Keysight (Agilent) 42091A Short Termination, 4-Terminal Pair

The Keysight (Agilent) 42091A is a precision short termination accessory engineered for 4-terminal pair (Kelvin) connections. It establishes a low-impedance reference point essential for accurate calibration and characterization of impedance measurement equipment. By providing a well-defined, repeatable short circuit, the 42091A minimizes residual inductance and resistance at measurement terminals, enhancing accuracy across higher frequencies.

Technical Specifications

• Connection Type: 4-Terminal Pair (Kelvin)


• Nominal Impedance: Near-zero impedance across operational frequency range


• Residual Inductance: Exceptionally low


• Residual Resistance: Extremely low


• Connector Type: Precision-manufactured connectors for 4-terminal pair connections

Key Features

• Minimizes errors from residual inductance and resistance in test leads and fixtures


• Provides repeatable, well-defined short circuit reference


• Precision manufacturing ensures consistent performance


• Durable construction maintains electrical performance in laboratory and production environments


• Compact, bench-friendly design

Typical Applications

• Calibration of impedance analyzers


• Calibration of LCR meters


• Residual impedance compensation procedures


• High-frequency impedance characterization

Compatibility & Integration The 42091A works with impedance analyzers and LCR meters employing 4-terminal pair measurement techniques. Its legacy Agilent branding indicates compatibility with older model test instruments utilizing this connection architecture.