Patent ID: 7712384

Claim:
An apparatus for diluting a gas sample, the apparatus comprising: a sample gas conduit having a sample gas inlet end and a diluted sample gas outlet end; an orifice plate forming a sample gas flow restricting orifice disposed proximate said sample gas inlet end connected with said sample gas conduit and providing fluid communication between an exterior and an interior of said sample gas conduit; a diluted sample gas conduit disposed within said sample gas conduit having a mixing end with a mixing space inlet opening disposed proximate said sample gas inlet end forming an annular space between said sample gas conduit and said diluted sample gas conduit, said mixing end disposed at a distance from said sample gas flow restricting orifice; dilution gas means for introducing a dilution gas into said annular space; filter means for filtering said sample gas connected with said sample gas inlet end of said sample gas conduit; and a first tube disposed within said diluted sample gas conduit having a first tube inlet end disposed proximate said sample gas flow restricting orifice upstream of said mixing end of said diluted sample gas conduit.