Identification of inorganic compounds of dust and their effects on electrical contact failure

The inorganic compounds in the airborne dust collected indoors at Beijing University of Post and Telecommunications has been analyzed by jointly using X-ray powder diffraction (XRPD), electron probe microanalysis (EPMA) and transmission electron microscopy (TEM). The results showed that the dust was composed of up to 24 compounds, including quartz, feldspar, mica and calcite etc.. The distilled water separation method effectively enabled size separation of airborne particles. In analysis of airborne particles, combined application of three methods, i.e., XRPD, EPMA and TEM, can provide comprehensive and reliable results. In the studies of dust contamination on electrical contacts, soft dust particles may contribute to the electrical contact failures; their effects can not be ignored.