"This proposal aims at the design and manufacturing of an instrument and a sampling system for the measurement of aerosol particles in the exhaust of vehicles and engines. Compared to commercial systems, the innovative elements of the current proposal are (1) the ability to measure both the mass and the number of particles in real time, (2) the possibility to measure both upstream and downstream of exhaust aftertreatment systems with constant dilution ratio, not affected by the aftertreatment backpressure, and (3) the compliance with the PMP requirements with respect to the treatment of the sample (heating, penetration, dilution ratio adjustment). The instrument and sampling system will be fully integrated and will be controlled by the same graphical user interface platform. The system will be able to perform measurements both in an engine test cell but also on-board a vehicle, so could be also considered a portable emission measurement system (PEMS). Such an instrument is expected to be a global performer in exhaust particle measurements. The success of the project is based on the strong partnership of an aerosol measurement instrument manufacturer (Dekati, Ltd – Finland), a mechanical engineering university lab with long experience in automotive exhaust measurements (LAT/AUTh - Greece) and a vehicle manufacturer which can provide the experience for the final validation of the instrument. The proposal requires a strong collaboration between mechanical engineers and aerosol experts from the very first stages of instrument development to make sure that the principles and the implementation of the instrument will be fully compatible with the engineering requirements set by the regulations and the practical limitations of the instrument use in an engine measurement facility or on-board a vehicle. The implementation of the project is also expected to foster a long-term collaboration of the partners in the area of instrument and sampling techniques development."