THE LOCALISATION OF BREAKS AND FAULTS. 



433 



1908, in wliicli useful hints on carrying out the test, the galva- 

 nometer suspension, battery power, application of corrections, 

 &c., are given. 



The Sullivan galvanometer has been used for this test 

 with differentially wound coils, and Fig. 247A shows differ- 

 ential coils as suspended for shore and shipboard instruments 

 specially for this test. 



One very valuable feature of the method is the greater appre- 

 ciation attainable in proportion as the resistance of the break is 



Fig. 247a. — Sullivan Galvanometer Coils, doubly wound. 

 (The upper spiral encircles but does not touch the suspending wire.) 



greater. Mr. Kempe, in his standard "Handbook of Electrical 

 Testing," gives a method by bridge for localising a break 

 making partial earth, in which two galvanometers and a special 

 key are employed, and the observations are by discharge, but 

 the working out is somewhat lengthy, and Mr. Eymer- Jones' 



F F 



