Xo. 61 522. 



Oscillographs. Ammeters and Voltmeters. 



901 



61 513. 1 : 6. 



61 520. 1 : 6. 



61 521. 1 : 6. 



61 521 and 61 522. 1 : 6. 



Ammeters and Voltmeters. 



Demonstration Instruments. 



61.520. Direct Current Demonstrating Ammeter, Kohlrausch's system, Figure, range 



0.2 2 amps., with 20 ampere shunt , 2. 10. 



The instrument is fitted with a scale visible from a distance and explains the construction of the 

 ammeter in a very comprehensive manner, as all parts are arranged open. The scale can be read from 

 both sides. 



61.521. Direct Current Demonstration Voltmeter, Kohlrausch's system, Figure, range 



0.5 3 volts, with additional resistance for multiplying the range ten times 2. 10. 



The Voltmeter is the same in construction as Ammeter No. 61,520 and differs from the latter 

 simply in the winding and calibration. Scale can be read from both sides. 



The current is led into both instruments by the left hand terminals. While in the case of the volt- 

 meter the sensitivity is varied and the range increased by releasing the connection between the right hand 

 terminals, in the case of the ammeter the shunt fitted on the back of the instrument is set into action by 

 inserting the connecting piece between these right-hand terminals. If approximate knowledge of the 

 voltage or current available is not known before hand, this measurement is attempled always with reduced 

 sensitivity, i. e. with resistance in series and with shunt connected. 



61.522. Glass Case with brass mount for Nos. 61,520 or 61,521, Figure. Price, each . . 0. 15. 



Cl. 3344, 5838, 

 5839, 5840. 



