Amprobe LM631A Digital-Light-Meter - Manual (Page 8)

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RANGE Button: Each time you press ‘RANGE’ button, the range
annunciators change
DATA-HOLD Button: Press ‘HOLD’ button to toggle the DATA-HOLD
mode On and Off. In the DATA-HOLD mode, the “
H “ annunciator is
displayed and the last reading is held on the display.
Auxiliary output: The microphono jack (2.5 mm) connector output is
active as long as the light meter is turned on.
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 luminance value from the display. If magnitude of lux (or fc)
is not known, press RANGE button to the highest range and reduce until
a satisfactory reading is obtained.
6. Cover sensor head to extend sensor life.
SPECIAL CONSIDERATIONS
• Keep the plastic domed cosine corrector clean and free of scratches. It
may be cleaned with a soft cloth and isopropyl alcohol.
• 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