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Air quality and aerosol metrology

Novel nanoparticle generation sources and instrument characterisation

Development of new novel generation sources for toxicology studies and instrument calibration 

Our research into novel nanoparticle generation sources has resulted in the development of new techniques to drive health-related, toxicology studies.  

We use soot generators and a silver particle generation facility to produce accurately characterised aerosols which can be used for calibrating and testing applications.  

Ambient-like carbonaceous aerosols  

Our facility consists of a soot generator to produce fresh combustion particles and an oxidation flow reactor to simulate atmospheric processes by coating these soot particles with secondary organic matter. These synthetic aerosols are well-characterised with a wide range of physical and optical properties which could be used to calibrate and test air quality monitors and can also be used for health studies.  

Silver nanoparticles  

Many applications ranging from calibration of aerosol measurement instruments to fundamental aerosol research require a stable source of test particles with good repeatability. Silver nanoparticles are an ideal candidate because they do not contain any semi-volatile components and can be generated at very small sizes. Our traceable silver particle generation facility produces particle size distributions with an adjustable peak in the 2 – 70 nm range and a very stable particle number concentration (σ ≈ 1 % over 15 hours of operation). This novel source of nanoparticles will be used for the calibration of condensation particle counters (CPCs), differential mobility analyser (DMAs), and volatile particle removal (VPR) systems, and other research projects.  

Portable emissions measurement system testing 

Fine particulate matter (PM) and nitrogen oxides (NOx) emitted from vehicles are major sources of air pollution. Recent EU and UK legislations require real driving emissions (RDE) testing of vehicles using portable emissions measurement systems (PEMS) for on-road type approval, however metrological validation is lacking.  

The EMPIR MetroGoogle Earth vehicle in garage fixed with a portable emissions measurement device to monitor on-road pollutionPEMS project is a joint research project between several European NMIs and academic partners with metrological validation of PEMS as its primary goal. We are a key partner in this project, focussing on metrological characterisation and inter-comparison of PEMS in terms of particle number and NOx measurements. The project supports the accuracy and comparability of vehicle emission values and the development of the associated infrastructure for PEMS calibration services at NPL.


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