An external backing material matched to the acoustic impedance of the CdS crystal is attached to {HEAD ~ the electrode} connected to {TAIL ~ the signal processing system} 
connected to
An external backing material matched to the acoustic impedance of the CdS crystal is attached to { HEAD ~ the electrode } connected to { TAIL ~ the signal processing system }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL