Passive aerosol diluter mechanism

A method of diluting a sampled aerosol stream, the method comprising:

• receiving a sample of an aerosol stream at a primary diluter, the primary diluter device having a first inlet coupled pneumatically downstream from an aerosol sample inlet and a second inlet to accept a filtered portion of a portion of the sampled aerosol stream;
• combining, in the primary diluter device, the filtered portion with an additional sampled aerosol stream received from the aerosol sample inlet;
• splitting, within a flow diverter device, at least the sampled aerosol stream into a first portion of the sampled aerosol stream and a remaining portion of the sampled aerosol stream;
• and
• filtering the remaining portion of the sampled aerosol stream and providing a filtered aerosol stream to the second inlet of the primary diluter device.

A tangible computer-readable storage medium having no transitory components and storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• receiving a sample of an aerosol stream at a primary diluter, the primary diluter device having a first inlet coupled pneumatically downstream from an aerosol sample inlet and a second inlet to accept a filtered portion of a portion of the sampled aerosol stream;
• combining, in the primary diluter device, the filtered portion with an additional sampled aerosol stream received from the aerosol sample inlet;
• splitting, within a flow diverter device, at least the sampled aerosol stream into a first portion of the sampled aerosol stream and a remaining portion of the sampled aerosol stream;
• and
• filtering the remaining portion of the sampled aerosol stream and providing a filtered aerosol stream to the second inlet of the primary diluter device.

A passive aerosol diluter system, comprising:

• an aerosol sample inlet to receive a sample of an aerosol stream;
• a primary diluter device having a first inlet coupled pneumatically downstream from the aerosol sample inlet and a second inlet to accept a filtered portion of a portion of the sampled aerosol stream, the primary diluter device to combine the filtered portion with an additional sampled aerosol stream received from the aerosol sample inlet, the first inlet and the second inlet comprising a portion of a recirculating dilution portion of the passive aerosol diluter system;
• a flow diverter device coupled pneumatically downstream of the primary diluter device to split at least the sampled aerosol stream into a first portion of the sampled aerosol stream and a remaining portion of the sampled aerosol stream;
• a filter coupled pneumatically downstream of and in fluid communication with the flow diverter device to receive the remaining portion of the sampled aerosol stream from the aerosol sample inlet to provide a filtered aerosol stream to the second inlet of the primary diluter device
• a secondary dilution-flow orifice and mixing portion coupled pneumatically downstream from the flow diverter device to receive the first portion of the sampled aerosol stream from the aerosol sample inlet, the secondary dilution-flow orifice and mixing portion including a tee to receive and split flow from the first portion of the sampled aerosol stream into a first fraction and a remaining second fraction;
• a mixing portion flow-monitoring device coupled pneumatically downstream of the tee to receive the first fraction of the sampled aerosol stream, the flow-monitoring device being configured to allow for a passage of particles contained in the sampled aerosol stream;
• and
• a filter pneumatically coupled downstream of the tee and in parallel with the flow-monitoring device, the filter to remove at least a portion of aerosol particles from the second remaining fraction of the sampled aerosol stream, thereby producing a filtered stream, an outlet of the filter coupled to an outlet of the mixing portion flow-monitoring device to recombine the filtered stream with the sampled aerosol stream, creating a more diluted aerosol stream than the diluted aerosol stream received from the first fraction of the sampled aerosol stream.