Optical level switches
 

ANyone familiar with these? Or a better, less expensive option?

W.E. Anderson OLS Level Switch, the cheapest optical ones I could find. I would like to add a couple of these for fail safe shutoff for my RO tanks.

Charles

we use something like this for our swimming pools in the surge tanks. the only thing I can say is you will have to run it in a tube or something because the laser can bounce off debris or items and cause and incorrect reading. I just use cheap float valves myself and never had an issue.

I ended up making my own.

Digikey has a decent article on it. I used it do design mine.
http://www.digikey.ca/en/articles/te...nic-techniques