INSTRUMENT DESCRIPTION

9

 

61-686

 

Light Meter

1

5

3

7

4

2

8

LUX

/F

LD

C

HO

 

 

AUTO

MAX

U

MAN

 

 

ZERO

6

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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IDEAL INDUSTRIES 61-686 operating instructions Instrument Description, Light Sensor Introduction