Proposal from the Particle Measurement Programme informal group to:
- Modify the existing solid PN measurement methodology having a 50% cut-off size at 23 nm (SPN23) in order to allow the use of catalyzed volatile particle remover (VPR) and introduce minor improvements, and
- Include as a second option a solid PN measurement methodology with a 65% cut-off size at 10 nm (SPN10).