Extech Instruments AN320 User manual

USERGUIDE
LargeVaneCFM/CMM
Anemometer/Psychrometer+CO2
ModelAN320
99 Washington Street
Melrose, MA 02176
Phone [phone]
Toll Free 1-800-517-8431
Visit us at www.TestEquipmentDepot.com

AN320-en-GB_V1.2 11/14
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Introduction
CongratulationsonyourpurchaseoftheExtechAN320VaneAirflowAnemometerPsychrometer
+CO2.ThisinstrumentmeasuresAirVelocity,AirFlow(volume),AirTemperature,Relative
Humidity,WetBulbTemperature,DewPointTemperature,andCO2(carbondioxide).Thelarge,
easy‐to‐readbacklitLCDincludesprimaryandsecondarydisplaysplusnumerousstatusindicators.
Theoptionalroundandsquareairflowconeadaptorsallowforquickairflow(volume)
measurements.Thismeterisshippedfullytestedandcalibratedand,withproperuse,willprovide
yearsofreliableservice.Pleasevisitourwebsite(www.extech.com)tocheckforthelatestversion
ofthisUserGuide,ProductUpdates,andCustomerSupport.
CAUTIONS
Improperuseofthismetercancausedamagetothemeterandpersonalinjury.Readand
understandthisusermanualbeforeoperatingthemeter.
Inspecttheconditionoftheprobeandthemeterforanydamagebeforeoperatingthe
meter.Repairorreplacedamagebeforeuse.
Iftheequipmentisusedinamannernotspecifiedbythemanufacturer,theprotection
providedbytheequipmentmaybeimpaired.
Thisdeviceshouldnotbemadeavailabletochildren.Itcontainshazardousobjectsaswell
assmallpartsthatcanbeaccidentallyswallowed.Themeter’sbatteriesandpacking
materialcanalsobedangeroustochildren.
Intheeventthatthemeteristobeunusedforanextendedperiodoftime,removethe
batteriestoprotectagainstbatteryleakage.
Expiredordamagedbatteriescanbehazardousifallowedtocomeincontactwithskin.Use
suitablehandprotectioninsuchcases.
Donotshortcircuitbatteriesorputbatteriesinfire.

AN320-en-GB_V1.2 11/14
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MeterDescription
MeterDescription(front)
1. ToplineLCDdisplayreading
2. BottomlineLCDdisplayreading
3. U/modeAVGanduparrowbutton
4. L/modeanddownarrowbutton
5. ON‐OFF(Power)andSETbutton
6. HOLD,MAX‐MIN,andleftarrow(Enter)button
7. Unitofmeasuresymbolforlowerdisplayrow
8. Unitofmeasuresymbolforupperdisplayrow
9. AirVelocityVane
MeterDescription(rear)
10. Airtemperature,humidity,andCO2sensors
11. Batterycompartment
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AN320-en-GB_V1.2 11/14
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SET
HOLD
MAX/MIN
U/mode
AVG
▲
L/mode
▼
U/mode
AVG
▲
U/mode
AVG
▲
L/mode
▼
BriefKeypadDescription

PressmomentarilytoswitchthemeterONorOFF.Pressandholdthisbuttonfor2
secondstoenterorexittheSetupmode(refertoSetupmodesectionfordetails).

oPressmomentarilytofreezethedisplayedreading(HOLDiconswitchesON);press
againmomentarilytoexittheHOLDmode(HOLDiconswitchesOFF)
oPressandholdfor2secondstodisplaytheMIN(minimum)reading;pressandhold
againtodisplaytheMAX(maximum)reading;Pressandholdathirdtimetoexit
oThisbuttonisalsousedintheAVERAGEmode(forrecordingreadingsoneatatime
orfora‘timed’recordingsession)andintheSETUPmode(forconfiguringthe
meter).PleasereviewtheAVERAGEandSETUPmodesectionsfordetails


Pressmomentarilytotogglebetweenppm(CO2),humidity,andairvelocityreadings.
Pressandholdfor2secondstoaccesstheMulti‐PointAverageandTimedAverage
modes(theAVGiconswitchesON).Detailedinstructionsforthesemodesareprovided
laterinthisguide.IntheSetupmodepresstoselectacategoryortoincreaseavalue
(refertoSetupmodelaterinthisguide)

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Presstotogglethelowerdisplaybetweenairtemperature,airvolume,wetbulb
temperature,anddewpointtemperaturereadings;AlsousedintheMulti‐Point
Average,TimedAverage,andSetupmodes;refertotheAVERAGEandSETUPmodes
sectionslaterinthisguide
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 
+WiththemeterswitchedOFF,pressandholdthesetwobuttonstodisable
AutoPowerOFF.DetailedAUTOPOWEROFF(Sleepmode)instructionsare
providedlaterinthisguide
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
++ Pressall3buttonssimultaneouslytoentertheCalibrationmode.
Calibrationinstructionsareprovidedindetaillaterinthisguide


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DisplayLayout
1. LowerDisplaydigits(airvolume,temperature,timer,ormenuparameterdisplays)
2. UpperDisplaydigits(airvelocity,humidity,CO2,ormenudisplayparameters)
3. OptionalConeorFunnelattachmenticon
4. Unitsofmeasureforductareaprogramming
5. Vaneindicator(flashesverybrieflyonpowerup)
6. DisplayHOLDicon
7. MAXmodeicon
8. MINmodeicon
9. Recordingicon
10. ElapsedTimericon
11. AVGmodeicon
12. Batterystatusicon
13. Unitofmeasureicons*

*Fulllistshown.Availableunitsofmeasureiconsvarybymodel.

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Operation
AirVelocityandAirVolumeMeasurements
1. SwitchthemeterONbypressingthePOWER buttonmomentarily.Themeterwill
countdownfrom30to0asitperformsaself‐test.PressthePOWERbuttonagaintoswitch
themeterOFF.
2. Notethatthemeterwillautomaticallyenterthesleepmodeafter20minutesofinactivity.
Todisablethisfeature:withthemeterOFF,pressandholdthePOWERandtheU/mode
buttonsfor2seconds.TheLCDwilldisplay'n'asitswitchesON.Nowthesleepmodeis
disabledandtheusermustpressthePOWERbuttonmomentarilytoswitchthemeterOFF.
3. WhenthemeterisON,theupperdisplaycanindicate
airvelocity,relativehumidity,orCO2(usetheU/mode
buttontoscroll).Thelowerdisplaydigitscanindicate
airflow,dewpointtemperature,wetbulbtemperature,
orairtemperature(usetheL/modebuttontoscroll).
4. Placethesensorintheairstream.Theairmustenter
thevanefromtherearofthemeter.TheAir
Temperature,Relativehumidity,andCO2sensorsarelocatedatthecenterofthevaneon
therearofthemeter.
5. ReadthemeasurementdataontheLCD.Airvelocityreadingsareindicatedinmetersper
second(m/s)orfeetperminute(fpm).Temperaturereadings(air,dewpointDP,orwetbulb
WBT)areindicatedin°C/°F.Airflow(volume)isindicatedinCFM(cubicfeetperminute)or
CMM(cubicmetersperminute).UsetheL/modebutton(forlowerdisplay)andtheU/mode
button(forupperdisplay)toscrollthroughthedisplayedreadingoptions.
6. TochangebetweenImperialandMetricunitsofmeasurerefertotheSETUPModesection.
7. TomeasuretheAirVolumeofaduct,firstmeasuretheduct’sarea(seetheAppendixfor
areacalculations)andthenentertheareavalueinthemeter’sSETUPmodeinin2orcm2.
Aftertheareavaluehasbeenentered,usetheL/modebuttontoscrolltotheairvolume
display(CMM/CFM)onthelowerdigits.Placethemeterinairstreamtomeasurevolume.
8. Optional:measureAirVolumewithanairflowConeorSquareadaptorbyfirstattachingone
oftheadaptorstothemeter(theoptionalconeadaptorkitincludesaroundandasquare
cone;kitpartnumberAN300‐C).Themeterwillautomaticallyrecognizethattheadaptoris
attachedtothemeterandaconeiconwillappearonthedisplay.Note:regardlessofthe
AREAsettingintheSETUPmode,themeterwilldefaulttothedimensionsofthevane
opening.Ensurethattheairflowadaptoriswellmountedandlockedbeforetaking
measurements.
LCDbacklight
PresstheU/modebuttontoswitchONtheLCDbacklight.Thebacklightwillautomaticallyswitch
OFFafterapproximately10secondstoconservebatterypower.Notethatthebacklighting
switchesONautomaticallywhenthemeterisswitchedONbytheuser.

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RelativeHumidity,WetBulb/DewPointTemperature,andCO2Readings
Sensorsarebuiltintothecenterofthevane(rearofmeter)andareusedtomeasurerelative
humidity,airtemperature,andCO2.WetBulbandDewPointtemperaturesarecalculatedbased
ontemperatureandhumidityreadings.
1. PressU/modetoscrolltoRH(%)orCO2(ppm)modes.Themeasuredrelativehumidityor
carbondioxidereadingswillbedisplayedontheupperLCDdigitsasselected.
2. UsetheL/modebuttontoscrollthroughairtemperature,dewpointtemperature,wetbulb
temperature,andairflow(volume)readings.
3. Tomeasurethehumidityusinganoffsetreferencevalue,pleaseaccesstheSetupmodeand
inputtheoffsetvalueasdescribedintheSetupmodesection.TheLCDwilldisplaythe
measuredvalueminustheoffsetvalueoncetheoffsetisprogrammedintheSetupmode.
DataHoldMode
1. PresstheHOLDbuttonfromthenormaloperatingmodetofreezethecurrentmeasurement.
2. The‘HOLD’iconwillappearatthetopoftheLCDdisplay.
3. PressHOLDagaintoreturntonormaloperation.The‘HOLD’iconwillswitchOFFandthe
meterwillreturntodisplayingreadingsinrealtime.
MAX/MINMode
TheMAX‐MINfeaturerecordsthehighest(MAX)andlowest(MIN)readingscapturedsincethe
MAX‐MINmodewasaccessed.
1. PressandholdtheMAX/MINbuttonfor2secondstobegindisplayingthelowest(minimum)
readingsencounteredsincethismodewasaccessed.The‘MIN’iconwillappearatthetopof
theLCDdisplayindicatingthatthereadingsshownarethelowestmeasured.
2. PressandholdtheMAX/MINbuttonagainfor2secondstodisplaythemaximumreadings
encountered.The‘MAX’iconwillappearontheLCD.
3. Pressandholdthisbuttonagainfor2secondstoreturntothenormalmodeofoperation
(the‘MIN’and‘MAX’iconsshouldswitchOFF).
4. WhileviewingtheMAXorMINdata,usetheL/modebuttontoswitchthedisplaysothatthe
AirVolumeMINandMAXreadingscanbeviewedalso.
5. PressandholdMAX/MINfor2secondstoreturntothenormaloperationmode.
Multi‐PointAverageMode
1. FromthenormaloperatingmodepresstheU/modebuttonfor2secondstoenterMulti‐
PointAveragemode(theAVGdisplayiconandtheassociatedblackdot•willswitchON).
2. PresstheHOLDbuttonmomentarilytorecordonereading.Theupperdisplaydigitswill
showthereading’smemorylocationnumberandthelowerdisplaywillshowthemeasured
value.PresstheHOLDbuttonagaintotakeandstoreanotherreading;thememorylocation
numberwillincrementbyoneandthecurrentreadingwillbestoredinthisnewmemory
location.
3. PressU/modemomentarilytoseethemulti‐pointmean(average)forallofthereadings
recordedduringthesession(the'•AVG'displayiconwillflashduringthisprocess).
4. PressL/modetoviewtheaveragereadingfortheotheravailableparameters.
5. PressU/modemomentarilytoreturntothenormaloperatingmode.

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TimedAverageMode
1. Fromthenormaloperatingmode,pressandholdtheU/modebuttonfor2secondstoenter
theMulti‐PointAveragemodefirstandthenpressU/modeonemoretimemomentarilyto
entertheTimedAverageMode(theAVGandtheelapsedtimer iconswillswitchON).
2. PressHOLDtobeginrecording.Theelapsedtimerstarts(asshownontheupperdisplay
digits)andtheclockiconflashesonandoff.
3. PressU/modetostoptheclockandtocalculatethetimedaverage.TheupperLCDwill
displaytheelapsedtimeandthelowerLCDwillshowtheaveragedreadings.TheLCDwill
flashthe'AVG'andtheelapsedtimericons.
4. PressL/modetoviewtheaverageforotheravailablemeasurements.
5. PressU/modetoreturntothenormaloperatingmode.

SetupMode
EnteringSetupMode
PressandholdthePOWERSETbuttonfor2secondstoenterSetupmode.Twooptionsare
available:P1.0:UnitandP2.0:AREA.
Usetheup/downbuttonstotogglebetweenP1.0UNITandP2.0AREAoptions.
P1.0:UnitSelection
1. Onceinsetupmode,attheP1.0UNITdisplay,momentarilypresstheHOLDbuttontoenter
theP1.0UNITmenu.
2. Useeitherarrowbuttontoswitchbetweenmetricandimperialunits.Theavailableunits
are:airvelocity(m/s,fpm),temperature(C,F),airvolume(CMM,CFM),andareasize(cm²,
inch²).
3. PressHOLDmomentarilytoreturntotheP1.0display.
4. PresseitherarrowbuttontomovetotheP2.0AREAoptionandfollowthestepsbelow.
P2.0:AreaSizeSelection(entersquareinchesorsquarecentimeters)
1. Insetupmode,fromtheP2.0AREAdisplay,pressHOLDtoentertheAREAsettingmenu.The
LCDwillshow‘99999’inthelowerdisplaywiththefirstdigitflashing.
2. Usetheuparrowbuttonchangetheflashingdigit(from0through9).
3. Usethedownarrowbuttontomovetothenextdigit.Usetheuparrowbuttonagainto
changetheflashingdigit.ContinueinthiswayuntilthedesiredAREAvalueisdisplayed.
4. PresstheHoldbuttonagainmomentarilytostorethevalueandtoreturntotheP2.0display.
5. PresseitherarrowbuttontomovetotheP3.0RHOFFSEToptionandfollowthestepsbelow.
P3.0:RelativeHumidity(RH)OffsetSelection
1. WheninsetupmodeP3.0pressHOLDtoentertheRHoffsetsetting.TheLCDwillshow0.0
RHintheupperdisplay.
2. PressU/modetoincreaseoffsetvalueandL/modetodecreaseoffset.
3. PresHOLDoncemoretoreturntoP3.0.
4. PressandholdthePOWERSETbuttonfor2secondstoreturntothenormaloperating
mode.

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P4.0:AltitudePressureCompensation
5. WheninsetupmodeP4.0,pressHOLDtoenterthepressurecompensationparameter.The
LCDwillshowhPA(unitofmeasure:hector‐Pascalormillibar)onthelowerlineanda
flashing4‐digitnumber(from700to1990;thedefaultis1013hPAwhichisstandard
pressure)ontheupperline.
6. PressU/modetoincreasethepressurevalueandL/modetodecreaseit.
7. PressHOLDoncemoretoreturntoP4.0.
8. PressandholdthePOWERSETbuttonfor2secondstoreturntothenormaloperating
mode.
Calibration
CAUTION:DonotcalibratethemeterinairwithanunknownCO2concentration.Doingsowill
resultinthemeterbeingcalibratedtothestandard400ppmandcouldleadtoinaccurate
results.
1. Placethemeterinacalibratedenvironment.
2. WiththemeterOFF,pressSET,HOLDandL/modesimultaneouslytoenterCO2calibration
mode.
3. Themeterwillruna30secondcountdownand'CAL'willshowinthelowerdisplay.
4. DuringcalibrationaCO2readingbetween380‐420ppmwillflashintheupperdisplay.
5. Waitforapprox.10minutesforthereadingtostopflashing.
6. Thecalibrationisnowcompleteandthemeterwillreturntothenormaloperatingmode.
7. Toabortthecalibrationatanytime,turnOFFthemeter.
8. IfthecalibrationfailsforanyreasonpleasereturnthemetertoExtechInstrumentsforan
evaluationandpossiblerepair.

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BatteryReplacement
WhenappearsontheLCD,theAAAbatteriesmustbereplaced.Thebatterycoverislocated
onthebackofthemeter.
1. Opentherearbatterycompartmentbycarefullypullingdownonthecompartment’slatch.
2. Thebatterycompartmentcovershouldbecompletelyremovedbeforeproceeding.
3. Replacethefour(4)1.5V‘AAA’batteriesensuringproperpolarity.
4. Closethebatterycompartmentbeforeattemptingtousethemeter.

Neverdisposeofusedbatteriesorrechargeablebatteriesinhouseholdwaste.
Asconsumers,usersarelegallyrequiredtotakeusedbatteriestoappropriate
collectionsites,theretailstorewherethebatterieswerepurchased,orwherever
batteriesaresold.
Disposal:Donotdisposeofthisinstrumentinhouseholdwaste.Theuseris
obligatedtotakeend‐of‐lifedevicestoadesignatedcollectionpointforthe
disposalofelectricalandelectronicequipment.

OtherBatterySafetyReminders
oNeverdisposeofbatteriesinafire.Batteriesmayexplodeorleak.
oNevermixbatterytypes.Alwaysinstallnewbatteriesofthesametype.

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Specifications
AirVelocityRangesResolutionAccuracy
m/s(meterspersec)0.2–30m/s0.01m/s±(1.5%rdg+0.3m/s)
fpm(feetperminute)40–5900fpm1fpm±(1.5%rdg+59fpm)
RelativeHumidityRangeResolutionAccuracy
RH0.1%‐99.9%RH0.1RH±3%RH(10‐90%RH)
±5%RH(<10%or>90%)
AirFlowRangesResolutionAreaRange
CMM(cubicmeters/min)0‐99999m3/min0.1upto9999.9
then1.00to99999cm2
CFM(cubicft/min)0‐99999ft3/min0.1upto9999.9
then1.00to99999in2
TemperatureRangesResolutionAccuracy
oF/oC
AirandWetBulb:
‐20to60oC(‐4to140oF)
DewPoint:
‐5to60oC(23to140oF)
0.1oC(oF)
±0.6°C(‐20to50°C)
±1.2°C(51to60°C)
±1.1°F(‐5to122°F)
±2.2°F(123to140°F)
CO2
RangeResolutionAccuracy
PPM(partspermillion)
0–9999ppm
(readingsover5000are
notspecified)
1ppm±(30ppm+5%ofrdg)
from0to5000ppm

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CircuitCustomLSImicroprocessor
DisplayDualfunction13mm(0.5")4‐digitLCD
Samplingrate1readingpersecondapprox.
Airvelocity/flowsensor Conventionalangledvanearmswithlow‐frictionballbearing
TemperatureSensorNTC‐typeprecisionthermistors
CO2Sensor NDIRCO2sensor
AutomaticPoweroffAutoshutoffafter20minutestopreservebatterylife(sleepmode)
OperatingTemperature0°Cto50°C(32°Fto122°F)
StorageTemperature‐10°Cto50°C(14to122oF)
OperatingHumidity<80%RH
StorageHumidity <90%RH
OperatingAltitude2000m(7000ft.)maximum
BatteryPowerFour(4)‘AAA’1.5Vbatteries
BatteryLife>40hours
Batteryconsumption8.3mADC(approx.)
Weight725g(1.6lbs.)includingbatteryandprobe
DimensionsMaininstrument:269x106x51mm(10.6x4.2x2”)
Vaneinnerdiameter:100mm/3.94inches
OptionalAirFlowAdaptors:
Round:210mm(8.3”)Diameter
Square:346x346mm(13.6x13.6”)

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ErrorMessages
Errorcodesandsolutions

AirTemperature
E02:Temperaturereadingislowerthanthelowrangelimit.Placethemeterinroom
temperaturefor30minutes.IfE02continues,sendtheunittoExtechforrepair.
E03:Temperatureexceedsthehighrangelimit.Placethemeterinroomtemperaturefor30
minutes.IfE03continuestoappear,sendtheunittoExtechforrepair.
E31:TheA‐to‐Dconverterrequiresreplacing.SendthemetertoExtechInstrumentsforrepair.

RelativeHumidity(RH)
E04:Temperatureerrorcorruptedthehumidityreading.Checkthetemperatureerrorsolution
section.
E11:RHcalibrationerror.SendtoExtechInstrumentsforrepair.
E33:RHmeasurementcircuiterror.SendtoExtechInstrumentsforrepair.

DewPoint(DP)andWetBulb(WBT)Temperature
E04:TemperatureorRHerror.ChecktemperatureorRHerrorsolutions.

Airvelocity
E03:Velocityexceedsthehighrangelimit.Testthemeterusinganairvelocitythatisknown
tobewithinthespecifiedrangelimits.SendtheunittoExtechforrepairiftheE03error
messagepersists.

Airvolume
E03:Readingexceedsthemeter’sdisplaylimit.CheckthattheAREAsettingiscorrectinthe
SetupMode.
E04:Airvelocityerror.ReturnmetertoExtechforrepair.

CO2
E01/E33:VoltagetooloworCO2moduleerror.Checkifthelowbatteryiconisdisplayedon
theLCD,ifyes,replacewithnewbatteries.Tryarecalibration,orsendtheunittoExtechfor
repairiftheproblempersists.

OtherErrors
E32:MemoryICerror.Rebootthemeterandcheckitagain;sendittoExtechInstrumentsfor
repairiftheerrormessagepersists.
Nodisplay
1. Checkthatthebatteriesaremakinggoodcontactandarealignedforcorrectpolarity.
2. Replacebatteries.
DisplayswitchesOFFautomatically
Thissymptomcouldbethenormal‘SleepMode’whichswitchesthemeterOFFafter20
minutesofin‐activity.Ifthisisnotthe‘SleepMode’,checkwhetherthelowbatteryindicator
appearsbeforetheLCDattemptstoswitchON;ifyes,replacethebatteries.


AN320-en-GB_V1.2 11/14
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Appendix:UsefulEquationsandConversions
Areaequationforrectangularorsquareducts
Areaequationforcircularducts
Cubicequations
NOTE:Measurementsmadeininchesorcentimetersmustbeconvertedtofeetormetersbeforeusingtheseformulae.
UnitofMeasureConversionTable
m/sft/minknotskm/hMPH
1m/s1196.871.9443.62.24
1ft/min0.0050810.009870.018290.01138
1knot0.5144101.2711.85191.1523
1km/h0.277854.690.5410.6222
1MPH0.446487.890.86791.60711
Width(W)
Height(H)Area(A)=Width(W)xHeight(H)
CFM(ft3/min)=AirVelocity(ft/min)xArea(ft2)
CMM(m3/min)=AirVelocity(m/sec)xArea(m2)x60
RadiusArea(A)=pi xr2
Wherepi=3.14andr2=radiusxradius
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