So as to verify compliance with limit values for harmful substances, large engines today must be tested in accordance with the regulations of the International Civil Aviation Organization (ICAO). Presently neither a standardized measuring method nor a standard exists with respect to particulate emissions (ultrafine particles). The invention relates to the creation of a standardized transport system having the lowest possible loss for measuring ultrafine particles of aircraft engines, which can be operated simultaneously with the harmful substance measurement of aircraft engines stipulated until now. Appropriate instruments for measuring the particle count, mass and size distribution can be connected to this transport system.