KPS -LX20 Manual De Funcionamiento página 32

foot, all points of which are one foot from a uniform source of one candela.
4.2.2 Unit conversion for illuminance scales
• 1 Fc = 10,764 lux
• 1 lux = 0,09290 Fc
4.2.3 Conversion formula for illuminance and light intensity
• E = I / r 2
When
- E: illumination value (unit: Lux)
- I: light intensity of the light source (unit: cd)
- r: distance from the luminous surface of light source to the optical detector
(unit: m).
During the measurement, the minimum distance between the luminous surface
of light source and the opto-sensor should be more than 15 times greater than
maximum size of the luminous surface (or opto-sensor).
4.3 Typical practice cases
• In the following practice cases, the user stands under a light source. Remo-
ve the protection cover of the KPS-LX20 multifunctional light meter sensor
and place it at right angle to the light source, as shown in figure 4-1.:
• Press and hold the KPS-LX20 power key (4) for a short time to power on the
light meter. The LCD screen will illuminate (about 5 seconds) with the buzzer
beeping twice, and "AUTO" will appear on the middle of LCD display. This
KPS-LX20 • Digital light meter
Figure 4-1
32