Neutron Survey Meter

The NSN3 portable neutron survey meter measures the neutron ambient dose equivalent rate. It is intended for the protection of workers in nuclear facilities and throughout the fuel cycle, research centres, particle accelerators and civil protection first response teams.


NSN3 radiameter: lightweight, reliable and robust to ensure the safety of your technicians and precise measurements

survey meter nsn3 light reliable robust
  • Reduce the time spent on site with easy deployment and handling
  • Optimize your radiation protection measurement campaigns
  • Choose reliability with high-accuracy neutron measurements and data collection
  • Facilitate the recovery of collected data

What is a portable neutron survey meter?

By the ICRP* recommendations, the survey meter for neutron is used for the detection of contamination and the evaluation of the ambient dose equivalent H*(10) before fieldwork, before handling an object and when searching for hot spots. It allows rapid and immediate measurements of neutron radiation.

It is a complementary support to operational dosimetry, which requires personal electronic dosimeters for worker protection and safety.

*ICRP(International Commission on Radiation Protection)

what is a portable neutron survey meter

how the survey meter works

How does the neutron survey meter NSN3 work?

FUJI Electric's neutron survey meter principle major innovation is using an organic gas mixture of methane and nitrogen instead of 3He or BF3.
The elastic diffusion reaction of hydrogen from methane detects fast neutrons. Thermal neutrons, slow neutrons are detected using the 14N (n,p) 14C reaction of nitrogen. The proton energy in this reaction is 626 keV.

By these two reactions, the neutron ambient dose equivalent can be measured from 0.025 eV up to 15 MeV.<br> This unique and patented technology, the result of Fuji Electric's R&D, allows high sensitivity to be achieved with a minimum of moderators in an ultra-light and handy device.


The Portable Neutron meter NSN3 is designed for professionals exposed to radiation

Reduce the time spent on site with easy deployment and handling

reduce your on-site intervention time

The NSN3's portability and low weight of only 3kg make it easy to monitor.

Designed for adaptability in the field, the NSN3 operates on rechargeable or non-rechargeable batteries.

It offers a long battery life of more than 12 hours of continuous display and more than 31 hours of non-displayed time.

It can also be used continuously via a main supply.

Optimise your neutron measurement campaigns

The neutron dose survey meter can be used in portable or stationary mode. Record your data (up to 1200 points) and transfer it to the removable display memory or opt for continuous measurement and unlimited recording via an external power supply with AC adaptor.
Save time and simplify your decontamination procedures with the NSN3's detachable display. Only decontamination of this removable accessory is required before leaving the controlled area.

Choose reliability with high-accuracy neutron measurements and data collection

The high sensitivity of the portable survey meter provides reliable, fast response time, accurate measurements over the energy range from thermal and fast neutrons (0.025 eV to 15 MeV).
It has excellent gamma rejection.

This performance is comparable to that of a transportable device (with a heavy moderator like Ludlum model).

The dose rate measurement range extends from 0.01μSv/hr to 99.99 mSv/hr with an accuracy of ≤ ±20% at 10 μSv/hr.
The dose measurement range extends from 0.01μSv to 99.99 mSv with an accuracy of ≤ ±20% at 1 μSv.

Have confidence in your measurements: the NSN3 survey meter is approved by the Technical Centre for Certification of Radiation Protection Instrumentation CTHIR to IEC610005:2014.

Facilitate the recovery of collected data    

The neutron dose survey meter is equipped with a USB port to display and share collected data on a PC.


Applications and fields of use of the neutron survey meter

applications and fields of use of neutron survey meter

The neutron dose survey meter is designed for:

  • Radiation protection of workers exposed to radiation,
  • The search for neutron sources or the presence of radionuclides,
  • Detection and monitoring of radiological contamination,

It is perfectly adapted to the requirements and applications of:

  • Nuclear power plants,
  • Synchrotrons, particle accelerators,
  • Fusion reactors,
  • Experimental reactors,
  • Particle physics laboratories,
  • Decommissioning activities
  • Spent fuel processing and transport facilities
  • Civil security: protection of first responders
  • Industrial activities and non-destructive testing

Discover the neutron survey meter


The Fuji Electric neutron survey meter ensures rapid contamination detection and efficient monitoring!