The Dekati^® ELPI^®+ (Electrical Low Pressure Impactor) is a widely-used and well-characterized particle size spectrometer for real-time particle measurements. The ELPI^®+ enables measurement of real-time particle size distribution and concentration in the size range of 6 nm – 10 μm at 10 Hz sampling rate. The measurement method of the ELPI^®+ is the same for all the particle sizes, making the ELPI^®+ the only instrument available in the market that operates in such a broad particle size range using only one measurement technique. Since the ELPI^®+ also operates in a wide particle concentration range, it is well suited for both high and low concentration applications such as environmental air quality or direct combustion source measurements. The ELPI^®+’s robust structure is designed to be