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