| 摘要 |
<p>A device (10) and method for monitoring particulate (22) flowing through a conduit (20) has a transmitter (16) and a receiver (18) positioned in optical alignment on opposite sides of the conduit (20). A light beam (50) is transmitted across conduit (20) from the transmitter (16) to the receiver (18). Particulate (22) flowing through conduit (20) interrupts light beam (50) causing a signal to be generated from which particulate concentration is determined. A calibrator assembly (40) has a motor (64) adapted to move a filter (100) having a selected percentage opacity within the path of light beam (50). Movement of the filter (100) modulates light beam (50) and a signal corresponding to the concentration associated with the percentage opacity is generated.</p> |
