MODEL 5523-Ni


Bipolar neutralizer for β radiation

The GRIMM 5523-Ni aerosol neutralizer is based on the radioactive decay of Ni-63, that produces a bipolar ionic atmosphere by β- radiation. Irregularly charged particles (from ambient or lab generated) are brought into a defined stationary-state charge distribution, regardless of their initial charging state. Aerosol neutralizers based on radioactive sources are nearly maintenance free and well proven. The use and transport are however subject to legal restrictions and requires tedious bureaucracy. These efforts can be avoided by using the isotope Ni-63 with its extraordinary high radionuclide specific exemption limit of 100 MBq as it is a low energy beta emitter with low biological hazardousness. Therefore, no handling license is required1) for the GRIMM 5523-Ni with its nominal activity of 95MBq. In instrument inter-comparisons, the GRIMM 5523-Ni features good comparability with Kr-85 reference neutralizers.


NOTE: The regulations concerning radiation protection (for X-ray radiation) differ between the countries and the individual federal states. To obtain information on the handling regulations, please contact the competent authority in your country / federal state.


  • Ni-63 β- radioactive source
  • nominal activity 95 MBq
  • aerosol flow rate up to 1 L/min
  • no handling license required1) as activity below 100 MBq
  • low maintenance
  • easy to operate and safe
  • ompatible with GRIMM SMPS+C and SMPS+E systems
  • hazardous goods transportation according to UN 2910; no special measured needed


1) one exemplar only allowed. Check local radiation protection directive.


  • neutralizer for aerosol sizing with SMPS systems
  • neutralizer for particle generators
  • fundamental aerosol research
  • investigation of particle charging


source type

Ni-63; unsealed radioactive source; cleaning not permitted

ion generation method

beta (β-) radiation, maximum energy 66 keV, no photons

nominal activity

95 MBq (+0 / -10%)


96 y


aerosol flow rate

up to 1 L/min

aerosol medium

Air or N2


stainless steel with additional lead sheath

dimensions (h x w x d)

18 x 6.9 x 6.9 cm (7.1 X 2.7 x 2.7 inch)


2.5 kg (5.5 lbs


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