초록 ▼

A method and apparatus are provided for measuring the aerodynamic particle size distribution of airborne particles by drawing the particles through a device 10a which continuously or intermittently changes the aerodynamic cut of the particles entering an aerosol sensor. Sensing is performed by optic

A method and apparatus are provided for measuring the aerodynamic particle size distribution of airborne particles by drawing the particles through a device 10a which continuously or intermittently changes the aerodynamic cut of the particles entering an aerosol sensor. Sensing is performed by optical sensors 16 such as aerosol photometry or optical single particle size spectrometry or by other sensors that measure particle concentration remaining in the aerosol flowing from the cut device. Preferably, the cut device includes a rotational element 22 that centrifugally removes particles of larger aerodynamic size than that determined by a cut setting, which can be varied by varying the rotational speed of the cut element. Preferably also, the rotary element does not alone determine the flow rate of the aerosol through the cut device, but a separate pump 40 or flow restriction controls the time the aerosol remains in the cut device and maintains the flow rate through the device at a preferably constant level.

대표청구항 ▼

1. A method for determining the concentrations, in an aerosol that includes air and airborne particles, of the airborne particles as a function of their aerodynamic particle sizes. the method comprising the steps of:flowing aerosol into an aerodynamic cut device having a rotating element that at suc

1. A method for determining the concentrations, in an aerosol that includes air and airborne particles, of the airborne particles as a function of their aerodynamic particle sizes. the method comprising the steps of:flowing aerosol into an aerodynamic cut device having a rotating element that at successively higher rotational speeds makes aerodynamic cuts at successively smaller aerodynamic particle sizes by centrifugally removing particles larger than the respective aerodynamic cut; flowing particles smaller than the aerodynamic cut size into an optical sensor; and with said optical sensor, recording aerosol concentrations as a function of the aerodynamic particle sizes determined by said aerodynamic cut device.