Erik:
I didn't say it HAD to be used. I also did not pin down the application to one of it being used for a tachometer. I was just pointing out that there are optical technologies that are useful in an industrial setting.

If you are making a conveyor or product handler there are very well likely times where an optical shaft encoder is just the ticket for use. I have had to use them many times. There are also a multitide of other technologies as well, each suited to its own particular application or capabilities.

It is best to evaluate each requirement or need based on all factors than just reject a possible solution out of hand.

Michael Karas


.