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documentno.:X1-25_4.pdf
external exhaustfan
processor
exhaustport
(dis100mm)
flexible hoseorfixedpiping system
(dia100mm)
airflow
positionformeasurement
Asmentionedearlier,toprotecttheprocessoraswellasanyequipment thatmaybedirectlyinterfaced
toorwiththeprocessor,theprocessormustbe connectedtoanexternalexhaustsystem.
(failuretocorrectlyventilatethe processoranddryerexhaustwillresultin corrosion
within the processorandinterfacedequipment-inaddition,theprobabilityofprocessor-related film
artifactsis increased).Theexhaustsystemprovidedattheinstallationsiteshouldcomplyasfollows:-
1) Thedisposaloftheeffluentairmustcomplywithalllocalenvironmentalsafetlycodesandregulations.
2) Thefollowing calculationshouldbe used todeterminethe fficiencyofthe systemprovidedandthatthe
thecorrectamountofend tobeconnectedto theprocessor.Topreventventurieffectattheductopening,
allmeasurementsshouldbemadeatapoint30cmfromthe openendoftheductto beattached tothe
processor.
3) MeasurementcanbemadetypicallyusingaDwyerAirMeter(seetheimage below)Ifsucha device is
notavailable,contactyourlocalrepresentiveforfurtherinformations.
4) If solidmetalorrigidplasticductingis attachedtotheprocessorin a mannerwhich wouldprevent easy
removal,asmallholemaybecreatedatapoint approximately30 cmfromthe processorventilation
port.The„L“shapedmetaltubeprovided withtheDwyerAirMetercan thenbeinserted throughthe
opening. When measuringnegative air,the tubetipopening shouldbe pointedinthedirectionof airflow
awayfromthe processor.Theprocessormustbede-energizedwhenmakingairmeasurements.Theair
metershouldbeheldintheverticalpositiontoassurethe greatestaccuracy.Themetertubing mustnotbe
kinked.
Itis mostimportant that negativeairflow inthe processorexhaustductremains
constantwhentheprocessoris intherun,standby,and shut-downmodes.
Whenprocessorsareinstalledindarkroomwall openings,itis mostimportant
thatdarkroomairpressureexceedstheairpressureofthearea surrounding
thedarkroomThis is intendedtopreventaircascadingthroughtheprocessor
intothe darkroomarea.Properbalancingof dark/lightedroomairinaddition
tocorrectdryerventingwillnotonlymaximizecontainmentof chemicalfumes
andvaporswithintheprocessoranditsdryerexhaustingsystem,butthe
incidenceof filmartifactsoccurringintheout-of-solutiontransport roller
sectionswill begreatlyreduced.Topreventpositiveairflowfromflowing back
intothe processorfromthebuildingexhaustthereshouldbean airgapnot
exceedingmorethan5.08cm(2.0in.)between theprocessorexhausthose
andthebuildingexhaust.thiswillbenefitthesiteintwo ways:
1.The gapcanbeadjustedtoprovidecorrectnegativeflow incaseswhere
buildingexhaustexceedsrequirements.
2.Preventpositiveflow returningtotheprocessor.
NeagtiveStaticPressure-Waterhead
at100mmtubesize: min0,76mm-max.1.02mm
NOTE:Iftheventilation tubing is connectetto house-internal exhaust
system,anair-gabof 5cm(2inch) has to beprovidedaccordinghly.
