Neutron Survey Meter

Radiation meters are essential measuring instruments. They are used for rapid contamination detection and neutron radiation monitoring. These devices are used in a number of contexts: before an intervention in the field, when handling objects in a specific space, and for locating hot spots.

Discover the neutron survey meter


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?

In accordance with ICRP* recommendations, radiation meters have several uses:

  • Neutron dose rate probes are used to detect contamination.
  • These neutron counters enable the equivalent dose rate to be monitored and measured.
  • These neutron dosimeters are useful for measuring H*(10) ambient integrated dose equivalents.
  • These neutron probes enable fast, immediate measurements of neutron radiation.


These instruments for neutron monitoring are essential before any intervention in the field, before handling objects in specific spaces, and when searching for hot spots.

This neutron dose rate probe complements 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?

The major innovation in FUJI Electric neutron probes is the use of an organic gas mixture of methane and nitrogen instead of 3He or BF3.
Fast neutrons are detected by the elastic diffusion reaction of hydrogen from methane.
Slow, thermal neutrons are detected using the 14N (n,p) 14C reaction of nitrogen. The proton energy in this reaction is 626 keV.

With these two reactions, measurement of the ambient neutron dose equivalent can be obtained from 0.025 eV up to 15 MeV.
This unique, patented technology, the fruit of Fuji Electric R&D, enables high sensitivity to be achieved with a minimum of moderator, in an ultra-light, easy-to-handle neutron detector.


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

To optimize safety and efficiency when working in a nuclear environment, the use of suitable equipment is essential. Thanks to its portability and low weight of just 3 kg, the NSN3 field radiameter is the ideal choice, greatly facilitating monitoring and radiation protection operations. Whether inside the reactor building during scheduled maintenance, or on irradiated fuel transport containers before they leave for reprocessing plants, this instrument is indispensable.

The NSN3 neutron detector is distinguished by its design, which favors adaptability in the field. It is compatible with both rechargeable and non-rechargeable batteries. This feature gives the equipment long autonomy: over 12 hours with the display activated. Without the display, its operating time extends to over 31 hours, and it can be plugged into the mains for continuous radiation monitoring.

With its modular display, the device offers the option of retrieving data while leaving the unit in place, making the control site easily accessible. This feature ensures that the operator remains in a safe zone while taking essential measurements via a remote control system. In line with the ALARA (As Low As Reasonably Achievable) principle, the NSN3 neutron survey meter ensures maximum protection for personnel, while guaranteeing the reliability and accuracy of measured information.

Optimize your neutron counting and measurement campaigns for radiation protection

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-precision neutron dose rate 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.

These performances are comparable to those of a transportable neutron detection device (with heavy moderator).

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 rate probe is equipped with a USB drive for displaying and sharing 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 radiameter 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,

Neutron probes are ideally suited to the requirements and applications of :

  • Nuclear reactors, fuel chain and dismantling operations, fusion reactors and prototypes
  • Research institutes, particle laboratories, synchrotrons, particle gas pedals and educational institutions
  • Hospitals, radiology departments, radiation treatment centers and medical device production units, nuclear medicine: radiotherapy
  • Radiation protection departments, universities and colleges
  • Military defense and civil security: support and protection for first responders, departmental fire and rescue services (SDIS): mobile radiological intervention units (CMIR)
  • NRBC (Nuclear, Radiological, Biological and Chemical), Defense Equipment Agency, Ministry of the Armed Forces, Rapid Intervention Forces (FAR)
  • Industrial sites (oil and gas) and industrial activities: non-destructive inspections and radiography
  • Radioactive waste management, treatment facilities and transport of irradiated materials
  • Airports and customs (radiological inspections)
  • Pharmaceutical and biotechnology laboratories
  • Space missions: radiation monitoring for astronauts
  • Teaching and training: practical demonstrations in physics classes
  • Uranium mines: monitoring worker exposure
  • Radiation sterilization centers for medical and food products
  • Detection of radioactive sources for public safety purposes
  • Radioactively contaminated historic sites for environmental assessments
  • Metallurgical industry: radiation control in recycling processes


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