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OPERATING INSTRUCTIONS
Push buttons
Peak-Hold Switch:
Press "PEAK" button to toggle in and out of the PEAK-HOLD mode. The "
indicator is displayed. (Response Time: >50mS)
Display Back-Light Button
Pressing "
" button to turn on the Back-Light.
Pressing "
" button to turn off the Back-Light.
HOLD (DATA-HOLD) Button
Press "HOLD" button to toggle in and out of the DATA-HOLD mode. In the
DATA-HOLD mode, the "
"indicator is displayed and the last reading is held
H
on the display.
OPERATION
1. Set the function switch to the desired lux or fc units.
2. Remove the sensor head cover.
3. Hold the sensor head steady and make certain that the light source
completely fills the cosine correction dome.
4. Move away from the sensor head to avoid shadowing it. The sensor head
has a 1.5 meter cable to allow separation between the observer and the
measurement location.
5. Read the illuminance value from the display. If magnitude of lux (or fc) is not
known, set RANGE switch to the highest range and reduce until a satisfactory
reading is obtained.
6. Cover sensor head to extend sensor life.
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SPECIAL CONSIDERATIONS
• Keep the plastic domed cosine corrector clean and free of scratches. It may
be cleaned with a soft cloth and isopropyl alcohol.
"
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• When light is received from many directions simultaneously, take special care
to avoid reflections or shadowing the sensor with your body.
• For best accuracy, repeat the measurement several times to ensure that the
light source has remained stable.
• Avoid flexing the cable excessively at either end of the cable.
• The Inverse-square Law
The law states that the illuminance E at a point on a surface varies directly with
the intensity I of a point source, and inversely as the square of the distance d
between the source and the point. If the surface at the point is normal to the
direction of the incident light, the law is expressed by E=I/d
• Cosine Law
The law that the illuminance on any surface varies as the cosine of the angle of
incidence. The angle of incidence θ is the angle between the normal to the
surface and the direction of the incident light. The inverse-square law and the
cosine law can be combined as E=(I cos θ )/d
Cleaning
Periodically wipe the case with a damp cloth, do not use abrasives or solvents.
2
.
2
.
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