Extech Instruments LT40 User Manual page 2

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 "

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').
".
2
" appears on the LCD.
LT40-EU-EN v1.3 9/13