| 摘要 |
PURPOSE: To detect from radio frequency signals the amount of particulate materials accumulated on a filter medium constructed of a dielectric material and placed inside a container. CONSTITUTION: The accumulated state of particulate materials is monitored by measuring the transmission loss of radio frequency signals in the area of the longitudinally overlapping portions of a signal-transmission input antenna 20 which has at least one antenna element extending in the longitudinal direction of a container and which is placed inside a filter medium and an output antenna 22 which has at least one antenna element extending in the longitudinal direction of the container and which is placed inside the filter medium to receive the signals transmitted from the input antenna 20, and the result is output. |
