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5-5 Zero Function Operation
Used to offset a dark current reading.
1. Press
key to store the dark current reading and enter the
ZERO mode, the “ZERO” annunciator is displayed.
2. All subsequent reading on the LCD are relative to the previous
reading, the LCD will read :
φ
=
φ
in
-
φ
d
Where
φ
in
is the total luminous flux into the sphere at time of
measurement and
φ
d
represents the dark current reading.
3. Press
key again to exit this mode.
5-6 Ratio Function Operation
Used to display a ratio of flux measurement.
A. Use the current measured value as the reference value.
1. Press
key to store the reference value and enter the
RATIO mode, the “RATIO” annunciator and the stored reference
value are displayed. If the user press
key when the LCD
reading is 0.000 lumen, a “RATIO Err” error message will display
division by ZERO is not allowed.
2. All subsequent measurements are now displayed as the ratio of
the current measurement to the stored reference value, the LCD
will read : RATIO =
φ
φ
in
RATIO
(0<
φ
in
<OL, 0<
φ
RATIO
<OL)
Where
φ
RATIO
is the total luminous flux into the sphere when
key is pressed.
3. Press
key again to exit this mode.
ZERO
RATIO
