ORP schematic

[guido_kp]

Anyone have an orp schematic? Looking to add this capability to my arduino controller.

[stugray]

An ORP probe reading circuit should be almost exactly the same as a pH monitor.

However I believe that a ph uses an inverting amp and very low voltage (10s of mV).

The ORP reads out mV directly ( 400 ORP is 400 mV ).
So the amplifier gains may be different but they both need to be a very high input impedance ( look up instrumentation amp ).

Stu

[guido_kp]

Thanks Stu. I built the pH amp already Here (http://www.electro-tech-online.com/attachments/electronic-projects/21692d1218729019-ph-amplifier-micro-ph_amplifier.pdf) I kind of understand how it works, but not enough to change it to an ORP amp. Any takers on showing me? I'll do some reading on instrumentation amps in the meanwhile.