46. The Chair of the informal group on the Particle Measurement Programme (PMP) informed GRPE about the group’s activities (GRPE-63-26). He summarized the issues discussed during the last PMP meeting, giving details on the status of the Volatile Particle Removal (VPR) round robin, the Particle Number Counter (PNC) calibration experience, the European Metrology Research Project (EMRP), measurements of particles under 23 nm, and the status of the Heavy Duty (HD) round robin. He informed about the next steps (including discussions on the results of the round robin testing for VPR and HD, updates from the EMRP calibration work). He invited GRPE experts to give their views on the sub-23 nm particles measurement and he informed GRPE about the ongoing discussion on improving calibration procedures.

47. GRPE acknowledged the progress made by the group. The experts from France, Germany, the Netherlands, Switzerland and OICA supported the group’s request to act as a forum for discussion of further studies and to investigate measurement procedures for sub 23nm particles. The expert from France stressed the need to analyse the costs and benefits of this.

48. GRPE agreed that the group should meet in conjunction with its next session, in June 2012.