ZeroCalibrationresetsthebaselinelevelreadingtozero.Ifthetargetgasissuspectedtobeoccasionallypresent,itisbest
toalsouseazerogascylinderduringthezerocalibration.Ifthetargetgasisnotpresentintheatmosphere,anadditional
calibrationcylinderisnotrequired.
The"Calibrate"optioninvolvesfirstapplyingazerogasfollowedbythespangas.Thespangasisaknownconcentrationof
gaswhichadjuststheaccuracyandprecisionofthetransmittertotheknownvalue;thisisreferredtoasthe“SpanValue.
SeeFigure41.
Figure 41 Calibration Curve
TheSensorSpanValueinthedevicemenushouldbethesameastheconcentrationlistedonthecalibrationgascylinder;
unlessanLELsimulantgasisbeingused.
TheXIRPlussensorcanbecalibratedtoawidevarietyofgascompoundsusingeither0.1%Propane,0.6%Propane,or
2.5%MethaneandMSA'sgastable.SeeTable21foracompletelistofgascompoundsandcorrespondingtablesand
spanvalues.
5.5 HowtoZeroCalibrateXCellSensors
NOTICE
Ifapasswordisenabled,youwillnotbeabletoproceedwiththecalibrationwithoutthepassword.
Toabort,presseitherbuttononthetouchscreenormobileapplicationatanytimeduringthezerocalibration.
Intheeventthatacalibrationcannotbecompleted,theusercanacknowledgetheFAILbyplacingonefinger
overeachoftheEZtouchbuttonsandholdingfor1secondbeforereleasing.Theunitwillreverttothesettingsof
thelastsuccessfulcalibration.
WARNING!
Theregulatorusedwiththezerogascylindershouldnotbethesameastheregulatorusedforthespangas.Thespangas
regulatorcanbecontaminatedwiththetargetgasovertime,andthusraisethedetectionbaselineandmakethesensorless
sensitivetothetargetgas.
64 Ultima X5000 Gas Monitor US
5 Calibration