The output signal from {TAIL ~ this optical detector} 7 is sent via the preamplifier to the RMS DC 18, which converts {HEAD ~ the amplitude} into a dc voltage 
The output signal from { TAIL ~ this optical detector } 7 is sent via the preamplifier to the RMS DC 18 , which converts { HEAD ~ the amplitude } into a dc voltage
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH