Aerosol Diluter
ISO 14644-3
VDI 3491

DIL 540/C - Self-Adjusting Dilution System for Aerosols


The Self-Adjusting Dilution System DIL 540 is used to defined and reproducible adjustment of the aerosol particle concentration (dilution). It is particularly useful for the verification of the test aerosol for testing cleanroom installations. In the standard EN ISO 14644-3, this is included as a requirement.



  • Dilution ratio is automatically adjusted
  • Mobile use by battery operation
  • Directing the entire intake volume flow of the particle counter from the sampling point via the dilution system (closed system)
  • Constant, reproducible dilution even under changing operating conditions
  • Internal monitoring of the dilution ratio with display
  • Mobile use (no compressed air supply is required, battery operation possible)
  • High durability and reliability, minimum maintenance
  • Over- and under-pressure operation is permitted
  • Adaptation to customer-specific requirements (dilution ratios) possible

For higher dilution ratios the diluters of series DIL can be cascaded easily, or alternatively the High Dilution System HDS 561 can be used.

  • Verification of the test aerosol for testing cleanroom installations
  • Acceptance measurements of laminar flow boxes, safety cabinets and smaller clean rooms
  • Determination of filter separation efficiencies
  • Measurement of highly concentrated aerosols
  • Aerosol research
  • Quick fit tube connector (straight or elbow) (with mounting tool)
  • Other aerosol liquids on request
  • Device carrying case for one dilution system DIL and one aerosol generator series ATM
Koffer DIL_frei


A partial stream is extracted from the raw aerosol flow. The particle concentration in the partial flow (capillary volume flow) will remain unchanged. A HEPA filter is used for separation of particles from the by-pass flow. The two flows are recombined. Dilution results from the ratio of the total flow to the capillary volume flow.
The fluidic design of the device ensures isokinetic sampling at the inlet of the capillary. Interferences of particle size distribution of the aerosol through diluting are therefore minimal.

Optical particle counters have inherently a maximum measurable particle concentration. If this is exceeded, errors are to be expected for reasons of coincidence in the measurement volume of the counter.
By placing the dilution system DIL 540 upstream of the particle counter, the aerosol concentration can be reduced by a factor of 100.

Dilution ratio DIL 540   1:100
DIL 541   1:10
Volume flow rate 28.3 l/min
Filter class HEPA
Hose connectors Ø 8mm (optional 10mm)
Power supply 12 .. 24 V DC, 30 mA (using AC adapter) or
battery 9V cell (6LR61 / PP3)
Dimensions (Wx H x D) 160mm x 300mm x 110mm
Weight 1.5kg

An overview of all device versions of series DIL can be found here: Specifications of the series DIL