Impedance analyzers are electronic test equipment used to measure complex electrical impedance as a function of test frequency. They are mainly used for Electrochemical Impedance Spectroscopy (EIS) to investigate the electrical resistance (measured in Ohm) of substances and objects.
The key specifications of an impedance analyzer include the frequency range, impedance range, absolute impedance accuracy and phase angle accuracy. The frequency range of an impedance analyzer can vary from 1 mHz to 100 MHz, while the impedance values can range over many decades from µΩ to TΩ. The phase angle accuracy is in the range of 10 millidegree.

The accuracy of impedance measurement with an impedance analyzer is typically highly accurate, e.g. with a basic accuracy of up to 0.05%. A Impedance Analyzer has a frequency range of 20 Hz to 120 MHz and provides an industry best 0.045% (typical) basic accuracy over a wide impedance range, with a 40 V built-in DC bias source. The E5061B ENA series network analyzer with option 3L5/005 supports a wide frequency range from 5 Hz to 3 GHz, with basic accuracy of 2% (typ), 40-V built-in DC bias source, network analysis, impedance analysis, and gain/phase analysis capabilities. In addition to the frequency range and accuracy, other specifications of an impedance analyzer include the ability to apply voltage bias and current bias while measuring, and the measurement speed.

Accessories and test fixtures are also available to ensure highly accurate measurements without degrading the performance of the measurement instrument.