User manual

LT45-EU-EN v1.4 9/13
2
Introduction
CongratulationsonyourpurchaseoftheExtechLT45LEDLightMeterthatmeasureslightfromLED
lamps in addition to fluorescent, metal halide, high‐pressure sodium and incandescent sources.
The LT45 is capable of measuring the illumination of white, red, yellow, green, blue, and purple
LEDsupto400,000Lux(40,000Fc).
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TheLT45canalsocalculateluminousintensity(CD)usingadistance‐to‐the‐lightvalueprogrammed
bytheuserinmetersorfeetunits.
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The LT45 can store up to 99 readings for later recall and includes Overload indication, Battery
status icon, Data hold, Maximum/Average/Minimum (MAX/MIN) tracking, push‐button
 Zero
calibrationadjustment,AutoPoweroff(withdisablefunction),andautorangingfeatures.
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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.
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Features
 OverloadIndication:LCDscreenwillshow“OL”attheupperleft‐handcorner
 Batterystrengthstatus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theintensityofilluminationofwhite,red,yellow,green,blue,andpurpleLED
lightandallvisiblelightinLuxorfoot‐candles
 CalculatesLuminousIntensity(CD)
 Dataholdfreezesdisplayedreading
 Maximum/Average/MinimumMemoryHold
 Zeroadjustment
 Autopoweroffwith
disablefunction
 Automaticrangeadjustoptimizesaccuracyandresolution
 Manuallystore/recallupto99readings
 Completewithlightsensor,protectivesensorcover,andcoiledcableexpandableto59”
(1.5m),9Vbattery,andhardshellcase