| 摘要 |
A system for measuring particulate concentrations includes a mass sensing device (10). Mass sensing device (10) has a sensing chamber (16) with an intake port (12) and an output port (30). Sensing chamber (16) is divided into an upper portion (14) and a lower portion (18) by a filter membrane (20) which is a planar, peripherally supported filter for entrapping the particulates. The system further features harmonic excitation driver (24) for oscillating the filter perpendicular to its planar surface and a sensor (27) for measuring the frequency of oscillation. |
