I would like to build a PIC based Redox measurement unit. I could not find any information about the signal conditioning path. I know that AC over DC is a preferred method. What about frequency range, and voltage required. What signal magnitude (uV vs mV) can be expected from the probe? I would appreciate any comments. Janusz -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.