Wheat·stone bridge 
(wētstōn′, hwēt-) also Wheat·stone's bridge (-stōnz′)
(wētstōn′, hwēt-) also Wheat·stone's bridge (-stōnz′)n.
An instrument or a circuit consisting of four resistors or their equivalent in series, used to determine the value of an unknown resistance when the other three resistances are known.
[After Sir Charles Wheatstone (1802-1875), British physicist and inventor.]
Wheatstone bridgeThe equation to calculate the unknown resistance when the galvanometer reads 0 is Ru
= (
R2/R1
) Rv.