Extech Instruments LT40 Manuale utente

USERGUIDE



WhiteLEDLightMeter



ModelLT40



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





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

rearofinstrument



Push‐ButtonDescription



1. Lux/Fcunitsselector

2. CalibrationandZERObutton

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

4. Dataholdbutton



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.



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.



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.



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.



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.



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.



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 381676A Manuale utente

Extech Instruments

Extech Instruments 430 Manuale utente

Extech Instruments

Extech Instruments ExStik EC500 Manuale utente

Extech Instruments

Extech Instruments MultiView Series Manuale utente

Extech Instruments

Extech Instruments EX540-NIST Manuale utente

Extech Instruments

Extech Instruments 381676 Manuale utente

Extech Instruments

Extech Instruments 410 Manuale utente

Extech Instruments

Extech Instruments 450 Manuale utente

Extech Instruments

Extech Instruments 38394 Manuale utente

Extech Instruments

Extech Instruments EX540 Manuale utente

Extech Instruments

Extech Instruments EX330 Manuale utente

Extech Instruments

Extech Instruments MO290 Manuale utente

Extech Instruments

Extech Instruments EX330 Manuale utente

Extech Instruments

Extech Instruments 380900 Manuale utente

Extech Instruments

Extech Instruments 380926 Manuale utente

Extech Instruments

Extech Instruments RHT50 Manuale utente

Extech Instruments

Extech Instruments SDL350 Manuale utente

Extech Instruments

Extech Instruments 380941 Manuale utente

Extech Instruments

Extech Instruments EX330 Manuale utente

Extech Instruments

Extech Instruments 407910 Manuale utente

Extech Instruments

Extech Instruments EX503 Manuale utente

Extech Instruments

Extech Instruments EX210 Manuale utente

Extech Instruments

Extech Instruments 450 Manuale utente

Extech Instruments

Extech Instruments 380947 Manuale utente

Manuali Multimetro popolari di altre marche

Agilent Technologies

Agilent Technologies 34420A Manuale utente

Fluke

Fluke 83 Manuale utente

Hameg

Hameg HM 8012 Manuale utente

Mastech

Mastech MY70 Manuale utente

Steren

Steren MUL-300 Manuale utente

Somogyi Elektronic

Somogyi Elektronic home SMA 92 Manuale utente

Gossen MetraWatt

Gossen MetraWatt METRAmax 6 Manuale utente

PeakTech

PeakTech 4000 Manuale per l'uso e la cura

YOKOGAWA

YOKOGAWA 90050B Manuale utente

Gossen MetraWatt

Gossen MetraWatt METRALINE DMM16 Manuale utente

Fluke

Fluke 8846A Manuale operativo e di manutenzione

Tempo Communications

Tempo Communications MM200 Manuale utente

Elenco Electronics

Elenco Electronics CM-1555 Manuale utente

Mastech

Mastech MS8238C Manuale utente

SDAR

SDAR 830A, 830B, 830D, 830C Manuale utente

RS PRO

RS PRO RS-9519BT Manuale utente

BGS technic

BGS technic 8890 Manuale utente

Amprobe

Amprobe Hexagon 60 Manuale utente