The digital processor is adapted to modify {HEAD ~ the potential} to maintain {TAIL ~ the current} inside a predetermined range such that the potential is representative of the solution pH when the current is inside the predetermined range 
The digital processor is adapted to modify { HEAD ~ the potential } to maintain { TAIL ~ the current } inside a predetermined range such that the potential is representative of the solution pH when the current is inside the predetermined range
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH