Real-time particle size distribution and total concentration measurement

ELPI+™ is a new, improved version of the widely used and well characterized ELPI™. ELPI+™ enables measurement of real-time particle size distribution and concentration in the size range of 6 nm – 10 µm with 10Hz sampling rate. The ELPI+™ features include real-time stand-alone operation, wide particle size range and robust structure for operation even in harsh conditions. The use of impactor technology enables post-measurement chemical analysis of size classified particles. In addition, the ELPI+™ can be used for real-time particle charge distribution and gravimetric impactor measurements. All these features enable the use of the ELPI+™ instrument in a wide range of particle measurement applications.


The ELPI+™ operating principle can be divided into three major parts: particle charging, size classification in a cascade impactor and electrical detection with sensitive electrometers. The particles are first charged into a known charge level in the corona charger. After charging, the particles enter a cascade low pressure impactor with 14 electrically insulated collection stages. ELPI+_Messprinzip

The particles are collected in the different impactor stages according to their aerodynamic diameter, and the electric charge carried by particles into each impactor stage is measured in real time by sensitive electrometers.
This measured current signal is directly proportional to particle number concentration and size. The particle collection into each impactor stage is dependent on the aerodynamic size of the particles.
Measured current signals are converted to particle size distribution using particle size dependent relations describing the properties of the charger and the impactor stages.

The result is particle number concentration and size distribution in real-time. By switching the charger unit off, the ELPI+™ can be used for particle charge distribution measurements.



Special Features:

  • Wide particle size range; 6 nm – 10 µm
  • 14 size fractions
  • Possibility for chemical characterization of size classified samples
  • Wide operational concentration range
  • Automated charge distribution measurements
  • Automatic flow control and pressure adjustment
  • Independent stand-alone operation or control via notebook using ELPI+VI software
  • Large 7” display with graphic user interface
  • 6 analog inputs, 3 outputs, all 0 – 10V

ELPI+™ Benefits:

  • Improved sensitivity
  • 10Hz sampling rate
  • Optimized charger operation
  • Improved impactor design with more size resolution
  • Optimized calculation procedures
  • Simplified user interface
  • Stand-alone operation
  • Wide particle size and concentration range
  • Sophisticated calibration of each instrument
  • Robust structure

ELPI+™ Applications:

  • Combustion studies
  • Outdoor and indoor air
  • Automotive exhaust measurements
  • Blow-by gas measurements
  • Pharmaceutical inhaler studies
  • Particle charge distribution measurements
  • Filter grade efficiency studies
  • Nanoparticle measurement

ELPI+™ Accessories:

  • Aluminium and polycarbonate impactor collection foils, 25mm
  • Collection substrate spray (DS-515) with a stencil (DS-125)
  • Vacuum pumps
  • Spare impactors and collection plate sets
  • Dekati® Dilution Systems for conditioning sample from combustion flue gas and automotive exhaust
  • Dekati® Dryer (DD-600) for removing water from ambient aerosol
  • Sample inlets for air quality measurements

Particle size range:
0.006 – 10 µm

Number of size classes:

Sample flow rate:
10 lpm

ELPI+™ dimensions:
400 mm H x 420 mm W x 220 mm D

Collection plate diameter:

Unit weight:
15 kg without impactor; 22 kg with impactor in its place

16 m³/h @ 40 mbar

Operating Temperature:
10 – 35° C

Operating humidity:
0 – 90% RH, non-condensing

Sampling rate:

100 – 250 V, 50 – 60 Hz, 200 W

Computer requirements:

MS-Windows XP™, Vista™, 7™

Connection to PC:
RS-232 or Ethernet,
6 analog inputs, 3 outputs, 0 – 10 V


Manual ???

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