it is to be understood that the accompanying drawings are schematic only and focus upon the salient elements of the apparatus taught herein . elements of the apparatus and system which are not necessary from the understanding of the teachings herein have been omitted for the sake of clarity . it is also to be understood that the drawings are not intended to show any of the components to scale . referring first to fig1 , this shows in schematic form the general arrangement for zone or room isolation . the arrangement separates two rooms or zones 10 , 12 from one another , which in this example are delineated by a dividing wall 14 having an opening 16 therein . disposed across the dividing wall 14 within the opening 16 is a sterilization unit 18 , typically an autoclave , in this example a steam sterilizer . the sterilization unit 18 includes a sterilization chamber 20 and opposing doors 22 , 24 for access into the chamber 20 and between the rooms or zones 10 , 12 . a sealing assembly 26 is disposed around the exterior of the sterilization unit 18 to seal any space or gap between the opening 16 and the sterilization unit 18 . access between the two rooms or zones 10 , 12 can be achieved solely through the sterilization chamber 20 , thereby maintaining one of the zones under sterile conditions or containing securely contaminants within one of the zones . an example of seal assembly for the structure of fig1 can be seen in fig2 . shown schematically in this drawing is a sterilization - side flange 30 , which may be formed integrally with the sterilization unit 18 and which extends around the outside perimeter of the unit 18 , both at its sides and also along the top and bottom walls of the unit 18 . attached to the walls 14 , and equally to a ceiling or wall structure above the sterilization unit 18 and along the floor , there this a frame element 32 . connected across the flange 30 and frame element 32 is a sealing unit 34 , coupled in this example by a series of bolts 36 disposed at spaced intervals along the sealing unit 34 and fitting into appropriate holes in the flange 30 and frame 32 . all gaps between the walls and the sterilization unit 18 and the adjacent structure or structures , in this example walls 14 , are typically sealed in this manner . the intention of this arrangement , as the person skilled in the art will know , is to ensure that the only path from zone 10 to zone 12 and vice versa is through the sterilization unit 18 . a variety of methods are known for testing the integrity of a seal of the type shown in fig2 . one method commonly used is to pressurise one room 10 relative to the other room 12 and then to check for leaks using sensors in room 10 . however , such testing has shortcomings . one occurs because the pressurisation of , for example , room 10 can only be carried out once all penetrations and apertures in the room 10 have been closed , usually sometime after installation of the sterilization unit 18 . furthermore , such testing is a “ one time ” event , carried out during the construction of the building . after commissioning , leakages can result in the escape of pathogens from one room when used for containment or contamination of a sterile room . in particular , the problem with the arrangement shown in fig2 is that there is no way of determining whether the sealing element 34 provides a secure seal between the two rooms or zones 10 , 12 . any leakage from the sealing element 34 cannot generally be detected . referring now to fig3 , this shows in schematic form a preferred embodiment of the present invention . disposed between the sterilization unit 18 and the wall 14 is a seal assembly 40 which includes a sterilizer - side flange 42 extending along the sides of the sterilization unit 18 which are disposed in the opening 16 in wall 14 . the seal assembly 14 also includes a wall frame element 44 , which is preferably a metal fabrication installed within the wall aperture where the sterilizer unit 18 is to be located . the metal frame 44 is sealed to the adjacent walls , ceiling and floor , advantageously during building construction . the connection to the walls , floor and ceiling is airtight . the embodiment of fig3 includes a double seal assembly 50 , which includes first and second seal strips or gaskets 52 , 54 disposed either side of the flange 42 and of a flange 58 of the wall frame 44 , leaving a gap or seal chamber 60 between the first and second gaskets 52 , 54 . the gaskets 52 , 54 are fixed to the flange 42 and wall frame 44 by any suitable means , in this example by a series of bolts 56 . any other coupling or bonding arrangement may be used in place of the bolts 56 . the gaskets 52 , 54 may be made of a rubberised material , for instance ethylenepropylenediene monomer ( m - class ) rubber ( epdm ), or any other suitable sealing material . in another embodiment the gaskets could be made of sheet metal , for instance , with rubberised seals disposed around their peripheries . the gaskets could each be made of the same material but it is not excluded that they may be made of different materials . coupled to the double seal assembly 50 , in this example through an opening or port in one of the gaskets 54 , is a sensor probe 62 , preferably a pressure sensor . when the double seal arrangement 50 is assembled as shown , with the gaskets 52 , 54 fitted and sealed to the flange 42 and wall frame 44 as shown , the seal chamber 60 between the gaskets 52 , 54 can be pressurised with a suitable fluid ( air may be used as one example ). pressurisation could usefully be by pumping fluid under pressure through the same aperture or port into which the pressure sensor 62 is then fitted , although this could be by any other suitable means or inlet port . as long as the gaskets 52 , 54 provide a proper seal , there should be no drop in pressure of fluid held in the seal chamber 60 . on the other hand , where there is leakage through or around either of the gaskets 52 , 54 , pressure in the seal chamber 60 will drop , which will be detected by the pressure sensor 62 . in practice , the sensor probe 62 will be coupled to a suitable control or warning unit ( not shown ) which will generate a warning signal indicative of seal failure . a warning unit could be coupled directly to the assembly or could be a remote monitoring unit , in which case a communication link , wired or wireless , may be provided . it will be appreciated that the assembly shown can determine the quality of seal provided by the double seal assembly 50 even before completion of construction of the building , that is before any other apertures or penetrations in the wall 14 or elsewhere in the room 10 / 12 have been sealed . furthermore , provision of dual seal gaskets 54 , 56 provides added security in that detection of a leak is likely to occur when just one of the two gaskets 52 , 54 is defective , thereby without loss of sterilization or containment in the associated room 10 / 12 . it is to be understood that the seal chamber 60 may be provided with other detectable fluids , one example being a pure gas , with an appropriate gas sensor able to detect the purity ( concentration ) of that gas within the seal chamber 60 . another example provides a coloured fluid . in practice the seal chamber 60 may be filled with any suitable fluid which provides a detectable parameter . in other embodiments the seal chamber 60 may be held under vacuum , with the pressure sensor 62 measuring for loss of vacuum , that is pressure rise , over time . referring now to fig4 to 9 , these show features of a practical embodiment of sterilization unit and double seal assembly as taught herein . fig4 shows a front elevation view of a sterilization unit 18 having provided therearound a double seal assembly 50 and in particular which extends around the entirety of the perimeter of the sterilization unit 18 , that is at each side , at its top and at its bottom . the double seal assembly 50 extends across the side walls , the ceiling or ceiling wall and to the floor surrounding the sterilization unit 18 . fig5 shows a side elevation view of the assembly of fig4 , whereas fig6 shows a plan view thereof . the seal chamber 60 is preferably continuous around the whole of the sterilization unit 18 , as will be apparent from the view of fig4 . referring now to fig7 , this shows a cross - sectional view along lines a - a of the double seal assembly 50 of fig4 . as can be seen , the structure is as depicted schematically in fig3 and preferably also includes : an inner bolt bar 70 , an inner compression bar 72 , an outer bolt bar 74 and an outer compression bar 76 . these bars 70 - 76 ensure adequate compression of the seal gaskets 52 , 54 when the bolts 56 are tightened . fig8 shows a cross - sectional view of the double seal assembly 50 which extends along the bottom of the sterilization unit 18 , taken along lines b - b . this is the same as the assembly 50 on the other sides of the sterilization unit 18 save for , in this example , the fact that the spacing between the flange 42 of the sterilization unit 18 and the frame element 44 is less ( to provide a lower step into the sterilization chamber 20 ). referring now to fig9 , this shows a cross - sectional view of the double seal assembly 50 across line c - c of fig4 , which is the same as the remainder of the double seal assembly 50 , save for the provision of a port 80 within the seal gasket 54 which can be used , in this example , both for filing the space 60 with fluid ( or vacuuming the space 50 in the case where this is to be held under vacuum ) and for holding a suitable sensor probe , such as the temperature probe 62 . it will be apparent that although in the preferred embodiment the seal chamber 60 extends around the entirety of the perimeter of the sterilization unit 18 , such that there is a single seal chamber to monitor , in other embodiments there may be provided a plurality of seal chambers around the perimeter of the sterilization unit 18 , each having its own sensor probe and its own port coupling 80 . a single seal chamber is preferred as this is continuous around the entirety of the sterilization chamber 18 and does not leave any zones which cannot be monitored . all optional and preferred features and modifications of the described embodiments and dependent claims are usable in all aspects of the invention taught herein . furthermore , the individual features of the dependent claims , as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another . the disclosure in the abstract accompanying this application is incorporated herein by reference .
a seal arrangement for sealing a space between a sterilization unit and adjacent walls in order to separate first and second rooms has a double seal gasket arrangement with a seal chamber there within . the seal chamber may be pressurized with a fluid and then the pressure within the seal chamber monitored by a pressure sensor . the double seal assembly provides an arrangement which can give an indication of the quality of the seal in order to detect any leakage and a more secure seal around the sterilization unit and as a result secure separation between a sterile or contaminated room and a general hospital area .