Comparison for particle number concentration up to 500'000 cm-3

Project Description

Metric: Aerosol particle number concentration (PNC)
Concentration range: 3 target concentrations in the range 20'000 cm-3 - 500'000 cm-3
Particle size range: 3 target particle sizes in the range 20 nm -200 nm (mobility diameter)
Test aerosol: Polydisperse soot aerosol from combustion generator
Measuring instrument: Condensation Particle Counter (CPC)

The aim of the comparison is to compare the accuracy of National Metrology Institutes‘ when measuring high particle number concentrations in the CPC plateau region.

Progress Report 2021-04-20

The comparison took place at METAS from 3 to 6 February 2020. The participants submitted their results electronically in September 2020. The data analysis showed large deviations between participants. Moreover, two participants had not fully calibrated their measurement devices according to traceable national standards but relied on calibration certificates by instrument manufacturers. Two more participants had to partially withdraw their results due to data handling errors. As a result, the reference value suffers from large uncertainties.

The Consortium proposes to repeat the inter-comparison at PTB in spring 2022 under the same registration number (1480). METAS will hand over coordination of the Pilot Project 1480 to PTB.

Progress Report 2020-02-26

The comparison took place at METAS from 3 to 6 February 2020. The participants are expected to submit the results electronically by 15 May 2020.

Metrology in Chemistry (MC)
Coordinating Institute
METAS (Switzerland)
Further Partners
AIST (Japan)