888 



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



No. HI ::'.il - 



61 394. 1 : 6. 



61 395. 1 : 6. 



61 396. 1 : 6. 



61 397. 1 : 10. 



61 398. 1 : 4. 



61.394. Universal Shunt connected up by Ayrton's method, for No. 61,392, F i g u r e, also 

 suitable for other Galvanometers of 100 ohms max. resistance; total resistance 10,000 ohms 

 with stages of 1, 1 / 10 , 1 / 100 , Viooo> Vioooo- The ratio of damping therefore remains approxi- 

 mately constant 3. n. o 



61.395. Connecting Switchboard for No. 61,392, Figure, for regulating the sensitivity and 

 damping 3. I. o 



The variation of sensitivity cannot, of course, be measured in this instance, but can easily be i 

 manipulated so that the device is very practical especially for zero methods. 



61.396. Simple Moving Coil Mirror Galvanometer, for school use, Figure; approx. resis- 

 tance of coil, 20 ohms 1. 10. 



61.397. -- idem, with Reading Telescope, Figure, for firmly fixing, preferably to a 



wall between two windows 3. '). () 



61.398. Moving Coil Mirror Galvanometer after Ayrton-Mather, Figure :>. o. o 



As a rule the resistance of the coil is about 325 ohms. If desired we can supply, in place of this, 

 cods with other resistances, e. g., about 14, 95, 1000 ohms or any other values. Coils of 325 loon ohm-- 

 are charged 0. 10, extra. In ordering it should be stated whether the coils arc to be used aperiodi- 

 c-ally or ballistic-ally. The coils together with suspension can be, interchanged forthwith, cf. Fig. (i 1.399. 

 The time of swing of the ballistic coils is about .'! seconds. The chief advantage of these Calvano- 

 meiers is their simple, massive construction and ease of manipulation. The sensitivity at .'i2."> ohms 

 is: 1 mm at 1 m distance =- approx. 2xlO~ 8 amp. 



Interchangeable Coil together with Tube Suspension, F i g u r e, for preceding ('.ah -anomeier, 

 aperiodic or ballistic construction. 



List No. 61,399 61,400 61,401 61,402 



Approx. Resistance 14 95 .">l'."i l(KM) ohms 



2.0.0 2.0.0 2.0.0 2.10.0 



61,403. Moving Coil Mirror Galvanometer after A\ rion -.Mather, specially constructed for 



school use, Figure 6. <. (i 



This iralvanoineter is arranged so that the outer covering can lie reinoM-d lor showing thu 



internal construction. As regards resistance of the coils, sensitivity and prices of -pan il>. the same 



remarks applies as in No. (il .3!)S--(il .402. 



cl. .-.Till, .-.IIP.'. 55I7, 

 5508, 5384. 



