Major tech MT1875, Instruction Manual, Page: 10 / 16

6.3. Measuring Light
• Set the function switch to the “Lux” scale and set the range to
desired (“Lux” or “x10 Lux”) range.
• Move the meter to face the photo detector to a light source in a
horizontal position.
• Read the illuminance nominal from the LCD display.
• Over-range: If the instrument only display one “1” in the M.S.D. the
input signal is too strong, and a higher range should be selected.
• When the measurement is completed. Remove the photo detector
from the light source.
• Spectral sensitivity characteristic: To the detector, the applied photo
diode with filters makes the spectral sensitivity characteristic almost
meet C.I.E. (International Commission on Illumination) photopia
curve V (
λ) as the following chart described.
100% (Relative Sensitivity) Spectral Sensitivity
Wave length (nm)
80%
60%
40%
20%
0
V(
λ
)
400 500 600 700
10
Recommended Illumination:
Locations
Lux
• Office
Conference, Reception room 200 to 750
Clerical work 700 to 1,500
Typing drafting 1000 to 2,000
• Factory
Packing work, Entrance passage 150 to 300
Visual work at production line 300 to 750
Inspection work 750 to 1,500
Electronic parts assembly line 1500 to 3,000
• Hotel
Public room, Cloakroom 100 to 200
Reception, Cashier 200 to 1,000