Patent ID: 7034549

Claim:
A device for detecting airborne conductive or dielectric particles, comprising: a resonant cavity having a high E field sensing region; means for feeding power to the cavity; a suction device for directing an airborne particle through the high E field sensing region of the cavity; sensing means coupled to the cavity for sensing a drop in E field level caused by the particle and outputting an output signal representative thereof; and means for displaying a histogram of the effective conductivity of airborne conductive particles comprising: means for measuring the height of each signal outputted by the sensing means per unit time; means for counting the number of signals of a given height as a count that is output by the sensing means per unit time; a memory storage register having an address number proportional to signal height; means for storing the count in the memory storage register at the respective address number; and means for displaying the count from each address number of the memory storage register as a function of address number.