Homebrew PCBs

grantfair2001 wrote:
> 
> I built an autotitrator with a chemistry student some years back. It
> used a syringe pump driven by a stepper. We were dropping NaCl
> solution into silver nitrate IIRC (I supplied mechanical/electronic
> assistance, he did the chemistry). The probe was expensive but he
> borrowed it from the school. Would there be a probe which would
> detect the endpoint in this case? Or would visual inspection be just
> as good - in terms of time required?
> 

I can't think of anything quicker simpler than titrating with a pipette 
or a long length eye dropper. The good news is we only need a ball park 
figure of acid and it seems anything > 1M is good while < 0.1M is not so 
good.
See if you can get a long eye dropper that has a measuring mark about 
half way up. Just take one sample of etchant into a glass jar, with some 
water, then using same eye dropper take one sample of 1M NaOH. Drip into 
glass gar until copper precipitate forms. Note relative how much NaOH 
was used and thats your approximate acid molarity.

Adam