Apparatus and method for measuring particles in polydispersed systems and particle concentrations of monodispersed aerosols

A method for measuring any of the size, charge, velocity and concentration of particles in polydispersed systems, and particle concentrations of monodispersed aerosols, including the steps of:

• conducting the particle flow through at least one active field sensor operating by induction;
• measuring charges of electrostatic induction of particles passing the sensor as induced on the active field sensor and transmitting the resulting measurement of induction for each particle passing the sensor to an active charge amplifier which provides an output signal;
• and
• transmitting the output signal of the active charge amplifier to a measured value indicator;
• wherein said steps are performed so as to measure the particle concentrations of monodispersed aerosols at a grain size range from about 10 nm to about 500 nm at concentrations from about 10.sup.14 to about 10.sup.6 parts/m.sup.3, wherein the aerosol particles are electrically charged by a diffusion charging process and the charge thereof is discharged by electrostatic induction to active D sensors used to measure said charge.

A method for measuring any of the size, charge, velocity and concentration of particles in polydispersed systems, and particle concentrations of monodispersed aerosols, including the steps of:

• conducting the particle flow through at least one active field sensor operating by induction;
• measuring charges of electrostatic induction of particles passing the sensor as induced on the active field sensor and transmitting the resulting measurement of induction for each particle passing the sensor to an active charge amplifier which provides an output signal;
• and
• transmitting the output signal of the active charge amplifier to a measured value indicator;
• wherein said steps are performed so as to measure the particle concentration in polydispersed systems in the grain size range from about 10 nm to about 500 nm at concentrations from about 10.sup.14 to about 10.sup.6 parts/m.sup.3 based on particle separation of charged aerosol particles in the polydispersed system dependent on particle size, by action of electric field forces with variation of the separation and charging conditions, wherein simultaneous remaining space-charge is measured by active D-sensors to determine the particle size distribution and concentration of the aerosol.

A method for measuring any of the size, charge, velocity and concentration of particles in polydispersed systems, and particle concentrations of monodispersed aerosols, including the steps of:

• conducting the particle flow through at least one active field sensor operating by induction;
• measuring charges of electrostatic induction of particles passing the sensor as induced on the active field sensor and transmitting the resulting measurement of induction for each particle passing the sensor to an active charge amplifier which provides an output signal;
• and
• transmitting the output signal of the active charge amplifier to a measured value indicator;
• wherein the particle flow is conducted through a pipe made of electrically highly insulating material and electrostatic charges of the particles are induced on at least one annular sensor at the circumference of the pipe.

A method for measuring any of the size, charge, velocity and concentration of particles in polydispersed systems, and particle concentrations of monodispersed aerosols, including the steps of:

• conducting the particle flow through at least one active field sensor operating by induction;
• measuring charges of electrostatic induction of particles passing the sensor as induced on the active field sensor and transmitting the resulting measurement of induction for each particle passing the sensor to an active charge amplifier which provides an output signal;
• and
• transmitting the output signal of the active charge amplifier to a measured value indicator;
• wherein, for measuring the flow velocity of a particle flow in a pipe, ions, electrons or charged dust particles entrained without slippage in an air stream are used for signal generation;
• wherein signals of two annular sensors placed at a distance from each other are measured;
• and wherein average flow velocity is then determined from a time lag of individual signals.

A method for measuring any of the size, charge, velocity and concentration of particles in polydispersed systems, and particle concentrations of monodispersed aerosols, including the steps of:

• conducting the particle flow through at least one active field sensor operating by induction;
• measuring charges of electrostatic induction of particles passing the sensor as induced on the active field sensor and transmitting the resulting measurement of induction for each particle passing the sensor to an active charge amplifier which provides an output signal;
• and
• transmitting the output signal of the active charge amplifier to a measured value indicator;
• wherein, for measuring the flow velocity of a particle flow in a pipe, ions, electrons or charged dust particles entrained without slippage in an air stream are used for signal generation;
• wherein signals of two annular sensors placed at a distance from each other are measured;
• and wherein average flow velocity is then determined from the correlation of at least two sensor signals.