Extech Instruments LT40 Manual de usuario

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.



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

Otros manuales para LT40

Tabla de contenidos

Otros manuales de Multímetro de Extech Instruments

Extech Instruments

Extech Instruments DM4750D Manual de usuario

Extech Instruments

Extech Instruments 381676A Manual de usuario

Extech Instruments

Extech Instruments EX503 Manual de usuario

Extech Instruments

Extech Instruments MultiPro MP510 Manual de usuario

Extech Instruments

Extech Instruments SD750 Manual de usuario

Extech Instruments

Extech Instruments 38390 Manual de usuario

Extech Instruments

Extech Instruments 407735 Manual de usuario

Extech Instruments

Extech Instruments MN10 Manual de usuario

Extech Instruments

Extech Instruments 382100 Manual de usuario

Extech Instruments

Extech Instruments EX420-NIST Manual de usuario

Extech Instruments

Extech Instruments MultiTec MT310 Manual de usuario

Extech Instruments

Extech Instruments MN26-NIST Manual de usuario

Extech Instruments

Extech Instruments EX410A Manual de usuario

Extech Instruments

Extech Instruments MiniTec Series Manual de usuario

Extech Instruments

Extech Instruments 38394 Manual de usuario

Extech Instruments

Extech Instruments SDL900 Manual de usuario

Extech Instruments

Extech Instruments 45170 Manual de usuario

Extech Instruments

Extech Instruments MiniTec Series Manual de usuario

Extech Instruments

Extech Instruments MultiMaster MM560A Manual de usuario

Extech Instruments

Extech Instruments EX410A Manual de usuario

Extech Instruments

Extech Instruments 38387 Manual de usuario

Extech Instruments

Extech Instruments EX320 Manual de usuario

Extech Instruments

Extech Instruments EX542 Manual de usuario

Extech Instruments

Extech Instruments 411 Manual de usuario

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