{HEAD ~ The sensor} includes a light source and a receiver which is sensitive to {TAIL ~ its radiation} 
{ HEAD ~ The sensor } includes a light source and a receiver which is sensitive to { TAIL ~ its radiation }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL