Harmonizing the Sampling and Ambient Air Monitoring

In any scientific field it is difficult (and sometimes impossible) to compare the results of two experiments when the experiments utilized different methods. Measuring ultrafine particles in the atmosphere is no different: multiple available options for sampling, measurement, and data reporting can result in data that feels like a burden, rather than providing the insights you need into air quality.

The European Standards Committee (CEN) understands this problem, and has created two standards to help ‘harmonize’ the sampling and measurement of atmospheric particles, as well as the measurement data itself. These two standards are EN 16976 (formerly known as CEN/TS 16976), and CEN/TS 17434:2020.

Particle Number Concentration

The European standard EN 16976 describes the use of Condensation Particle Counters (CPCs) to determine atmospheric aerosol number concentrations. The standard specifies performance criteria for a CPC (for example: linearity, counting efficiency, and flow rate), and also specifies test how its performance should be tested. EN 16976 also requires that all CPCs be calibrated according to ISO 27891:2015.

Ultrafine Particle Size Distribution

Determining the ultrafine particle size distribution (PSD) is described in CEN/TS 17434:2020. In this standard, the method ‘Mobility Particle Size Spectrometer’ (abbreviated as ‘MPSS’) is used to cover a size range from 10 nm to 800 nm. TSI’s Scanning Mobility Particle Sizer™ (SMPS™) spectrometer fits this need, and has been making ambient air measurements worldwide for years.

Ambient Air Sampling

Delivering a sample of ambient atmospheric particles to these instruments, however, is not a trivial matter. Wind conditions, humidity and diffusion losses all make it challenging to continuously collect a representative sample of atmospheric particles. Because of this, both EN 16976 and CEN/TS 17434 specify how the particles must be sampled and conditioned prior to measurement. TSI’s Sampling System for Atmospheric Particles meets these requirements. The sampling system can be used with a CPC, an SMPS™, or both simultaneously. 

Based on decades of particle measurement experience, TSI will continue to serve the ambient monitoring community – even as regulations change and science evolves.