I would like to know the mechanism of LCR bridge

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The LCR bridge operates similarly to a Wheatstone bridge, balancing impedance rather than resistance, which varies with frequency. By measuring the ratio of impedances, it allows for the calculation of capacitance and inductance. Modern LCR meters have largely replaced these bridges, utilizing a small sinusoidal voltage to measure current flow in the circuit. From this data, impedance is calculated using Ohm's law, enabling the determination of capacitance or inductance. Overall, the LCR bridge's theoretical foundation remains relevant, but practical applications have shifted to more advanced technology.
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Who can tell me the theory about the LCR bridge to measure capacitance?
 
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hjq_seu said:
Who can tell me the theory about the LCR bridge to measure capacitance?
Google to the rescue: lcr bridge measure capacitance

http://chem.ch.huji.ac.il/~eugeniik/instruments/test/bridges.html
 
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re

The ac bridges work just like the wheatstone bridge except you have to balance the impedance, which is dependent upon the frequency. By taking a ratio of impedances, you can calculate the capacitance or inductance as required.

The ac bridges are pretty much obsolete in modern test equipment. Today's LCR meters work by introducing a small sinusoidal voltage to a network (capacitor, inductor, resistor or combinations), and measuring the current that flows into the circuit. By the ohm's law, the impedance can be calculated Z = V/I, from which capacitance or inducance can be deduced.
 

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