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OPERATOR’S MANUAL
LIGHT METER
831
831U USB & DC Power
831W Wireless
831UW USB & DC Power & Wireless
DESCRIPTION
This instrument is a portable easy use, compact-sized
digital lightmeter designed for simple one hand operation.
Provides selected the lux and fc units. Meter with Backlit
LCD display, PEAK (50mS pulse light) and HOLD feature.
Auto range or manual range selected.
WARNING
• To avoid electric shock, do not operate this product in
wet or damp conditions.
• To avoid injury or fire hazard, do not operate this
product in an explosive atmosphere.
• To avoid eye injury, wear eye protection if there is a
possibility of exposure to high-intensity rays.
• Do not immerse in liquids, clean the sensor head using
only a damp cloth.
• Cover sensor head when not in use to extend silicon
photodiode sensor life.
FEDERAL COMMUNICATIONS COMMISSION
This device complies with Part 15 of the FCC Rules.
Operation is subject to the following two conditions:(1)
this device may not cause harmful interference, and (2)
this device must accept any interference received, in-
cluding interference that may cause undesired operation.
NOTE
This equipment has been tested and found to comply
with the limits for a Class B digital device, pursuant to
Part 15 of the FCC Rules. These limits are designed to
provide reasonable protection. This equipment gener-
ates, uses and can radiated radio frequency energy and,
if not installed and used in accordance with the instruc-
tions, may cause harmful interference to radio commu-
nications. However, there is no guarantee that interfer-
ence will not occur in a particular installation If this
equipment does cause harmful interference to radio or
television reception, which can be determined by turn-
ing the equipment off and on, the user is encouraged to
try to correct the interference by one or more of the fol-
lowing measures:
- Reorient or relocate the receiving antenna.
- Increase the separation between the equipment and
receiver.
- Connect the equipment into an outlet on a circuit dif-
ferent from that to which the receiver is connected.
- Consult the dealer or an experienced radio/TV techni-
cian for help.
Shielded interface cables must be used in order to com-
ply with emission limits.
Changes or modifications not expressly approved by the
party responsible for compliance could void the user‘s
authority to operate the equipment.
WIRELESS NOTE
Wireless receiver must keep a distance at least 40cm
from the meter and meter to meter distance
must be at least 30cm.
GENERAL
Operating environment: 0°C to 50°C at < 80%R.H.
Storage temperature: -20°C to 50°C, 0 to 80% R.H.
with battery removed from meter.
Low battery indication: The “ ” is displayed when
the battery voltage drops below the operating level.
Battery: 1.5V X 4 pcs AAA size.
Battery Life: 200 hours with low battery indicator
on display.
Auto power off: 15 minutes, press power key to resume
operation.
Dimensions: 170mm(H) x 44mm(W) x 40mm(D).
Weight: Approx. 200g including batteries(1.5Vx4pcs
AAA size).
Back Side: (831/831W except)
1. USB Port
2. DC power JACK(12V)
SPECIFICATIONS
Units: lux, fc
Range: 20lux, 200lux, 2000lux, 20000lux, 200000lux,
20fc, 200fc, 2000fc, 20000fc
Resolution: 0.01lux, 0.001fc
Spectral response: CIE photopic.
Total accuracy for CIE standard illuminant A
(2856K): ±(3%rdg + 10dgts)
Accuracy: Stated accuracy at 23°C±5°C, <70% R.H.
Temperature Coefficient:
±10% of specified accuracy/°C change when tempera-
ture is out of the range between 18°C~28°C
(64.4°F~82.4°F).
Measurement rate: 1 times/second.
CIE Photopic Standard:
The CIE photopic curve is an international standard
for the color response of the average human eyes.
Spectral accuracy: ƒ'1<8%
Acceptance angle: ƒ'2<2% cosine corrected (150°)
Total accuracy for CIE standard illuminant A (2856K):
±(3.0%rdg + 10dgts)
CIE standard illuminant A can be realized by means
of CIE standard source A, which is defined as: A
gas-filled tungsten-filament lamp operating at a cor-
related colour temperature of 2856
OPERATING INSTRUCTIONS
1. “ ” Button:
When the power is off, press “ ” key to turn on the
meter. In the MAX/MIN recording mode, power off
function was disabled, unless exiting MAX/MIN mode.
2. “lux/fc” Button:
Press “lux/fc” key to change lux or fc unit.
10.764ꞏfootcandles = lux (lumens/meter2).
0.0929ꞏlux = footcandles (lumens/foot2).
3. “ ” Button:
Press “ ” key to trigger on the backlight function,
press the “ ” button again to cancel the backlight
function. The backlight will switch-off automatically
after 30 seconds.
4. “PEAK” Button:
Press “PEAK” key may toggle to show peak measure-
ment and “
” was shown on display.
Peak response time: > 50mS pulse light.
5. “MAX/MIN (▲)” Button:
Press “MIN/MAX” key to enter the “MIN/MAX” re-
cording mode and REC shows on the display. Press the
“MIN/MAX” key again to rotate through the current
readings:
MAX: The highest measurement recorded.
MIN: The lowest measurement recorded.
AVG: The average values of the measurements.
Pressing MIN/MAX button over two seconds to exit the
function.
In this mode, the APO function and other buttons are
disabled, excluding “HOLD” and Back-light buttons.
Press and hold down the “MAX/MIN” button for more
than 2 seconds to exit the MAX/MIN function.
6. “HOLD” Button:
Press the “HOLD” button to enter the data hold mode,
the “H” indicator was displayed at the left of display.
When data hold mode is selected, the meter held the
present readings and stops all further measurements.
Press the “HOLD” button again to cancel data hold
mode, and resume measuring.
In “MIN/MAX” mode, press “HOLD” button to stop
recording, all values are frozen, press “HOLD” button
again to restart recording.
7. “ZERO” Button:
Press “ZERO” key to zero adjustment for immediate
measurement, before the adjustment, must cover the cap.
Zero adjustment function can be calibrated only in the
20lux and 20fc range, the adjustment range for 0
±50dgt.
8. “SAVE (▼)“ Button:
The function saves the lux or fc data in memory. Press
the “SAVE” key to save the current data, the symbol
“MEM” is displayed to indicate the data are saved.
There are 128 data could be recorded into memory and
displayed on the top-right LCD.
9. “RANGE” Button:
Press “RANGE” button to select the manual range
mode ,and turn off the “AUTO” indicator. In the Manu-
al Range mode, press “RANGE” button to switch the
range 20lux, 200lux, 2000lux, 20000lux, 200000lux,
or 20fc, 200fc, 2000fc, 20000fc in sequence and a new
range value is displayed. Hold “RANGE” button for 2
seconds to exit the Manual Range mode, and back to
Auto-range.
10. “>5S CLR” Button:
Press “> 5S CLR” key and hold for 5 seconds to clear
the data in the memory, the “MEM” and “Clr” indicator
is displayed at upper-right LCD .
11. “RECALL” Button:
Press “RECALL” key to enter READ Mode, the
“MEM” indicator is displayed at upper-right corner.
Press “▲” or “▼” key to review the recorded data.
Press and hold down the “RECALL” key for more than
2 seconds to exit the RECALL function.
