In larger installations {TAIL ~ a signal output} from an oxygen analyzer 9 feeds into controller 5 to automatically adjust {HEAD ~ the ratio} of reducing agent to adjust for any variation in oxygen content of the water being treated 
In larger installations { TAIL ~ a signal output } from an oxygen analyzer 9 feeds into controller 5 to automatically adjust { HEAD ~ the ratio } of reducing agent to adjust for any variation in oxygen content of the water being treated
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH