IMl'KDANCK BHlUCiKS VOH M lU; ACM LI", ll\\(;K 



1007 



i-()t()i' switch oil which are mounted (ix'c uncalibi'titcd mica capacitors 

 which ciiahic cs to moasui'c liotli positive and ncji;ati\(' reactance \ahies 

 up to 10,000 njjif without adcHtioiial switching!;. 'The 20 ju/a/ cii capacitor 

 covers capacitance measurements u]) to 00 ^fj.f\ the 40 /x/x/' capacitoi- 

 covers up to 150 nfif; the 80 ^jlhJ up to 000 mm'': '!»' '40 mm/ up to 10,000 

 MM./; iiiid th(> 200 ^ijjif capacitor covers all the posit i\-e series reactance 

 measurements. Since the cr capacitor permits the l)ri(l}2;e to be balanced 

 with the test leads short-circuited, the value of the effective resistance 

 under test is simply etjual to the difference between RS readings for the 

 measui'cmcnt balance and the short-circuit balance, and the reactance 

 under test is determined from a computation of the two r(>adinji;s of cs. 

 A front N'iew of the geneiiil purpose bridge is shown in Fig. (i. 'Die four 

 lower dials are for gp; a})ove them ai'e the four us dials; and aboxc them 

 is the CR dial. The capacitors cs and cp are located adjacent to the test 

 terminals, but are operated remotely by the dial knobs at the extreme 

 right end of the bridge. This was done to remove the operatoi''s hands as 

 far as possible from the test terminals. Near the test terminals is a coaxial 

 connector engraved a. This allows plug-in capacitors (cu in Fig. 5) to 

 be added in parallel with cp for extending the capacitance range. Com- 

 pact silvered mica capacitors in steps of 200 ^ifxf are used. Fig. 7 shows 

 the interior of the same bridge with cp and cs in the lower foreground, 

 GP at the left and rs in the upper right. 



Fig. 6 — Front view of the general -i)uii)()sc bridge shown in Fig. 5. The t)ri(lgo 

 is appro.ximately 10| inches high and 19 inches wide. 



