PARTICLE MASS SPECTROMETER FOR DETECTING NANOPARTICLES AND METHOD

摘要

Gas-borne particles are removed from an aerosol source by a multistage molecular beam system. In the high-vacuum part of the particle mass spectrometer, the particle beam flies through a deflection capacitor having a variable electric field. The part of charged particles is separated according to polarity and ratio of kinetic energy and charge. The charged particles reach the charge detector or charge detectors, Faraday cups for example, and respectively produce a current or voltage signal which is multiplied proportionally, in relation to the captured figure, by the charge figure. The particle speed is also measured such that the measuring data can be processed to form a mass spectrum. By assuming the simple charge per particle and the spherical shape, the mass spectrum can be converted into a size spectrum.