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HANDBOOK OF MAGNETIC COMPASS 



ponent parts. In most cases it is best to create this compensating 

 field, by a combination of three vectors on axes arranged mutually 

 90° apart, rather than by one vector adjusted at the proper angle. 

 This renders compensation completely electrical. 



Figure 38 illustrates the conception of a resultcmt degaussing mag- 

 7ietic -field across a compass as having three separate components, 

 mutually 90° apart. 



114. The various standard compass coil installations utilize a three- 

 coil arrangement^ of one type or another, to achieve compensation by 

 the three-component method. Such a group of coils are so inter- 

 connected that they can be indimdually adjusted,' and each group is so 

 connected to its associated degaussing coil that its compensation ef- 

 fect will automatically change with changes in the degaussing coil 

 effect. 



VERTICAL COMPONENT 



HORIZONTAL 

 COMPONENTS 



RESULTANT 



DEGAUSSING 



FIELD 



COMPASS 

 FrouKE 38. — Resultant degaussing field and its equivalent three vector components. 



