2
INSTRUMENT DESCRIPTION
1.
Display(LCD):
Displays measurements and function symbols
2.
Power Button:
Switches the meter on and off.
3.
LUX/FC:
Unit of measure button
4.
MAX:
Maximum hold button
5.
HOLD:
Data hold button
6.
MANU:
Manual range button
7.
AUTO:
Auto range button
8.
ZERO:
Auto zero button
9.
LIGHT SENSOR
INTRODUCTION
The 61-686 meter measures light from fixtures that are equipped with fluores-
cent, metal halide, high-pressure sodium and incandescent light sources.
The foot-candle unit is defined as the amount of illumination the inside
surface an imaginary 1-foot radius sphere would be receiving if there were a
uniform point source of one candela in the exact center of the sphere. Alterna-
tively, it can be defined as the illuminance on a 1-square foot surface of which
there is a uniformly distributed flux of one lumen. This can be thought of as
the amount of light that actually falls on a given surface. The foot-candle is
equal to one lumen per square foot.
The SI derived unit of illuminance is the lux. One foot-candle is equal to
approximately 10.764 lux, although in the lighting industry, typically this is
approximated as 1 footcandle being equal to 10 lux.
61-686
Light Meter
LUX/FC
HOLD
MANU
MAX
AUTO
ZERO
1
5
9
6
7
4
2
8
3
