How to operate the Illuminometer
1. Getting ready for measurement
All you do for preparation is just to insert the LUMIDISC into position. To insert it,
match the white dot (or the red dot for low measurement) on the lumidisc to the white
dot on the swivel-head of the meter. Turn the lumidisc clockwise lightly to about 45°
until it tightly fits.
2. Ordinary measurement: 0--5000 Lx
To measure the range of 0--5000 Lx, use the lumidisc for ordinary measurement (with
a white dot at the outer ring of the disc and a green filter attached at the back).
Insert it into position as mentioned in 1. "Getting ready". Then place the meter at the
surface to be measured so that the lumidisc is parallel to the surface. Read the BLACK
figure on the scale. The figure the pointer indicates is the correct lux to use.
3. Measurement of High range: 0 --50000 Lx
To measure the range of 0--50000 Lx, use the lumidisc for ordinary measurement (see
2. above). Insert it into position in the same procedure as in 2. Then INSERT THE
SLIDE (x10 multiplier) into the slit located at the top of the swivel-head. Measure in
the same way as mentioned in 2. "Ordinary measurement". Read the BLACK figure the
pointer indicates, then MULTIPLY the figure by 10 to get the correct lux.
4. Measurement of Low range: 0--1000 Lx
To measure the range of 0-1000 Lx, use the lumidisc for low measurement (with a red
dot at the outer ring of the disc and no filter at the back). Insert it into position and
measure in the same way as in 2. Read the RED figure on the scale. Then MULTIPLY
the figure by the correction factor of each light source shown in the table below.
Mercury arc lamp...............................1.1
Fluorescent lamp ...............................1.0
Incandescent light..............................1.0
Day light..........................................0.8
In case the pointer indicates 600 Lx
under mercury arc lamp, the correct
lux is, 600 Lx X 1.1-=660 Lx
