On Wed, Sep 10, 2014 at 6:12 AM, Sean Breheny wrote: > I think that the OP needs to post a schematic or at least describe the > circuit better. Where are the probes connected to the circuit? > > My thoughts exactly. Also, what are the "probes"? With the right (wrong?) metals in salt solution overnight, I could easily see the surface corrosion having an effect. -Denny --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .