Patent ID: 9714895
Date: 2017-07-25
CPC Classifications: F01N,G01N

Claim:
1. An apparatus for monitoring fine particle concentration in a flow of exhaust in a flowpath in a duct of an exhaust system of a combustion engine, comprising: a) a stem that attaches and seals the apparatus to the exhaust system through a single opening in a wall of the exhaust system; b) an inside part that has a single-walled housing and is arranged to be installed inside the duct of the exhaust system through the single opening in the wall of the exhaust system in an arrangement in which the entirety of the single-walled housing directly faces the flowpath in the duct; c) a particle measurement sensor that is inside the single-walled housing of the inside part; d) a gas inlet that is on the single-walled housing of the inside part, provides at least a part of a measurement flow to the particle measurement sensor, and is positioned within the duct such that there is no direct line-of sight route for particles flowing through the duct to enter the single-walled housing; e) a corona discharge device that is inside the single-walled housing of the inside part and ionizes essentially clean gas and separately provides essentially clean ionized gas to the particle measurement sensor, the clean ionized gas charging at least a fraction of the particles in the measurement flow; and f) a gas outlet that is on the single-walled housing of the inside part, through which the measurement flow exits the single-walled housing after passing the particle measurement sensor; and g) an outside part that is arranged to extend from the single opening of the wall of the exhaust system outside the wall of the exhaust system.