Homebrew PCBs

"Jim Barnes" <jim@...> writes:
> It sounds like a ph meter may be a good addition to my lab. Does
> anyone have a good, CHEAP design for one that we could make into a
> PCB? J

I've never needed one.  CuCl becomes CuOH when the pH rises above 7,
and precipitates.  You can just watch and see, it's its own indicator.
If FeCl does the same thing, no pH meter needed.