Method for the measurement of aerosol particles in gaseous samples
AssigneeAVL List GmbH
InventorsFriedrich Radke, Peter W. Krempl, Christian Reiter
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Abstract
A process to determine aerosol particles in gaseous samples, specifically in the exhaust of diesel motors, includes the at least indirect deposit of aerosol particles on a piezoelectric oscillating crystal and the determination of the oscillation parameters of the piezoelectrically stimulated oscillation of the crystal. In order to assure the required reproducibility reliably and independently of the type of aerosol particles, and thus to achieve a high quality of measurements, the piezoelectric crystal is charged to oscillation during less than half the period of deposit of aerosol particles.
Claims18
A method for the measurement of aerosol particles in gaseous samples, comprising the steps:
- at least indirectly depositing aerosol particles on a piezoelectric oscillating crystal for a deposition period;
- exciting crystal oscillations for a scanning duration;
- determining oscillation parameters of a piezoelectrically stimulated oscillation of the crystal during said scanning duration,
- said excitation of the crystal oscillation being done during the deposition period;
- and said scanning duration being less than half the deposition period.
A method for the measurement of aerosol particles in gaseous samples, comprising the steps:
- at least indirectly depositing aerosol particles on a piezoelectric oscillating crystal,
- exciting crystal oscillations for a scanning duration:
- determining oscillation parameters of a piezoelectrically stimulated oscillation of the crystal during said scanning duration to achieve a measurement value,
- leading at least a portion of the sample into a second apparatus that continuously takes measurement values,
- where at least one of the measurement values is gravimetrically calibrated by at least one of the measurement values that were determined by the oscillation parameter of the piezoelectrically excited oscillations of the crystal.
Dependencies are inferred from the claim text.