Extech Instruments ExStik DO600 User Manual page 4

Calibration
1. Calibrationshouldbeperformedonadailybasis.
2. TurnthemeterON
3. PressandholdtheMODE/HOLDbuttonuntil%isdisplayedontheLCD.
4. Ifthemeterhasnotbeenusedforseven(7)daysorlonger,allowtheelectrodetofully
polarize.Thismaytake2‐3minutes.
5. Placetheelectrodecapontotheelectrode.Thespongecontainedinthecapshouldbeonly
moistened(notsoaked)with(distilledwater)orcleantapwater.Besurethattheelectrode
membraneiscleananddryorthecalibrationwillbeincorrect.Thereneedstobeanairgap
betweenthemembraneandthesponge.Nevertouchthemembrane,asskinoilwillaffect
theelectroderesponse.
6. WaituntilthereadingstabilizesthenpressandholdtheCAL/RECALLbuttonuntilCALis
showninthelowerdisplay.Thereadingswillblink"101.7"and"SA"willappear.
7. Whenthecalibrationiscomplete"End"willappearandthenthemeterwillreturntothe
normalmeasurementmode.Turnoffthemeter.
Note:The"SA"willnotappearifthecalibrationfails.

Optional'zerooxygen'calibration(improvesmeasurementaccuracyforveryloworveryhighDO
measurements):
Placetheelectrodeinazerooxygencalibrationsolution,suchas5%sodiumsulfite,waitfor
stabilityandpresstheCAL/RECALLbuttonuntilCALisshownintheinthelowerdisplay.Stabilityin
azerosolutionmaytakemanyminutes,dependingonelectrodehistory.
Note:SodiumSulfitecanbecomedepositedontheelectrodeandonthe"coined"surfaceofthe
electroderetainingcollar.ThepresenceoftheSodiumSulfitewillnegativelyaffectfutureDO
measurementsuntilsuchatimewhereALLofitisremovedfromtheelectrode.

OptionalElectronicZerocalibration.
IftheDO600isnotmakingstablemeasurementsoryouarereplacingtheelectrodewithanew
assembly,performthisZerocalibration.

Turnoffthemeter,removetheelectrodebyunscrewingtheretainingringandpulloffthe
electrode.
TurnonthemeterandwaitfortheSelfcalibrationtocomplete.
SettheModeto%.
PressandHoldtheCALbuttonuntilCALappearsonthedisplay.Whenthecalcyclecompletes,the
displayshouldread0.0%.
Turnoffthemeter.
Re‐attachtheelectrode.PerformtheelectrodecapcalibrationfromStep5.
4 DO600-en-GB_V7.4 12/16