Extech Instruments LT45 User Manual page 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).
The LT45 can also calculate luminous intensity (CD) using a distance‐to‐the‐light value programmed
by the user in meters or feet units.
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.
This instrument is shipped fully tested and calibrated and, with proper use, will provide years of
reliable service. Please visit our website 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

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
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