The aluminium foil membrane has a mylar™ backing which enables the foil to withstand the pressure difference across it due to {HEAD ~ the gaseous environment} outside {TAIL ~ the chamber} and the substantial vacuum within 
outside
The aluminium foil membrane has a mylar ™ backing which enables the foil to withstand the pressure difference across it due to { HEAD ~ the gaseous environment } outside { TAIL ~ the chamber } and the substantial vacuum within
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH