When member 215 is forced open by gas pressure, {HEAD ~ the current} flowing between electrode 240 and {TAIL ~ electrode} 242 is interrupted 
flowing between
When member 215 is forced open by gas pressure , { HEAD ~ the current } flowing between electrode 240 and { TAIL ~ electrode } 242 is interrupted
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH