A ratio of {HEAD ~ IP/IA} of {TAIL ~ the currents} flowing in the terminals P and A is detected 
of
A ratio of { HEAD ~ IP / IA } of { TAIL ~ the currents } flowing in the terminals P and A is detected
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH