Material for the Calibration of Particle Number Counters

One open issue on the PNC calibration procedure is the selection of the material. The PNCs counting efficiency strongly depends on the properties of the aerosol particles, thus the calibration curve is strictly valid for the test aerosol. It is desirable to find a material with similar behaviour as diesel engine exhaust particles and to qualify uncertainties of the calibration factors between different PNC manufacturers. GRIMM and TSI provided PNCs and AEA, MATTER, GRIMM, TSI provided five particle generators. The experiments were conducted in the European¿s Commissions laboratories (JRC). Heavy duty diesel engine (w/o aftertreatment) particles were also produced (measurements downstream a thermodenuder) at idle and a medium load mode. The measured data were evaluated by JRC. The results showed that the interaction between particles and the PNC working liquid is very important (e.g. C40 particles show high counting efficiency at 23 nm). CAST and emery oil particles give similar efficiencies, close to those measured with engine at medium load. The procedure followed for the measurement of the efficiencies is very important for the limitation of the measurement uncertainties.

GIECHASKIEL Barouch;  CARRIERO Massimo;  KRASENBRINK Alois;  SPIELVOGEL Juergen;  GERHART Christian;  WANG Xiaoliang;  HORN Hans-Georg;  SOUTHGATE Jason;  JING Lianpeng;  KASPER Markus; 

2008-09-15

Hellenic Association for Aerosol Research HAAR

JRC46831