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.
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61-686
Light Meter
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