General Tools DLM112SD User Manual

DLM112SD

USER’S MANUAL

LIGHT METER WITH

DATALOGGING SD CARD

Please read this manual carefully and thoroughly before using this product.

TABLE OF CONTENTS

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Key Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Operating Instructions . . . . . . . . . . . . . . . . . . . . . 4 – 11

What’s in the case . . . . . . . . . . . . . . . . . . . . 4 –5

Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 –8

Normal Operation . . . . . . . . . . . . . . . . . . . . . 8 –9

Holding and Storing Measurements. . . . . . . . . . 9

Automatic vs. Manual Datalogging . . . . . . 9 – 10

Transferring Data from the SD Card

to a Computer . . . . . . . . . . . . . . . . . . . . . . 10 – 11

Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Maintenance & Troubleshooting Tips . . . . . . . . . . . . 13

Optional Accessories. . . . . . . . . . . . . . . . . . . . . . . . . 13

Warranty Information . . . . . . . . . . . . . . . . . . . . . . . . 13

Return for Repair Policy . . . . . . . . . . . . . . . . . . . . . . 14

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INTRODUCTION

Thank you for purchasing General Tools & Instruments’ DLM112SD UV Light Meter
with Datalogging SD Card. Please read this user’s manual carefully and thoroughly
before using the instrument.

The DLM112SD is a general-purpose handheld instrument suitable for measuring
the intensity of light in commercial, industrial and consumer settings. Applications
include photography, videography, construction, engineering and surveillance.

This light meter measures light intensity using either of two units: lux or foot-candles.
The lux is the standard international unit of illuminance, or how much luminous flux
is spread over a given area. One can think of luminous flux as a measure of the total
“amount” of visible light present, and illuminance as a measure of the intensity of
illumination on a surface. A given amount of light will illuminate a surface more dimly
if it is spread over a larger area, so illuminance is inversely proportional to area.

The standard international unit of luminous flux is the lumen, and one lux is equal to
one lumen/m2. For perspective on lux readings from the natural world, consider that
a moonless clear night sky has an illuminance of about 0.002 lux, while direct
sunlight has an illuminance of 30,000 to 130,000 lux.

The footcandle (or lumen per square foot) is a non-standard unit of illuminance.
Like the Btu, it is mainly in common use only in the U.S., particularly in construction­related engineering and in building codes. Because lux and footcandles are different
units of the same quantity, it is perfectly valid to convert footcandles to lux and vice
versa. One footcandle (ft-cd) = 10.764 lux.

The DLM112SD has the performance and features needed to satisfy the most
demanding aspects of the above applications. It also has the ability to measure
surface temperature, using an optional Type K of Type thermocouple. A light probe
comes standard with the instrument.

Because it is microprocessor-based, the DLM112SD can make full use of the
portability, reliability and large storage capacities that SD memory cards offer.
Measurements of light intensity or temperature can be made automatically at any
of 11 sampling rates between one second and one hour. After time-stamping and
storing the measurements on an SD card plugged into the instrument (a process
called datalogging), the user can remove the card and transfer the measurements
to a laptop or desktop computer either directly or via a USB card reader.

The DLM112SD has a backlit 2-1/2 in. diagonal display and is powered by six “AA”
Alkaline batteries or an optional 9-VDC AC adapter.

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KEY FEATURES

• Includes light probe

• Measures light intensity within three automatically switched full-scale
ranges: 2,000 lux, 20,000 lux and 100,000 lux (200 ft-cd, 2,000 ft-cd and
10,000 ft-cd)

• Selectable lux or foot-candle unit

• Displays maximum and minimum readings

• Performs real-time automatic datalogging at sampling time settable from
1 second to 1 hour

• Also supports manual logging and changing of card storage location

• Accepts SD memory cards of up to 16 GB capacity

• Big (2.5 in. diagonal) front-panel green backlit LCD is easy to read

• Auto power off function

• Powered by six “AA” batteries or optional 9V AC/DC adapter

OPERATING INSTRUCTIONS

WHAT’S IN THE CASE

The DLM112SD comes fully assembled in a carrying case along with a light
probe with a protective cover, a 2 GB SD memory card and this user’s manual.

Optional accessories available from General Tools & Instruments include Type K
and Type J thermocouples and a 9VDC adapter for a 110V power supply. See
the Replacement Parts & Optional Accessories section of this manual for more
details.

Figure 1 shows all of the controls and indicators on the front, back, top, bottom
and right side of the DLM112SD. It also shows (at right) the main components
of the supplied light probe. Familiarize yourself with their positions and
functions before moving on to the setup procedure.

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Fig. 1

TOP

FRONT

1-1 Liquid-crystal display
1-2 POWER/ESC button
1-3 FUNC./HOLD/NEXT button
1-4 REC/ENTER button
1-5 SET ▼ button
1-6 LOGGER ▲ button
1-7 Socket for light probe
1-8 Socket for Type-K or -J

thermocouple temperature probe
1-9 SD card socket
1-10 RS232 output jack

RIGHT

SIDE

BOTTOM

BACK

1-11 RESET Button
1-12 Socket for 9VDC AC adapter
1-13 Battery compartment cover
1-14 Battery compartment cover

screws
1-15 Kickstand
1-16 Tripod attachment nut
1-17 Light probe plug
1-18 Light sensor housing
1-19 Light sensor
1-20 Light sensor cap

1. The DLM112SD’s controls and indicators and other physical features

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