The integrated photodiode will contain photosensitive sections (matrix) according to the mathematical BESSEL function. The sections should be well suited to the expected light intensity distribution in order to obtain the full dynamic range. Analog preprocessing will be used to determine the symmetry, catch the moment where the particle is at the center of the excitation beam and the pattern characteristic of the excitation light is maximum. The central area of the photodiode must be optically inactive in the form of a metallized layer (where the light is focused when there is no scattering by particles). In this region, the ray should be reflected directly. This can be used for a feedback loop to stabilize the signal power from the LED.

Parallel to the mathematical evaluation, a microcontroller will be defined and individual algorithms programmed to evaluate the signal data from the special photodiode used. A protocol will be developed that must be flexible and allow dynamic gain adjustment with respect to the photodiode segments. The microcontroller will be able to determine the size of the particles and count them separately. It gives information about the size distribution and the total number of particles that will be calculated from the airflow. According to the class PM2.5 and PM10 it will be possible to calculate and control the exceeding of the limit value.