Lost in a loop

[bce123]

while on site today i noticed that some of the sensors wont work for my app. the photo sensors are falsely triggered by steam rolling out the end of the pipe due to the upstream quench system and the heating of the pipe at the preheat coils. I think I will have to add an encoder just before the coils to handle the trailing end detction up to the coils. I could incorprate it into the leading edge speed I suppose

 

[bce123]

also proxes wont work because the purpose of this detection is to catch badly warped pipes from hiting the coils. could be as much as 6" difference!!