摘要 |
An elongated level sensor system has an optical prism formation moulded or cut in a side, and includes a plurality of LED light sources and corresponding photocells positioned along its length. Light from the LED sources are reflected off the prism surfaces to respective photocells when there is no liquid present in the area, thereby indicating "no liquid media present." When liquid surrounds a particular section, light from the LED is not reflected from the prism surfaces, but is refracted out; the change in photocell voltage then indicates the presence of liquid media. The system can be used in a plurality of liquid storage areas, and read out simultaneously at a remote sensor/alarm panel.
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