Industry Standard for nvPM number instrument

AVL Particle Counter™ Aviation

The AVL Particle Counter (APC) measures the non-volatile particle number concentrations of engine exhaust gas.

AVL Approach

After a primary dilution of the exhaust gas in the APC, the sample is transported to an evaporation tube, where the remaining volatile components are transferred into the gaseous phase. After a secondary dilution, the particles are detected and counted using the light-scattering method.

Benefits at a Glance

  • Patented Primary Diluter shows excellent accuracy and repeatability in terms of dilution
  • Built-in self-diagnostic features (e.g.: system check, response check, zero point check, CPC flow check) to ensure optimal performance
  • Low cleaning and maintenance effort due to the patented design of the primary diluter and the innovative material composition
  • Calibration according to AIR6241 requirements
  • Accurate measurements due to minimization of particle losses and agglomeration
  • Automated start-up procedure and fast warm-up results in high availability
  • Very high sensitivity (dilution rate accuracy = 10%)

Technical Data

Measured value:

Particle number concentration of non- volatile particles (#/cm3)

PNC measuring range (single count mode):

0 to 10,000 #/cm

PNC t10-90 rise time:

≤ 4 sec

Operating temperature:

5°C to 25°C (up to 45°C with optional conditioning trolley)

Max. sample gas temperature:

Max. 200 °C

Differential pressure between measurement channel and ambient air:

+/- 200 mbar

Sample Flow:

5 l/min constant

ET / CS temperature:


Removal efficiency:

99.9% for tetracontane particles


• Ethernet TCP/IP with AK protocol

• RS232 with AK protocol

• Hybrid interface (digital, analog I/O)

Power supply:

90...240 V AC, 50/60Hz, ~1 kVA

Unit dimensions:

482 (19'') x 445 (10HU) x 650 mm

Unit weight:

~ 47 kg (55 lbs)

Compressed air supply:

Acc. to ISO 8573-1, Class 1, Grade E


Measuring Principle

Exhaust gas is sampled and diluted with HEPA filtered compressed air using the AVL Primary Diluter.

Inside the evaporation tube with catalytic stripper the diluted exhaust gas is heated and the volatile emission components are removed, resulting in an exhaust sample which consists of solid particles only.

After that, the exhaust gas is diluted once again using a porous tube diluter and fed into the condensation particle counter (PNC).