Atualy, we have an application witch we have to read the position (distances) of a wood log put transversaly between two fences.

We use a row of photocells placed at approximately 6" between each one on a distance of 18'-0" or more and the signal of the blocked photocells give us where is located the log. A lot of those applications are outside and there is a lot of troubles with photocells and sun reflexion.

The result on the second part of this process tell us that we need more reading precision. The easiest way seems to put more photocells but that makes the cost of our design and the adjusting works to expansive.

We are wondering if there is an other way than optical to make that application or is there an optical device more simple and adapted for what we want to do.

note: logs are always mooving.