
Specifications 
Measuring Range of Illuminance: 
Low:  0 -1000 Lx (Red scale) 
Name of  
Parts 
Ordinary: 0-5000 Lx (Black scale) 
High:  0-50000 Lx (by using the Slide of x10 multiplier) 
Accuracy : ± 10% (tested by a standard parallel-light tungsten lamp of color 
Angle Allowance : 30'---Iess than -3% 60°---less than -10%  
Correction of  sight sensitivity  
  0-1000 Lx (No correction-light source factor used 
  0-5000 Lx (Correction used) 
Power Source : No battery used  
Condition of Use : Temperature: 5 - 35° C Humidity: 45 -85  
Accessories :  Lumidisc for low measurement 
  Lumidisc for ordinary measurement 
  Slide ( x10 multiplier) 
Dimensions : 112X58X27mm  Weight : 135g 
Characteristics :  Compact, light weight, handy to carry, and most easy -to-use 
temperature 2854°K) without including the resolution for 
the meter (the value deserves minimal scale 1/2)in this 
accuracy. 
swivel-head system 

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 

The swivel-head is one of the most advantageous features of this meter. Swivel the 
head of the meter to the right or left when the measurement is difficult due to the 
position of the surface to be measured. 
6. Zero setting adjustment 
When the light receptor is completely covered by hand (a condition where no light 
enters into the light receptor), the pointer should be at zero. If it isn't, turn the zero 
adjusting screw on the back until the pointer comes to the zero position. 
7. General Precautions 
1) Be careful not to give any shadow on the light receptor at every 
measurement. 
2) Position the meter (more exactly the surface of Lumidisc) in parallel to the 
surface to be measured. 
3) Avoid to leave the meter for long hours in a place of high temperature and 
humidity. 
4) Store it in the case and keep in a dry place when not in use. 
7-24-14, Oizumigakuen-cho, Nerima-ku, Tokyo, Japan