System and method for unified sampling of particulate matter for reducing the dispersion of results in vehicle emissions tests

A sampling system of particulate matter for vehicle emission tests, the system comprising:

• a probe configured to sample vehicle emissions carrying particulate matter, the probe directing the sampled particulate matter into a channel of a plurality of channels;
• a filter holder positioned within at least one of the plurality of channels, wherein at least one of the plurality of channels does not include a filter holder;
• valves arranged and configured to direct the vehicle emissions into a specified channel of the plurality of channels;
• a sampling pump configured to flow the vehicle emissions through at least one channel of the plurality of channels;
• and
• a mass flow meter arranged to receive the vehicle emissions from the plurality of channels;
• a balloon configured to reduce pulsations in the mass flow meter caused by the sampling pump;
• a cylinder configured to reduce pulsations in the mass flow meter caused by the sampling pump;
• and
• a return arranged to direct the flow to a constant volume sampler.