pH probes are very temperature dependent so you will need to also have a temperature input that is accurate to .1 F. Then your software will have to calibrate it's readings. This is all pretty doable the only problem I forsee is the very short life expectancy of common pH probes. There are some industrial processes that require constant pH monitering and use more robust probes but they ar very expensive. On cheap probes I wear them out in a year of using them for 10 minutes a day and storing them in storage solution and needs calibration daily. My good meter has had the same probe for 6 years and is still in calibration from 2002.
It has been a long time since I was taught how a pH probe works. But if I have any old grey matter left, I think the probe is a current source and not a voltage source.
Edit: This link shows it as a voltage source:
http://www.ph-meter.info/pH-meter-construction
It has been a long time since I was taught how a pH probe works. But if I have any old grey matter left, I think the probe is a current source and not a voltage source.
Edit: This link shows it as a voltage source:
http://www.ph-meter.info/pH-meter-construction
