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User Manual
LT80
LED Light Meter
Introduction
Congratulations on your purchase of the Triplett LT80 LED Light Meter that
measures light intensity from white LED light sources. The LT80 can also
measure light from fluorescent, metal halide, high‐ pressure sodium, and
incandescent sources, for reference only (unspecified accuracy). The LT80
can measure light up to 40,000 Fc (400,000 Lux).
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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 low battery symbol
appears on the LCD.
Do not touch the meter’s circuit board for any reason; static
electricity or contamination could damage the sensitive
components.
This instrument was designed for pollution
degree 2. Operation Altitude: Up to 2000m
(7000’).
Description
1. Photo Detector Cover
2. Photo Detector (Sensor)
3. LCD Display
4. Lux/Fc Button
5. Calibration and ZERO Button
6. Data Hold Button
7. MAX/AVG/MIN Button
8. Power Button: ON/OFF
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Operation
Power ON/OFF
Long press the Power button to power the meter. To power the meter
OFF, short press the Power button.
Taking Measurements
1. Switch the meter ON and remove the sensor’s protective cover to
expose the light sensor dome. The display should switch ON; if not,
check that batteries are installed and fresh.
2. 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 this measured value on its LCD.
3. Position the meter and light source so that the light strikes the
sensor dome straight on (perpendicular) with as little an angle as
possible.
4. The meter’s display can show a value up to 9999. However, for
readings that represent measurements higher than this, the meter
uses x10 or x100 feature. For example, to represent a measurement
of 11,000 fc the meter will display 1100 with the x10 indicator.
Auto Power OFF
To save battery life, the meter powers down automatically after
approximately 12 minutes of inactivity.
Enable/Disable Auto Power Off
While the meter is ON, long press the Power button to disable the Auto
Power OFF utility (the Clock symbol will switch OFF). To enable the
Auto Power OFF utility, repeat this process.
LUX/FC Button
Press the LUX/FC button to toggle between Lux and FC (foot‐candles)
measurement units.
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MAX/AVG/MIN Button
The meter can record the maximum, minimum, and average readings as
described below:
Short press the “MAX/MIN” button and the meter will begin to track the
maximum/average/minimum measurements; the “MAX” icon will display at the
top of the LCD window indicating that the meter is now showing the maximum
reading. The reading will not change until a higher reading is registered.
Press the “MAX/MIN” button again to switch from “MAX” to “AVG”, where the
meter will show the average measurement value. The “AVG” icon will be
displayed above the displayed value.
Press the “MAX/MIN” button again to change the mode from “AVG” to “MIN”,
where the meter will show the minimum value measured. The “MIN” icon will be
displayed.
Press the “MAX/MIN” button again to switch from “MIN” back to “MAX”.
To exit this mode, hold the “MAX/MIN” button for at least 2 seconds. The
MAX/AVG/MIN icons should all be switched OFF when the unit returns to the
normal operating mode.
HOLD Button
Press the HOLD button to freeze the current reading on the LCD. Press the
HOLD button again to release the reading. In the Data Hold mode, HOLD is
displayed on the LCD.
Zero Calibration Procedure
Ensure that the protective cap is attached to the light sensor.
Power the meter and the LCD should display ‘0’.
1. Short press the “CAL ZERO” button to perform the zero adjustment
(CAL will appear on the display).
2. The CAL display will switch off when the calibration has been completed.
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3. If the protective cap is not covering the sensor when the Zero
WARNING
If the symbol “ ” appears on the LCD,
please replace the battery immediately
calibration is started the LCD display will read CAP. In this case, please
cover the sensor with the cap and restart this procedure.
Measurement Tips
For maximum accuracy allow the light being measured to fall directly on the
sensor as perpendicular as possible with a minimal angle of incidence.
When the meter is not in use, please keep the protective cap in place over
the light sensor. This will prolong the life of the sensor.
When the meter is to be stored for long periods, please remove the batteries
and store them separately. Batteries can leak and cause damage to the
meter’s components.
Avoid areas of high temperature and humidity when using this instrument.
Battery replacement
Turn off the instrument.
Remove the battery cover
Replace the battery.
Install the battery cover
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Display
9999 count, maximum display 9999
Sensor
Silicon photodiode and filter
Measuring Range
999.9,9999, 99990,400,000 Lux
99.99,999.9,9999,40,000 Footcandles
Resolution
0.1,1, 10,100 Lux
0.01,0.1,1,10 Footcandles
Accuracy
±3% ±3Lux(0~500Lux), ±3%(up 501 Lux)
(Calibrated to standard incandescent lamp 2856°K)
8% other visible light source
Angle deviation from
cosine characteristics
30°
±2%
60 °
±6%
80 °
±25%
Power Supply
2 batteries 1.5V AAA MN2400 LR03 AM4
Battery life
About 200 hours
Dimensions
133(L)x48(W)x23mm(L) Hmm
5.3(L)x 1.9(W) x0.2(L) inch
Weight
250g (include battery)
Accessories
User’s manual, carrying case, 1.5V battery*2
Specifications
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Relative Spectral Sensitivity
Lux
Foot
Lux
Foot
Candles
Candles
Factories
Home
20‐75
2‐7
Emergency Stairs, Warehouse
100‐150
10‐15
Washing
75‐150
7‐15
Exit/Entrance Passages
150‐200
15‐20
Recreational
Activities
150‐300
15‐30
Packing Work
200‐300
20‐30
Drawing Room,
Table
300‐750
30‐75
Visual Work: Production Line
300‐500
30‐50
Makeup
750‐1,500
75‐150
Typesetting: Inspection Work
500‐1,500
50‐150
Reading, Study
1,500‐3,000
150‐300
Electronic Assembly, Drafting
1,000‐2,000
100‐200
Sewing
Office
Restaurant
75‐100
7‐10
Indoor Emergency Stairs
75‐150
7‐15
Corridor Stairs
100‐200
10‐20
Corridor Stairs
150‐300
15‐30
Entrance,
Wash Room
0
10
20
30
40
50
60
70
80
90
380
440
500
560
620
680
740
V(
λ)
＊
TM - 721
100
RELATIVE SENSITIVITY (%)
Typ. Ta=23℃
WAVELENGTH (nm)
The deviation from the comparative standards for luminosity is determined by
JIS standard C 1609-1993.
Peak sensitivity wavelength: 550 nm .
Typical Light Levels (1 Fc = 10.76 Lux)
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200‐750
20‐75
Conference,
300‐750
30‐75
Cooking Room,
Reception Room
Dining Table
750‐1,500
75‐150
Clerical Work
750‐1,500
75‐150
Show Window
1,500‐2,000
150‐2000
Typing, Drafting
Store
Hospital
75‐150
7‐15
Indoors 30‐75
3‐7
Emergency Stairs
150‐200
15‐20
Corridor/Stairs
75‐100
7‐10
Stairs
200‐300
20‐30
Reception
100‐150
10‐15
Sick Room,
Warehouse
300‐500
30‐50
Display Stand
150‐200
15‐20
Waiting Room
500‐750
50‐75
Elevator
200‐750
20‐75
Medical Exam Room
750‐1,500
75‐150
Show Window,
750‐1,500
75‐150
Operating Room
Packing Table
1,500‐3,000
150‐300
Storefront, Show Window
5,000‐10,000
500‐1000
Eye Inspection
Warranty Information
Triplett / Jewell Instruments extends the following warranty to the original purchaser of
these goods for use. Triplett warrants to the original purchaser for use that the products sold
by it will be free from defects in workmanship and material for a period of (1) one year from
the date of purchase. This warranty does not apply to any of our products which have been
repaired or altered by unauthorized persons in any way or purchased from unauthorized
distributors so as, in our sole judgment, to injure their stability or reliability, or which have
been subject to misuse, abuse, misapplication, negligence, accident or which have had the
serial numbers altered, defaced, or removed. Accessories, including batteries are not
covered by this warranty
Copyright © 2020 Triplett
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