Nn. lil Ml. 



Moving-Magnet Mirror Galvanometers. 



881 



E 



61 331 B. 1:3. 



61 331 A. 1:4. 



Luminous Pointer for Galvanometry and Magnetometry after Friedr. C. G. Miiller: see under 

 No. 60,132, p. 795. 



61.325. Lecture Galvanometer after v. Beetz, Figure, with pointer reading, with one Coil 

 with thick wire 



61.326. - - i d e in, with two Coils, one with thick and one with fine wire 



This galvanometer has been essentially improved by us especially as regards ease of changing the 

 coils. It has a bell-shaped magnet and large copper damper, vertical scale visible at a distance, with 

 Mack graduations and figures on white ground, and directing magnet. The whole instrument can 

 turn about a tripod. 



61.327. Lecture Galvanometer after v. Beet/, Figure, with pointer and mirror reading, 

 with polished plane mirror, and with one Coil with thick wire 



61.328. -- idem, with two Coils, one with thick and one with fine wire ....... 



61.329. School Galvanometer after Noack, Figure (Ztschr. f. d. phys. u. chem. 1 T . 5, 

 p. 103) . . . . 



The galvanometer has two adjustable coils, vortical tangent and degree graduations easily visible, 

 bell-shaped magnet with copper damper, and can rotate on the base. It can be used both as a demon- 

 stration and differential galvanometer, as also for measurements, and can even serve as a voltmeter. 

 Total resistance, approx. 350 ohms. The scales are capable of rotation so as to be able to turn the 

 zero point towards the audience. For thermo-electric currents the galvanometer is supplied if desired 

 with coils of lower resistance. 



61.330. -- idem, with mirror, so as to be used as a reflecting galvanometer 



61.331. Large Mirror Galvanometer after Wiedemann, Figs. A and B, rotating on tripod, 

 with graduated metal prism and adjustable coils, with bell-shaped magnet and spherical 

 damper, and with ring magnet, with auxiliary weight and adjustable plate damper, with 

 polished plane mirror for telescope reading or objective projection; also with improved 

 magnet- and mirror-suspension; with one pair coils having 4x500 == 2000 turns, diffe- 

 rentially wound; the mairncts and damper pertaining thereto are each placed in one case, 

 F i g. 61,331 B . . . 



With annular magnet and auxiliary weight the galvanometer can be used as a ballistic instrument. 



d. 



6. 0.0 



7. 5.0 



7. 10. 



8. 15.0 



8. 0.0 



9. 10. 



22. 10.0 



Cl. 2365, 2366. 



