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Unread 04-30-2003, 12:48 PM   #25
TerraMex
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Join Date: Nov 2002
Location: Portugal, Europe
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Ungh, i hate 6am posts. Big "no no" in the earlier post.

The use of a vertical mouting scheme on a IR emitter/ IR photo transistor doesnt work because the sensor reads the intensity of the light reflected on the water surface, not the time it takes to get there. So , in a vertical mount, there is little or no variation on the intensity. Only in an angular mount it can change with the change of the level. The angle of the refracted light changes and so does the intensity reaching the IR receiver. Thus reading a variation on the water level.

Of course, we're assuming there isnt any foam , bubbles or alot of agitation .
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