The detector includes {HEAD ~ a microswitch} having {TAIL ~ a sensing arm} which contacts a center portion of an elastic membrane 
The detector includes { HEAD ~ a microswitch } having { TAIL ~ a sensing arm } which contacts a center portion of an elastic membrane
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH