NEW METHODS OF ELECTRICAL EXPLORATION IN SIBERIA 



219 



6. The temperature range over which the iustruineut operates is deterinined 

 by the caj^acity of the supply sources. 



7. The relative error in the camera measurements on the lihn does not 

 exceed 2%. 



8. The input resistance of the instrument at the highest sensitivity is 

 2-3 MD. 



9. During recording visual readings can hv taken of a pt»inter. 



10. The instrinnent measures 340 x 220 :< 240 mm. 



11. The instrument, together with supply sources, does not weigh more 

 than 14 kg. 



Fig. 16. The EShO-56 oscillograph. 



Thus, if the generator group is brought to the field location, theu measure- 

 ments can be made in every case, since all the parts of the measuring 

 devices are portable. The device can be used under all earthing conditions of 

 the MN electrodes (sand, frozen earth), and its readings in practice do not 

 depend on the state of the supply sources. 



Still greater advantages are given by a new electronic measuring apparatus 

 ^dlich operates with the telluric current method. A field station -which is 

 now being Iniilt for the telluric current method is placed on the GAZ-69 motor- 

 car and includes: 



1. A 2-channel electron amplifier (weighing about 10 kg together with 



