Collecting device for collection of particles, a sample collector, and an analysis instrument

A collecting device for collection of particles and presentation of collected particles for analysis, said collecting device comprising:

• a first layer and a second layer, wherein the first layer and the second layer are arranged to be spaced apart for defining a particle collection chamber between the first and the second layer, wherein the particle collection chamber has a first and a second side defined by the first layer and the second layer, respectively;
• wherein the first layer comprises a first surface configured to receive a flow of air carrying airborne particles and a second surface facing the second layer, wherein the first layer comprises a plurality of inlet nozzles having a first end at the first surface of the first layer and a second end at the second surface of the first layer, wherein the inlet nozzles are configured to extend through the first layer for transporting the flow of air therethrough from the first end to the second end;
• wherein the second ends of the inlet nozzles are configured to face a first surface of the second layer for capturing airborne particles in the flow of air entering the particle collection chamber through the second ends of the inlet nozzles by impaction of airborne particles on the first surface of the second layer;
• wherein the second layer comprises a plurality of outlet nozzles, wherein the outlet nozzles have a first end at the first surface of the second layer and a second end at a second surface of the second layer and the outlet nozzles are configured to extend through the second layer for transporting the flow of air therethrough from the first end to the second end, wherein a position of the first ends of the outlet nozzles is shifted with respect to a position of the second ends of the inlet nozzles such that the outlet nozzles are not collinear with the inlet nozzles;
• wherein the collecting device is configured to provide optical access for performing a measurement, based on light, of airborne particles collected in the particle collection chamber at a first measurement position arranged such that the second layer is between the second side of the particle collection chamber and the first measurement position or at a second measurement position, which is arranged at an opposite side to the first measurement position in relation to the second side of the particle collection chamber.