{HEAD ~ The sensor} includes a light source transmitter and a receiver sensitive to the radiation emitted by the transmitter to be located on a diametrically opposite surface area portion of {TAIL ~ the body protruding part} 
{ HEAD ~ The sensor } includes a light source transmitter and a receiver sensitive to the radiation emitted by the transmitter to be located on a diametrically opposite surface area portion of { TAIL ~ the body protruding part }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL