EU imposes the stricter limits on particle number-based emissions (PN) in the world. These limits refer to solid-only particles with sizes above 23 nm, however, since there is strong evidence of significant solid particles below 23 nm, especially for modern gasoline direct injection (GDI) engines, these are serious considerations to also regulate <23 nm particles, down to at least 10 nm. Nevertheless, the current procedures for sampling and measurement of nanoparticle emissions are based on the Particle Measurement Protocol (PMP) consisting of two dilution stages and a volatile particle removal (VPR) device, usually an evaporation tube (ET) for which there is strong evidence that for smaller particle sizes it introduces particle artefacts and/or significant losses. SUREAL-23 is an EU funded project aiming at the characterisation and measurement of sub-23 nm particles. One of the primary targets of the project is to design and realize effective and accurate sampling and conditions systems for the precise measurement of such emissions. In this work, we will present the development of optimised systems introducing novel approaches such as the incorporation of a catalytic stripper (CS), instead of the ET and the implementation of measurements under hot conditions.