Patent ID: 9541488
Date: 2017-01-10
CPC Classifications: G01N

Claim:
1. An apparatus for measuring particles in a gas, said apparatus comprising: an inlet for said gas to enter provided with a first mechanism to separate the gas into two or more flow paths, the mechanism configured to remove coarse particles larger than a first selected size and direct the gas with the coarse particles along a first flow path and permitting smaller particles of less than the first selected size to pass through the mechanism to a second flow path; a second mechanism to subsequently separate the gas along one of the two or more flow paths to remove coarse particles larger than a second, smaller selected size permitting gas flow with smaller particles of less than the second selected size to pass through, the second mechanism positioned downstream of the inlet; a first chamber containing a first quartz crystal sensor on which particles of less than one of the first or second selected size can deposit to create an output signal in response to a deposited particle mass, wherein said first chamber is maintained at a temperature sufficient to prevent vapor condensation on said first sensor; and a second chamber containing a second quartz crystal sensor and said second chamber for charging particles of less than the other of the first or second selected size with ions generated in a corona discharge and depositing the charged particles on the second quartz crystal sensor to generate an output signal in response to the deposited particle mass.