The flux of particles collected by scientific low energy detectors are sensitive to absolute and differential potentials, and may include both ambient and secondary particles emitted by the spacecraft itself. This work presents numerical models of particle detector behaviour on Solar Orbiter, using the SPIS software. The results presented in this paper show the necessity to take into account the spacecraft plasma interactions at the earlier stage of scientific missions' definition, as well as during measurement interpretation. It demonstrates that electrons emitted in the vicinity of the detectors may be the main contributor to low energy electron measurements pollution.