Extech Instruments LT45 User Guide

LT45-EU-EN v1.4 9/13
4
Operation
PowerON‐OFF
MomentarilypressthePowerbuttontopowerthemeter.TopowerthemeterOFF,
momentarilypressthePowerbuttonagain.
TakingMeasurements
1. SwitchthemeterON
2. Removethesensor’sprotectivecovertoexposethelightsensordome.Thedisplayshould
switchON,ifnotcheckthatfreshbatteriesareinstalled.
3. 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themeasuredvalueontheLCD.
4. UsetheLUX/FC/CDbuttontoselectLuxorFootcandleunits(CD,luminousintensity,is
explainedinthededicatedsection‘LuminousIntensity’).When‘OL’isdisplayed,the
measurementexceedsthemeter’srangecapability.
5. Positionthemeterandlightsourcesothatthelightstrikesthesensordomeperpendicularly.
Althoughthemetercompensatesforanincidenceangle,optimumperformanceisachieved
withasmallerincidenceangle.
6. Themeter’sLCDcanshowavalueupto3999onthelargedigitsandwhenmoredigitsare
neededtorepresentthereadingtwoadditional(smaller)digitsappeartotheright
ofthe
largerdigits,e.g.3999
00
.
LUX/FC/CDUnits
MomentarypressesoftheLUX/FC/CDbuttontogglesLuxandFC(foot‐candles)units.Pressand
holdthebuttontoentertheCD(luminousintensity)mode.Referto‘LuminousIntensity’section
forfurtherinformation.
AutoPowerOFF
Tosavebatterylifethemeterpowersdownautomaticallyafterapproximately5minutesof
inactivity(nobuttonpresses).
Enable/DisableAutoPowerOff
WiththemeterON,pressandholdthePowerbuttonuntiltheAPOclocksymbol switches
OFF(theAutoPowerOFFutilityisnowdisabledandtheusermustmanuallyswitchthemeter
off).Tore‐enabletheAutoPowerOFFutility,repeatthisprocess.TheClocksymbolwillswitch
ONwhentheAutoPowerOFFutilityisre‐enabled.
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andtheADJ(adjusting)iconwillswitchONindicating
thatthezeroadjustment(calibration)isworking.Whenthecalibrationisfinished,theADJ
iconwillswitchOFFandtheme
terwillreturntothenormaloperatingmode.
4. IftheprotectivecapisnotcoveringthesensorwhentheZERO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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Extech Instruments LT45 Specifications

General

Brand	Extech Instruments
Model	LT45
Category	Measuring Instruments
Language	English