No. 61913. 



Simple Wheatstone Bridges. Standard Resistances. 



919 



61 902. 1 : 10. 



61905. 1:8. 



61 906 61 911. 1 : 4. 



61 912. 1 : 4. 



61.902. Simple Wheatstone Slide Wire Bridge for students' use, after Halm, Figure (Hahn, * <i. 

 Schiileriibungen, Fig. 314; cf. Gan.-Man. Fig. 768; Gan.-Eein., Fig. 936), without 

 comparison resistances 0.11.0 



For comparison resistances use can be made of Nos. 62,000 62,011 or the resistancas NOR. 61,850 

 to 61.865. 



61.903. Simple Wheatstone Bridge for school use, after Friedr. C. G. Miiller (M. T. Fig. 196), 

 without comparison resistances 



61.904. Double Key for above (M. T. Fig. 197) 0.12.0 



For further Double Keys see Nos. 61,144 and 61,145, p. 868. 



(i 1.005. Simple Wheatstone Bridge, Figure (M. P., 9 th Edn., Ill, Fig. 395), without 

 comparison resistances . . . 



Standard Resistances. 



Please Note. We attach special value to the construction of accurate standard resistances 

 and our laboratory is thoroughly well equipped for satisfying all requirements in this 

 connection. 



If desired, and on payment of the usual fees and postal charges, we will send 

 our standard resistances to the Physikalisch-Technische Keichsanstalt for certifi- 

 cation as precision resistances. 



Standard Resistances, Figures, of Manganin Wire, wound on metal cylinder, impre- 

 gnated with shellac and heated to 140 C. before adjustment. Enclosed in a metal 

 case and provided with bent copper leads for hanging in the mercury cups of a petro- 

 leum bath. These resistances, like all other resistances of our manufacture, are cali- 

 brated in International Ohms (1 ohm = the resistance of a column of mercury 106.3 cm 

 long and of 1 sq. mm cross section at C. 



List No. 61,906 61,907 61,908 61,909 61,910 61,911 61,912 

 Resistance 0.1 1 10 100 1000 10,000 100,000 Ohms 



2. 14. 2. 8. 2. 8. 2. 8. 2. 12. 2. 14. 3. 10. 



The load permissible for these resistances is up to 1 watt when used in the petroleum bath without 

 cooling, and for a short time in air for precision measurements and resistance-comparisons; for technical 

 current measurements the load can be as much as 10 watts. The maximum permissible currents in the 

 petroleum bath are consequently: 



Current measurements 

 Resistance Precision measurements for technical purposes 



Ohms Amperes Amperes 



100.000 0.003 .01 



10.000 0.01 0.03 



1.000 0.03 0.1 



100 0.1 0.3 



10 0.3 1 



1 1 3 



0.1 3 10 



0.01 10 30 



0.001 30 100 



0.0001 100 300 



Standard Resistance No. 61,912 of 100,000 ohms has special terminals on the limbs, see Fig. 61,912. 



61,913. Extra price for Nos. 61,906 61,911 constmcted with special terminals as per 

 Fig. 61,912 to enable the resistances to be connected direct to wires 



1. 4.0 



0. 15. 



0. 5.0 



Cl. 5744, 



5547,4691,4692. 



