room that the seal can be inflated and the door locked the second proximity sensor 80 is positioned in a sleeve 82 passing through the frame 16 that sensor is so positioned that the end 84 of sensor 80 will lie opposite an exposed section 86 of the side of door 12 therefore when the door 12 is in the closed position the proximity sensor 80 will activate a circuit leading to a indicator light 81 to indicate that the door is closed and that the sealing and locking mechanism can be activated the door 12 may also be provided with a viewing port 88 because of the strict requirement that no fasteners may penetrate the door the glazing 90 for port 88 is set into a retaining ring 92 which is secured to the door 12 by a continuous air tight weld 94 the glazing 90 is retained within the ring 92 by a glazing ring 96 secured by screws 98 the glazing 90 is sealed with silicone as illustrated at 100 in order to test the sealing integrity of the complete door assembly 10 including not only the inflatable seal 36 but also all other aspects of the assembly a test panel 102 is preferably provided the panel 102 is adapted to be secured within the door frame 16 to define a closed space 103 between panel 102 and door 12 the panel 102 is preferably.