The PMPD dilution system is used for emission measurements of vehicles and jet engines.
The PMPD system is a dilution system according to the ejector principle that was especially developed for the PMP application or the PMP measurement chain.
The Particle Measurement Programme or PMP is a programme for advancing the particle measurement technique for particulate vehicle exhaust gases.
The PMPD consists of a vaporisation line heated to 200°C, a dilution line also heated to 200°C, the thermodiluter to remove volatile particles, followed by a second unheated dilution step. Each dilution step has a dilution factor of 1:10, which corresponds to a total dilution factor of 1:100.
The efficiency of removing volatile particles was determined at METAS with 30 nm sized tetracontane (C40H82) droplets in accordance with "VPR Calibration Procedure AEA / ED47382 / Issue 5" (Volatile Particle Removal Efficiency) and is 0.99967.