Patent ID: 11913859
Assignee: TEKNOLOGIAN TUTKIMUSKESKUS VTT OY
Field: Measurement (Instruments)
Classification: CPC G  B | IPC B  G

Claim 0:
1. A method comprising:
receiving a gas sample to a volume of an on-chip fine particle sensor;
generating by a microelectromechanical, MEMS, ultrasonic transducer a standing wave to the volume, said standing wave comprising at least one particle trapping zone for trapping particles carried by the gas sample; an
releasing, by the MEMS ultrasonic transducer, particles trapped to the at least one particle trapping zone by decreasing power of the standing wave to at least one lower power level, and/or switching off, by the MEMS ultrasonic transducer, the standing wave, wherein size of the released particles is controlled by the power level of the standing wave and/or a time the at least one particle trapping zone is switched off to release plural sets of particles at different times, each set having particles of a same size range,

wherein the on-chip fine particle sensor is configured to determine a particle size distribution of the gas sample on the basis of an arrival time distribution of the released particles.