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LAP 340

Optical Particle Counter LAP 340 for analysis of particle size distributions and particle concentrations in aerosols, best for cleanroom applications

The Cleanroom Particle Counter LAP 340 is a device for measuring the number and size of particles in air streams and gaseous media according to ISO 21501-4.
Laser Aerosol Particle Counter LAP 340, front view Laser Aerosol Particle Counter LAP 340 Display
The measuring system is suitable for stationary as well as mobile use.

The particle analyzer is especially suitable for clean room applications which enables it to cover a wide particle size range from 0,3 µm to 10 µm and a maximum measurable particle number concentration of 980'000 #/ft³ (35 #/cm³), in the standard version. That opens a wide range of measuring tasks.

These include monitoring and checking of clean rooms, clean benches, filter facilities in operation rooms, filling facilities in the pharmaceutical industry and separation efficiency tests of filters.


ISO 21501-4
ISO 14644-3
VDI 2083
DIN 1946-4
DIN 12980
DIN EN 12469
SWKI 99-3
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  • quick instrument setup
  • portable particle counter for stationary as well as mobile use
  • automatic calibrating function enables an easy checking and recalibration of the system
  • connection possibilities for climate sensors (air humidity, temperature, differential pressure, flow velocity)
  • user-friendly software for measuring and archiving


  • clean room qualification and clean room validation measurements
  • monitoring of clean rooms and laminar air flow boxes
  • emission characterisation (e. g. vacuum cleaner testing)
  • fractional efficiency tests of filters and separators
Parameter title Unit Value
test flow rate L/min 28,3
measurand(s) - particle number, particle size distribution
measuring range, particle size µm 0,3 ... 10
resolution, measurement time s min. 1 (adjustable)
power supply - 230/115 V AC, 50/60 Hz, max. approx. 250 W
others - thermal printer
communication interface - RS 232 C
dimensions (w × h × d) mm 430 × 270 × 280
weight kg approx. 10
  • Pirker L, Čebašek M, Serdinšek M, Remškar M Size- and time-dependent aerosol removal from a protective box during simulated intubation and extubation procedures COVID 1 (2021) 1, 315-324
  • Saeedi A, Sargolzaei J Fractional efficiency of porous media used for natural gas filtration Journal of Natural Gas Science and Engineering 96 (2021) 104247,
  • Schuldt T., Däuber E., Engelke T. and Schmidt F. Air filters for indoor environments: Interlaboratory evaluation of the new international filter testing standard ISO 16890. Indoor Air 30 (2020) 3, 464-480

Silimar products

LAP 340/L

Optical Particle Counter LAP 340/L for analysis of particle size distributions and particle concentrations in aerosols, best for filter testing (2,83 L/min)

Laser Aerosol Particle Counter LAP 340, front view
detail view