Volume 8 No 3 Jun 1957.pdf - Lakes Gliding Club

during the inspiratory phase of the breathingcycle, and extensive tests have shown itto be an improved method of supplyingoxygen at high altitudes, inasmuch that100% oxygen -is assured as long' as theface-to-mask seal is airtight.A simple valve fitted to the mask permitsexhaled air to be blown off to atmosphere.During inspiration this valve closes and noair is admitted to the mask.The demand regulator is a meteringsystem which controls the flow ofoxygen tothe mask. Basically it consists of a roundbox across which is stretched a thin rubberdiaphragm. Attached to the diaphragm is alinkage to the valve which opens or closesthe port -connected to the oxygen cylinder.When the mask is attached to the regulatorvia a hose connection and the wearer inhales,a sligllt negative pressure sucks in thediaphragm which in turn operates thelinkage and opens the valve. In practice, ofcourse, the victim is protected fr,orn the full1,800 p.s.i. cylinder pressUT,? by.two reducingstages, and the oxyg~n IS dehveretl tohim at ambient pressure."ceiling for this type 0/equipment • .."Oxygen regulators of t~e. dilut~f ~m~n~type incorporate an additional aIT mIxstage which conserves the oxygen supplyby nri,ung it with air at altitudes belowabout 31 000 ft. The diluter mechanismwhich ~es the air and oxygen consists ofabellows-.control1ed lever which in turncontrols the air and oxygen ports. As thealtitude increases, the oxygen valve slowlyopens and the air.valve ~Iowly.closes. ~usthe air/oxygen mixture IS ~aned a~cord:mgto altitude in al:COrdance with phYSlologJcalrequirements. Experience suggests that thediluter demand system is -good up to about40,000 ft.For the hardierspirit a pressure breathingdiluter demand Qxygen regulator, in conjunctionwith the appropriate mask, can ~used up to about 44,000 ft" but above thisheight the usual m~ aids. to. highaltitude daustrophobla becOme InevItable.-121-_~,-illt ....."high altitude claustrophobia . .."What does the diluter demand systemhave to offer? At a weight comparable withthe continuous flow system it PTovides:-I. Maximum economy, as the oxygensupply is automatically adjusted topersonal needs and altitude.2. Extreme simplicity: oxygen is permanentlyavailable at the regulator;to obtain delivery it is only necessaryto put on the mask and breathe in.3. Greater safety-particularly at heightsin excess of 25,000 ft.British ~gen _Aero Equipment ~jJ1shortly be marketing a gliderset which'consists ofa 4OO-litre cylinder together withthe Aero A·I2A dilut,er demand oxygenregulator ,and a mask and hose assell.lbly,and it is expected that one set at least WIll beseen at the British National Championships.The A·14 pressure breathing regulator,together with a suitable mask, will also beavailable as an alternative.WESTERN•AIRWAYSExtensive spdres stocks heldindudinil :FABRIC DOPE and PAINrPLYWOOD A.G.S. PARTS........... "Iw~WESTON AIRPORTWESTON-SUPER-MARE_. WISTON-SUPIR-MARI 27'00