Screen, block, or direct all task 

 light sources so that they cannot 

 glare in the workers' eyes. 



Select similar dark colors for 

 equipment parts and woricer clothing 

 in the sorting area so that bright areas 

 cannot interfere with the wooers' 

 established vision conditions. 



u 





I 



Use SP-30 (or equivalent) 

 illumination at the sorting area of 

 most fresh produce pacldnglines. 



z: 



:x 



(o o od) 



Adjust lamp power levels (number of 

 tubes) and fixture height so that light- 

 colored produce receives approximately 

 250 foot-candles of illumination and 

 dark-colored produce, approximately 

 SOO foot-candles of illuminadon. 



Minimize the influence of 

 natural, stray, and general area 

 lighting in the sorting area. 



..o oo 



Use a dark background color (black, gray, dark brown) on 

 the conveyor surface carrying the produce so that reflected 

 light energy from this surface is not greater than that from 

 the produce; avoid a glossy finish on the surface of the belt 



Figure 2. Primary design and management criteria for lighting at sorting areas. 



which are black or dark gray, but not glossy finish. 



Surrounding colors. 

 Surfaces near sorting areas and the clothing of inspec- 

 tion personnel should not be bright or highly reflective 

 and should not cause glare. 



Placement of fixtures. 

 Placement should be such that the light source will not 

 be directly in the sorters' eyes, i.e., unshielded, or too 

 low so as to obstruct the sorters' view or the sorting 

 surface. The fixture also must be placed at such a height 

 as to provide the proper level of light at the sorting 

 surface. This wiU depend on the amount and type of 

 light used and the considerations mentioned above. For 

 an SP30 light, this height will be about 32 inches above 

 the sorting surface, as shown in Figure 2. 



Type of lighting . 

 Light type should be appropriate for the sorting task and 

 the colors involved. Area lighting also should be 

 considered as it can have negative impacts on the color 

 evaluation and on eye-strain. 



For more information, the following references are 

 listed. 



1. Affeldt, H. A. and P.W. Winner. 1991. Lighting 

 practice and principles for manual citrus inspec- 

 tion. Paper No. 9 1 3549, AS AE, 2950 Niles Rd. , St. 

 Joseph, Ml 49085. 



2. Brown,G.K. 1991. Lighting for manual sorting of 

 apples and sweetcherries. Paper No. 913553, 

 ASAE, 2950 Niles Rd., St. Joseph, Ml 49085. 



Fruit Notes, Fall, 1994 



