Continuous Particle Number Concentration Determination of Ambient Air in Measurement Networks
Markus Pesch, Friedhelm Schneider, Torsten Bayer, Michael Schüler, Katharina Roloff, GERHARD STEINER,
Grimm Aerosol Technik Ainring Abstract Number: 602
Working Group: Urban Aerosols
AbstractRecently WHO published new Global Air Quality Guidelines (WHO, 2021), once more stressing the danger of air pollution on human health, and addressing this, for the first time, also to the number of ultrafine particles (UFP, particles < 0.1µm) in the ambient air. No definitive air quality guidelines are expressed for UFP yet, however, WHO highlights best practices and the importance of the continuous measurement of ultrafine particles.
Furthermore, the European CEN/TS 16976:2016 guideline expands the need to measure ultrafine particles in the ambient air also to address the impact of UFP on the global climate. This guideline also underlines the need to determine the particle number (PN) of the ambient aerosol to supplement commonly applied measurement procedures of determining particulate mass fractions such as PM10 or PM2.5, as mass is not a feasible metric for ultrafine aerosols.
This CEN/TS aims to harmonize currently available measurement techniques for the determination of the particle number concentration in the ambient air, thereby defining instrument performance characteristics such as overall instrument counting efficiency, D50/D90 diameters and specifying the range of measurement uncertainties in instrument calibrations.
Here, we are reporting preliminary results of two 1-month measurement campaigns in Halle (Saale), Germany and Berlin, Germany, carried out in collaboration with the authorities operating the local air quality monitoring networks. In both measurement campaigns, instruments were deployed at existing measurement stations close to heavily frequented streets and at rather remote background locations and operated with high temporal resolution.
For the determination of the particle number of ultrafine aerosols, we were using the GRIMM condensation particle counters EDM 465 and CPC 5421, specifically designed for 24/7 use and mounted in dedicated weatherproof and climate controlled outdoor shelters. Both instrument models were calibrated in accordance to CEN/TS 16976:2016 and were using sample collecting probes with integrated membrane dryers. In addition to the UFP measurements, PM10 and PM2.5 values were determined with GRIMM EDM 180 optical aerosol spectrometers.
We will give details on the used measurement instruments, describe the measurement sites, and will give an outlook on possible data analysis using GRIMM aerosol monitors for long term measurements.
Acknowledgement:
We would like to thank the Senate Department for the Environment, Urban Mobility, Consumer Protection and Climate Action of the City of Berlin for their collaboration and the access to their measurement sites within the Berlin air quality network BLUME.