The principles of the present invention are particularly useful in an optical arrangement generally indicated at 20 for {HEAD ~ use} with {TAIL ~ a passive infrared motion detector} for monitoring a space 
with
The principles of the present invention are particularly useful in an optical arrangement generally indicated at 20 for { HEAD ~ use } with { TAIL ~ a passive infrared motion detector } for monitoring a space
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH