Each is connected to {HEAD ~ an adjustable amplitude precision current source} of fixed frequency and {TAIL ~ an oversampling type digital voltmeter} 
of
Each is connected to { HEAD ~ an adjustable amplitude precision current source } of fixed frequency and { TAIL ~ an oversampling type digital voltmeter }
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL