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ATM 226 – Clean Room Aerosol Generator

The Atomizer Aerosol Generator ATM 226 is especially suited for clean room and filter testing applications according to international standards.

Function test at laminar flow boxes (DIN EN 12469) and cytostatica safety workbenches (DIN 12980), the qualitative test of filters for suspended matter (HEPA and ULPA filters),  and acceptance measurements in clean rooms (according to DIN ISO 14644 and VDI 2083) are a essential necessity for personal security and product safety.

Such measurements and checkouts need a suitable test aerosol. Therefore VDI-directive 3491 proposes an aerosol generator for producing a test aerosol with defined characteristics, like the ATM 226. By high generated particle numbers at a particle size distribution orientated at the Most Penetration Particle Size (MPPS) of the filter the locating of leaks in the system is possible fast and safe. If an oily aerosol substance is used (e.g. DOP, DEHS) the aerosol generator produces spherical particles mainly in the size range 0.1…0.5µm with a calculable residence time. That does nearly not extra contaminate the filter material. A further range of application for aerosol generators / liquid aerosol nebulizers is calibration of measuring devices and visualization of currents. That enables measurements of local velocities and flow profiles of the tracer particles by means of optical methods.


The newly developed atomizer is the key part of the ATM 226 (registered design announcement GS 9408604.4). It is made of high quality stainless steel and works as a two-stream nozzle, based on the injection principle. The unique feature is that the outlet points towards the wall of the glass vessel which works as the baffle plate. This particle impaction section removes coarse spray droplets and results in a particle size distribution mainly below 1µm. With increasing flow rates the cut point of the impactor is improved, but in the submicrometer range that has only slight influence on the particle size distribution of the aerosol.

A low-noise compressor produces the compressed air required for generating the aerosol. The air is cleaned by a HEPA-filter before it is introduced to the atomizer.


  • Compact stainless steel housing – suitable for clean room application
  • Connection directly to mains supply
  • Polydisperse aerosol, mainly <1 µm
  • Very high permanence of the generated particle size distribution
  • Defined and high particle number concentration
  • Easy handling, designed for mobile use (internal pump)
  • Testing of HEPA and ULPA filter media
  • Acceptance measurements of clean rooms and  safety cabinets
  • Generation of tracer particles at low flow rates
ATM 226 - Clean Room Aerosol Generator
Power supply100…240 V AC
Volume flowmax. 300 l/h
Mass flow aerosol fluidmax. 300 l/h
Operating timemax. 25 h
Counter pressuremax. 20 kPa (2.9 psi)
Aerosol putletdiam. 8 mm
Weight4.8 kg
Dimensions300 mm x 120 mm x 195 mm
Particle materialsDEHS, PAO (Emery 3004), paraffin oil, saline solution, Latex-suspensions

Aerosol Specification for DEHS
Number concentration>108 Particles/cm³
Number concentration (0.2 µm)2×107 Particles/cm³
Number concentration (0.5 µm)5×105 Particles/cm³
Number concentration (1 µm)1×105 Particles/cm³
Number concentration (0.3 to 0.5 µm)1.5×107 Particles/cm³
Number concentration ( 0.5 to 1.0 µm)8×106 Particles/cm³
Median value0.1 .. 0.5 µm

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User Manual