Objective: In this bridge, a capacitance is measured with a standard variable capacitance.The connection is shown in the figure.
C1= A standard capacitor.
C2= A standard capacitor whose capacitance has to be measured.
r1,r2= Represanting loss of their corresponding capacitors.
R4,R3= Non-inductive resistance.
R1,R2= They are connected in series with C1 and C2 repectively.
At balance condition,
Equatting both the real and imaginary parts and separate them,
The balance may be obtained by variation of resistances R1, R2, R3 and R4.
The angles and are the phase angles of capacitor C1 and C2.The dissipation factor for corresponding capaqcitor are
From the above equation ,
Thereforw, if the dissipation factor of one of the capacitors is known, the dissipation factor for the other can be determined .