Apparatus for analyzing the particulate matter content of an aerosol

A method for operating an apparatus,

• the apparatus comprising:
• an aerosol chamber, formed between a first substrate and a second substrate, which is configured to receive an aerosol comprising particulate matter content to be analyzed;
• an ultrasonic generator which is configured to produce ultrasonic waves in the aerosol received in the aerosol chamber;
• an ultrasonic detector which is configured to detect ultrasonic waves produced by the ultrasonic generator in the aerosol;
• and
• an evaluator having a data exchange communication link with the ultrasonic detector and being configured to ascertain the particulate matter content of the aerosol based on signals output by the ultrasonic detector;
• wherein the ultrasonic generator is arranged on a side of the first substrate and the ultrasonic detector is arranged on the side of the first substrate, wherein the side of the first substrate faces the aerosol chamber;
• and
• wherein the ultrasonic generator is configured to emit ultrasonic waves in a principal propagation direction perpendicular to the side of the first substrate on which the ultrasonic generator is arranged;
• wherein aerosol chamber further comprises a deflection area that is substantially planar, extends along a deflection area plane, and is configured to deflect to the ultrasonic detector, the ultrasonic waves emanating from the ultrasonic generator;
• and wherein a principal ultrasound emission direction of the ultrasonic generator includes an angle not equal to 90° with the deflection area plane;
• the method comprising:
• operating the ultrasonic generator for producing ultrasonic waves in an aerosol received in the aerosol chamber;
• detecting ultrasonic waves by means of the ultrasonic detector;
• outputting signals characterizing the detected ultrasonic waves to the evaluator;
• and
• ascertaining the particulate matter content of the aerosol by the evaluator from the signals output by the ultrasonic detector.