Invacare IRC5P, IRC5PO2 SensO2 Oxygen Sensor Technology - Ceramic Zirconia Sensor

SECTION 2—INSTALLATION/SEQUENCE OF OPERATION
Part No 1148070 13 Perfecto2™
Theelectricalactivationofthe4‐wayValveisaccomplishedevery8to15secondsbythe
pressuresensorandP.C .Boardelectronicswhenthepressurereachesasetpointof21
p.s.i.(144.79kPa)outputflows4L/minandaboveor16p.s.i.(110.32kPa)outputflows3
L/minandbelow.Thetimebetweencyclesisdependentonaltitude,flowrateand
internalenvironmentalfactors.
AP.E .valve opensjustpriortotheshiftofthe4‐wayvalve.Thisallowshighly
concentratedoxygentoenterthejustexhaustedbedfromthetop.Thisadditional
pressureallowsthebedtostartitscycleatahigherpressure.TheP.E.valve willclosejust
aftertheshiftofthe4‐wayvalve.
Ifmainpowerislost,theBatteryFreePowerLossAlarmwillsoundashortʺBEEPʺ,with
alongpauseafter.Allunitsareequippedwithadiagnosticalarmsystemthatsignalsif
thepneumaticpressureorelectricalsystemsmalfunction.Thetroubleshootingguidein
thismanualexplainsthealarmsystemsignalsandreasons,indetail.Referto
Trou bles hoo ting onpage 16.
SensO2 Oxygen Sensor Technology - Ceramic Zirconia
Sensor
Technical Description
Theoxygenbeingproducedbytheconcentratorflowsoutoftheproducttankandinto
theflowmeter.Asmallflowofoxygenproducedbytheunitissentthroughaprecision
orificetotheoxygensensormountedontheprintedcircuitboard.
Astheoxygenentersthesensor,itpassesthroughascreenandcontactsthesensingdisk.
Electriccurrentflowingthroughametalfilmresistorheatsthediskinexcessof300°C.
Oxygenmoleculescontacttheelectrodeofthediskandpick‐upextraelectronstobecome
oxygenions.Theseoxygenionsareattractedtotheelectrodeonthebottomofthezirconia
sensingdisk.Becauseofthecrystalstructureofthezirconia,onlyoxygenionscanpass
through.Whentheoxygenionsreachthebottomelectrode,theextraelectronsare
releasedfromtheoxygenionsandoxygenmoleculesreturntotheair.Thenumberof
electronsisdirectlyrelatedtotheoxygenconcentration.TheelectronstraveltotheP.C.
boardwheretheyarecountedandtheoxygenconcentrationreadingiscalculated.
AmicroprocessorontheP.C.boardcontainssoftwarethatinterpretsthesignalbeing
receivedfromthesensor.Itcomparesthesignaltoclinicallyacceptablelimits.Signals
outsideoftheclinicallyacceptablelimitsgenerateresponsesintheformoflights,audible
indicators,and/orsystemshut‐down.
Operating Sequence
Oncethepowerswitchhasbeenturnedon(),theSensO2circuitwillwaitfiveminutes
fortheconcentratortobeginproducingclinicallyacceptableoxygenandtheoxygen
sensortostabilize.TheGREENlightwillilluminate(indicatingnormalsystemoperation)
whiletheoxygensensoriswarmingup.
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