137Cs)%±(15+1/H*(10)), where H*(10) is a numeric value of measured DER equivalent to μSv/h
Energy range of registered photon-ionizing radiationMeV0.02 … 3.00
Energy dependence of the device readings during photon-ionizing radiation DER measurement in the energy range from 0.05 to 3.00 MeV relative to 0.662 MeV energy (137Cs)%±25
Energy range of registered neutron radiationfrom 2,5·10-8 to 14 MeV
Number of amplitude gamma spectrum channelschannel2048
Energy resolution for 137Cs, not more than%8
Setup time of operating mode of the device, not more thanmin1
Calibration time relative to gamma backgrounds2 … 60
Response time for photon-ionizing radiation DER variation greater than 10 timess0.25
Operating supply voltage of the dosimeter from Li-Ion  storage batteryV3,7
Time of continuous operation with fully charged storage batteries under conditions of normal background radiation with switched off display backlight, not lesshours200
Operating temperature range°С-20 … +50
Dimensions of the dosimeter without a clip, not more thanmm67 х 127 х 30
Dimensions of the dosimeter with a clip, not more thanmm67 х 127 х 45
Weight of the dosimeter, not more thankg0.28