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