Abstract: A detection apparatus includes four sets of transmitter and receiver wherein the transmitters are on a first sliding member of a frame and the receivers are on a second sliding member of the frame; and drives for moving the first and second sliding members back and forth. During the movements of the first and second sliding members, each transmitter emits laser beam toward the receiver of the same set by passing through a space above a photoresist-coated optical glass by 100 ?m, no signal is generated at the receiver if the laser beam is not blocked, and a signal is generated at the receiver if the laser beam is blocked by at least one of a plurality of particles on the photoresist-coated optical glass.

Abstract: A system for monitoring track transportation to determine an abnormal status of a track is disclosed. The system includes at least one sensing module arranged at a predetermined monitoring point of the track, and each sensing module includes at least one force sensing unit and vibration sensing unit. A track status signal processing circuit is electrically connected to the sensing module for receiving the time domain force-related signal and time domain vibration-related signal, and these signals are converted to the digital signals. The digital signals are transferred to a signal calculating and processing unit, which includes a time domain/frequency domain force-related signal converting circuit, a time domain/frequency domain vibration-related signal converting circuit, and a frequency response function calculating unit.