892 



Voltaic Electricity. Section 3: Electro-Magnetic Current Measurements. 



No. til (_:; 



61 441. 1 : 0. 



61 443 A. 1:7. 



61 443 B. 



Zeiss Optical Apparatus for No. 61,422. 



61.423. Achromat A 1 



61.424. Achromat A with iris diaphragm 2 







61.425. Achromat AA 1 



61.426. Achromat C 



61.427. Achromat DD 



61.428. Micrometer Ocular 3 graduated over the entire field of view 



61.429. Projection Ocular No. 2 



61.430. Projection Ocular No. 4 



61,431. Small Permanent Magnet String Galvanometer, Figure, with simple microscope 



for direct reading with micrometer ocidar of approx. magnification of 60, including case 9. 5.0 



This small simplified string galvanometer is very practical for many experiments where the maximum 

 sensitivity is not required. It can be also used for projection for photographic recording and if desired 

 is arranged to fit the optical bench of a projection lantern. Further particulars on application. 



With quartz fibre (approx. lo.ooo ohms resistance) and a magnification of 100 the following 

 sensitivity can be reached when adjusted aperiodically : 1 mm deflection = 8 x!0~ 7 amp.; with cxtra- 

 aperindic adjustment 1 mm = 3.2xlO~ 10 amp.; with 140 ohm gold fibres the corresponding sensi- 

 tivities are: 7.5xlO- 8 and 3xlO~ 8 amp. 



t;i,.|32. Small Electro-Magnet String Galvanometer, Figure, with simple microscope as 



in No. (il.131 13. 0.0 



The sensitivity is about 3 4 times as great a in No. 61,431. 



Photographic Recording Apparatus and other Accessories for String Galvanometers quoted 

 for on application. 



(il.133. Alternating Current Reflecting Galvanoscope after \\einhold (\\. I)., Fig. 5X8) . . 2. o. o 



< 1. :u>, 3.'i>. '.'389, 

 SIM, .'illlli. 



s. (1. 



i'. o 



0. ii 



13. (I 



13.0 



15. o 



3.0 



4.0 



4.0 



