Extech Instruments LT40 Manuale utente

USERGUIDE

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WhiteLEDLightMeter

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ModelLT40

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LT40-EU-EN v1.3 9/13

Introduction

CongratulationsonyourpurchaseoftheExtechLT40LEDLightMeterthatmeasureslightfrom

whiteLEDlight,fluorescent,metalhalide,high‐pressuresodiumandincandescentsources.The

LT40canmeasurelightupto400,000Lux(40,000Fc).TheLT40offersanoverloadindication,low

batteryindication,Datahold,maximum/average/minimumhold(MAX/MIN),Zeroadjustment,

autopoweroffwithdisablefunction,andautorangingfeatures.Thisinstrument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.

Features

OverloadIndication:LCDscreenwillshow“OL”attheupperleft‐handcorner.

LowbatteryIndication””.

DisplayUpdateRate:2.5timespersecond.

SpectralresponsenearCIEluminousspectralefficiencyratings.

CosineAnglecorrected.

ConformstoJISC1609:1993andCNS5119generalclassASpecifications.

MeasuresLEDwhitelightandallvisiblelight.

MeasurestheintensityofilluminationinLuxorfoot‐candles.

Applicationsinclude:Warehouses,factories,officebuildings,restaurants,schools,library,

hospitals,photo/video,parkinggarages,museums,artgalleries,stadiums,building

security.

Dataholdfreezesdisplayedreading.

Maximum/Average/MinimumMemoryHold

Zeroadjustment.

Autopoweroffwithdisablefunction.

Autorange.

Safety

Donotoperatethemeterinenvironmentswherethefollowingarepresent:explosivegases

(ormaterials),combustiblegases(ormaterials),steam,ordust.

Pleasereplacethebatteryimmediatelywhenthesymbol“ ”appearsontheLCD.

Donottouchthemeter’scircuitboardforanyreasonasstaticelectricityorcontamination

coulddamagethesensitivecomponents.

ForIndooruseonly.Thisinstrumentwasdesignedforpollutiondegree2.

OperationAltitude:Upto2000m(7000’).

LT40-EU-EN v1.3 9/13

MeterDescription

1. Photodetector(removeprotectivecovertoexposesensor)

2. Display(LCD)

3. Controlpush‐buttons

4. PowerButton:ON/OFF

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Batterycompartmentandtripodmountarelocatedon

rearofinstrument

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Push‐ButtonDescription

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1. Lux/Fcunitsselector

2. CalibrationandZERObutton

3. Maximum/Average/Minimummemorybutton

4. Dataholdbutton

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LT40-EU-EN v1.3 9/13

Operation

PowerON‐OFF 

PressandholdthePowerbuttonforatleast2secondsandthenreleasetopowerthemeter.To

powerthemeterOFF,momentarilypressthePowerbutton.

TakingMeasurements

1. SwitchthemeterONandremovethesensor’sprotectivecovertoexposethelightsensor

dome.ThedisplayshouldswitchON,ifnotcheckthatbatteriesareinstalledandfresh.

2. Themetermeasurestheintensityofthelight(illuminance)thatstrikesthesensordomein

footcandlesandluxunits(1fc=10.76lux),displayingthismeasuredvalueonitsLCD.

3. Positionthemeterandlightsourcesothatthelightstrikesthesensordomestraighton

(perpendicular)withaslittleanangleaspossible.

4. Themeter’sdisplaycanshowavalueupto3999.However,forreadingsthatrepresent

measurementshigherthanthis,themeterusesx10feature(right‐mostdecimalpoint

flashing).Forexample,torepresentameasurementof39,999themeterwilldisplay3999

withtheright‐mostdigitflashing.

AutoPowerOFF

Tosavebatterylife,themeterpowersdownautomaticallyafterapproximately12minutesof

inactivity.

Enable/DisableAutoPowerOff

WhilethemeterisON,pressandholdthePowerbuttonforatleast2seconds(andthenrelease)

todisabletheAutoPowerOFFutility;theClocksymbolwillswitchOFF.ToenabletheAuto

PowerOFFutility,repeatthisprocess.

LUX/FCButton

PresstheLUX/FCbuttontotogglebetweenLuxandFC(foot‐candles)measurementunits.

LT40-EU-EN v1.3 9/13

MAX/MINButton

Themetercanrecordthemaximum,minimum,andaveragereadingsasdescribedbelow:

1. Momentarilypressthe“MAX/MIN”buttonandthemeterwillbegintotrackthe

maximum/average/minimummeasurements;the“MAX”iconwilldisplayatthetopofthe

LCDwindowindicatingthatthemeterisnowshowingthemaximumreading.Thereading

willnotchangeuntilahigherreadingisregistered.

2. Pressthe“MAX/MIN”buttonagaintoswitchfrom“MAX”to“AVG”,wherethemeterwill

showtheaveragemeasurementvalue.The“AVG”iconwillbedisplayedabovethedisplayed

value.

3. Pressthe“MAX/MIN”buttonagaintochangethemodefrom“AVG”to“MIN”,wherethe

meterwillshowtheminimumvaluemeasured.The“MIN”iconwillbedisplayed.

4. Pressthe“MAX/MIN”buttonagaintoswitchfrom“MIN”backto“MAX”.

5. Toexitthismode,holdthe“MAX/MIN”buttonforatleast2seconds.TheMAX/AVG/MIN

iconsshouldallbeswitchedOFFwhentheunitreturnstothenormaloperatingmode.

Data‘Hold’Button

PresstheHOLDbuttontofreezesthecurrentreadingontheLCD.PresstheHOLDbuttonagain

toreleasethereading.

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CALIBRATIONandZEROButtons

1000LUXCalibration

1. Preparea2856oK/1000Luxlightsourceandfacethemeter’ssensorperpendicularly

towardthelightsource.

2. Simultaneouslypressandholdboththe“CAL/ZERO”buttonandthepowerbuttonforat

least2seconds.

3. Releasethebuttonswhen“CAL”isdisplayedontheLCDscreen.

4. Pressandholdthe“CAL”buttonfor2moreseconds,andtheLT40willpowerdown.

5. Themeterisnowcalibrated.

ZEROCalibration

1. Ensurethattheprotectivecoverisattachedtothelightsensor.

2. PowerthemeterandtheLCDshoulddisplay‘0’.

3. Momenarilypressthe“ZERO”buttonforthezeroadjustmentandtheCALiconwill

switchON.

4. TheCALiconwillswitchOFFwhenthecalibrationhasbeencompleted.

5. IftheprotectivecapisnotcoveringthesensorwhentheZEOcalibrationisstartedthe

LCDdisplaywillread“CAP”.Inthiscase,pleasecoverthesensorwiththecapandrestart

thisprocedure.

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LT40-EU-EN v1.3 9/13

MeasurementConsiderationsandUserTips

Formaximumaccuracyallowthelightbeingmeasuredtofalldirectlyonthesensoras

perpendicularaspossiblewithaminimalangleofincidence.

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Whenthemeterisnotinusepleasekeeptheprotectivecapinplaceoverthelightsensor.

Thiswillprolongthelifeofthesensor.

Whenthemeteristobestoredforlongperiods,pleaseremovethebatteriesandstorethem

separately.Batteriescanleakandcausedamagetothemeter’scomponents.

Avoidareasofhightemperatureandhumiditywhenusingthisinstrument.

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BatteryReplacementandMaintenance

Cleaningandstorage

1. Thewhiteplasticsensordomeshouldbecleanedwithadampclothwhennecessary.Use

onlyamildsoapifneeded.Donotusesolvents,abrasives,orharshdetergentstocleanthe

dome.

2. Storethemeterinanareawithmoderatetemperatureandrelativehumidity.

BatteryReplacement

Whenthebatterypowerdecreasestoacriticallevel,thelowbatterysymbol“”willappearon

theLCD.Replacethe2x1.5VAAAbatterieslocatedintherearbatterycompartment.The

batterycompartmentslideseasilydownwardforremoval.Ensurethatthecompartmentcoveris

securelyfastenedbeforeusingthemeter.

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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.

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BatterySafetyReminders

oPleasedisposeofbatteriesresponsibly;observelocal,state,nationalregulations.

oNeverdisposeofbatteriesinafire;batteriesmayexplodeorleak.

oNevermixbatterytypes;installnewbatteriesofthesametype.

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LT40-EU-EN v1.3 9/13

Specifications

Display4‐digitLCD(maximumdisplay:3999)withlowbatteryicon,

measurementoverload,andotherfunctionindicators

Sensor(detector)Siliconphotodiodewithspectralresponsefilterandcosine

correction

RangesandResolutionLux:399.9,3999,*39999,*399999

Foot‐candles:39.99,399.9,3999,*39999

*Readingsabove3999useax10orx100multiplier

(1Fc=10.76Lux)

Auto‐rangeThemeterautomaticallyrangesthedisplay

Accuracy±(3%ofreading+3digits)upto500Lux

±(3%)above500Lux

Calibratedtostandardincandescentlamp2856oKatan

ambienttemperatureof23oC

±8%forothervisiblelightsources

30±2%

60±6%

Angledeviationfromcosine

characteristics

80±25%

GeneralSpecifications

Samplingrate2.5timespersecond(digitaldisplay)

PhotodetectorSiliconphoto‐diodewithspectralresponsefilterandcosine

correction

OperatingconditionsTemperature:5to40oC(41to104oF);Humidity:<80%RH

StorageconditionsTemperature:‐10to60oC(14to140oF);Humidity:<70%RH

Lowbatteryindication“ ”appearsontheLCDwhenbatteryvoltagefallscriticallylow

LEDType WhiteLEDlightcanbeaccuratelymeasured

Powersupply2x1.5V‘AAA’batteries

BatterylifeApproximately200hours

AutoPowerOFFMeterswitchesOFFafter12minutesofinactivity

Dimensions133x48x23mm(5.2x1.9x1”)

Weight250g.(8.8oz.)includingbatteries

LT40-EU-EN v1.3 9/13

Appendices

TypicalLightLevels(1Fc=10.76Lux)

LuxFoot

Candles

LuxFoot

Candles



 Factories Home

20‐752‐7EmergencyStairs,Warehouse 100‐15010‐15Washing

75‐1507‐15Exit/EntrancePassages150‐20015‐20Recreational

Activities

150‐30015‐30PackingWork200‐30020‐30DrawingRoom,

Table

300‐75030‐75VisualWork:ProductionLine300‐50030‐50Makeup

750‐1,50075‐150Typesetting:InspectionWork500‐1,50050‐150Reading,Study

1,500‐3,000150‐300ElectronicAssembly,Drafting1,000‐2,000100‐200Sewing

 OfficeRestaurant

75‐1007‐10IndoorEmergencyStairs75‐1507‐15CorridorStairs

100‐20010‐20CorridorStairs150‐30015‐30Entrance,

WashRoom

200‐75020‐75Conference,

ReceptionRoom

300‐75030‐75CookingRoom,

DiningTable

750‐1,50075‐150ClericalWork750‐1,50075‐150ShowWindow

1,500‐2,000150‐2000Typing,Drafting

 StoreHospital

75‐1507‐15Indoors30‐753‐7EmergencyStairs

150‐20015‐20Corridor/Stairs75‐1007‐10Stairs

200‐30020‐30Reception100‐15010‐15SickRoom,

Warehouse

300‐50030‐50DisplayStand150‐20015‐20WaitingRoom

500‐75050‐75Elevator200‐75020‐75MedicalExamRoom

750‐1,50075‐150ShowWindow,

PackingTable

750‐1,50075‐150OperatingRoom

1,500‐3,000150‐300Storefront,ShowWindow5,000‐10,000 500‐1000EyeInspection



SpectralSensitivity

Peaksensitivitywavelength:550nm;

Deviationfromcomparativeluminosity

standard:JISstandardC1609‐1993.



Allrightsreservedincludingtherightofreproductioninwholeorinpartinanyform

www.extech.com 

RELATIVE SENSITIVITY (%)

WAVELENGTH (nm)

LT40

Altri manuali per LT40

Indice

Altri manuali Extech Instruments Multimetro

Extech Instruments

Extech Instruments EX350 Manuale utente

Extech Instruments

Extech Instruments MN62 Manuale utente

Extech Instruments

Extech Instruments 401025 Manuale utente

Extech Instruments

Extech Instruments 382065 Manuale utente

Extech Instruments

Extech Instruments Extech 470 Manuale utente

Extech Instruments

Extech Instruments EX520 Manuale utente

Extech Instruments

Extech Instruments 381676A Manuale utente

Extech Instruments

Extech Instruments 382100 Manuale utente

Extech Instruments

Extech Instruments 380941 Manuale utente

Extech Instruments

Extech Instruments EX310 Manuale utente

Extech Instruments

Extech Instruments SDL900 Manuale utente

Extech Instruments

Extech Instruments EX360 Manuale utente

Extech Instruments

Extech Instruments EX470A Manuale utente

Extech Instruments

Extech Instruments Extech 470 Manuale utente

Extech Instruments

Extech Instruments MultiLog ML720 Manuale utente

Extech Instruments

Extech Instruments MA200 Manuale utente

Extech Instruments

Extech Instruments EX530 Manuale utente

Extech Instruments

Extech Instruments MM750W Manuale utente

Extech Instruments

Extech Instruments 38387 Manuale utente

Extech Instruments

Extech Instruments MN16A Manuale utente

Extech Instruments

Extech Instruments EX623 Manuale utente

Extech Instruments

Extech Instruments MiniTec Series Manuale utente

Extech Instruments

Extech Instruments EX230 Manuale utente

Extech Instruments

Extech Instruments 411 Manuale utente

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