234 



M. N. Berdichevskii 



for 70° < < 110° from tenths of a percent to 2-3 per cent. For angles O 

 of the order of 60° (120°) or 50° (130°) the error m determining q^ becomes 

 5-8% as shown by calculations. 



It follows that when carrying out azimuthal probes, it is generally desir- 

 able to use an arrangement with angles from 70 to 110°, and the unreel- 

 ing of the measuring lines should have an accuracy of 1—1.5°. Measurements 

 within the limits of the rising branch of the KS curves, inclined to the axis 

 of the distances at an angle close to 45°, can be conducted with angular 

 errors in the direction of the measuring line, reaching 3-4°, without much 

 effect on the KS values. 



Fig. 6. 



(b) The effect of inaccuracy of sighting the feed line on the KS values — 

 We will consider an azimuthal arrangement of which the feed line A'B' 

 is laid with a certain angular error y with respect to the given direction 

 AB (Fig. 6). 



The error in the KS value, connected with the angular error y will be 

 characterized by the value 



r = ^^— ^100% = -^-1)100%, 

 Qa \ Qa 



(19) 



where : q^' is the KS value obtained with an inaccurate sighting of the feed 

 line; 



Q^ is the KS value obtained with an accurate sighting of the feed line. 



It is apparent that 





