Dust Particle Counter (SP-1)

Description

This instrument (SP-1) consisted of three piezo-element detectors mounted on a special metallic plate to measure the amplitude of the wave generated by dust particles heavier than 1E-10 g impacting on the plate. The amplitude was proportional to the mass of the dust particle. From the arrival time of the pulse at the three detectors, the coordinates of the impact point could be determined. The dead time of the instrument depended on the acoustic decay of the signal in the piezo-elements and could turn out to be significant. The counter was oriented in the direction of the relative velocity vector.