# Keysight E4990A Impedance Analyzer, 20 Hz to 10/20/30/50/120 MHz (Pre-Owned) # Keysight E4990A Impedance Analyzer, 20 Hz to 10/20/30/50/120 MHz (Pre-Owned) ## Key Features At A Glance - Frequency range from 20 Hz to 120 MHz (Option 120); also available in 10, 20, 30, and 50 MHz upper-limit options - Four-terminal pair measurement configuration with BNC connectors; convertible to 7 mm port via 42942A adapter or SMA port via 42941A probe (Option 120) - Test signal level: 5 mVrms to 1 Vrms with 1 mV resolution; current signal level 200 µArms to 20 mArms - DC bias: 0 to ±40 V and 0 to ±100 mA with constant voltage and constant current modes - 1601 measurement points per sweep; segment sweep with up to 201 segments for application-specific test profiles - 10.4-inch XGA color LCD (TFT) with 4 data + 4 memory traces per channel and equivalent circuit analysis (3- and 4-component models) - GPIB, LAN (10/100/1000 Base-T, LXI Class C), USB device (USBTMC-USB488), and USB host interfaces for ATE integration - 36-pin handler interface with TTL pass/fail, sweep-end, and 24-bit I/O signals for production sorting The Keysight E4990A Impedance Analyzer measures impedance parameters across a frequency range from 20 Hz up to 120 MHz, depending on the configured upper-frequency option. The instrument supports a comprehensive set of impedance and admittance parameters — |Z|, θz, |Y|, θy, Cp, Cs, Lp, Ls, Rp, Rs, D, Q, X, G, B, and complex Z and Y — along with AC and DC voltage and current level monitoring. A four-terminal pair measurement configuration with BNC connectors provides the foundation for low-impedance and high-impedance characterization, and Option 120 units can be reconfigured to a single-port test interface using the 42942A Terminal Adapter (7 mm port) or the 42941A Impedance Probe (SMA port). Engineers use the E4990A for component characterization, materials research, and frequency-dependent impedance analysis. The published specifications cover applications including capacitor and inductor measurement under DC bias, equivalent circuit parameter extraction (3-component and 4-component models with frequency-response simulation), and production component sorting via the integrated 36-pin handler interface. The signal level monitor reports actual voltage and current at the device under test, supporting measurements where the test signal must be precisely controlled — including DC voltage bias to ±40 V and DC current bias to ±100 mA, with constant-voltage and constant-current bias modes for active and reactive device evaluation. ValueTronics International stocks, inspects, and tests precision impedance analyzers like the E4990A in our 20,000 sq ft facility at 1675 Cambridge Drive, Elgin, Illinois. Every used instrument we ship is bench-verified by our technicians before it leaves the building, and every quote we send carries a direct contact path back to the person who built it. This is the model we have operated since 1992: deep test-and-measurement expertise across roughly 120 manufacturers, in-house inspection rather than drop-shipped surplus, and accountability that you can call back when a question arises after delivery. ## Brand Heritage Keysight Technologies was formed in 2014 when Agilent Technologies divided its operations and spun off its electronic measurement business as a standalone company. Agilent itself was created in 1999 from Hewlett-Packard's measurement, semiconductor, and life-sciences divisions. Impedance analyzers in this product family carry forward a measurement-instrument lineage that traces from Hewlett-Packard through Agilent to Keysight. ## Product Core & Specifications Category Parameter Specification Basic Measurement Impedance parameters |Z|, θz, |Y|, θy, Cp, Cs, Lp, Ls, Rp, Rs (R), D, Q, X, G, B, Complex Z, Complex Y Basic Measurement Level monitor Vac, Iac, Vdc, Idc Measurement terminal Configuration Four-terminal pair configuration Measurement terminal Connector type Four BNC (female) connectors. Option 120: Can be converted to one port terminal using the Keysight 42942A Terminal Adapter (7-mm port) or 42941A Impedance Probe (SMA (f) port). Source Frequency Range 20 Hz to 120 MHz (Option 120); 20 Hz to 50 MHz (Option 050); 20 Hz to 30 MHz (Option 030); 20 Hz to 20 MHz (Option 020); 20 Hz to 10 MHz (Option 010) Source Frequency Resolution 1 mHz Source Frequency Accuracy (without Option 1E5) ± 7 ppm ± 1 mHz (at 23 ± 5 °C) Source Frequency Accuracy (with Option 1E5) ± 1 ppm ± 1 mHz (at 23 ± 5 °C) Source Frequency Stability (without Option 1E5) ± 7 ppm (at 5 to 40 °C, Typical) Source Frequency Stability (with Option 1E5) ± 0.5 ppm (at 5 to 40 °C, Typical); ± 0.5 ppm per year (Typical) Voltage Signal Level Range 5 mVrms to 1 Vrms Voltage Signal Level Resolution 1 mV Voltage Signal Level Accuracy (4-terminal pair / 7-mm port of 42942A) ± \[(10 + 0.05 × f)% + 1 mV\] Voltage Signal Level Accuracy (42941A / 16048G/H) ± \[(15 + 0.1 × f)% + 1 mV\] Current Signal Level Range 200 µArms to 20 mArms Current Signal Level Resolution 20 µA Output Impedance Output impedance 25 Ω (nominal) DC Bias DC voltage bias range 0 to ± 40 V DC Bias DC voltage bias resolution 1 mV DC Bias DC voltage bias accuracy ± \[0.1% + (5 + 30 × |Imon|) mV\] DC Bias DC current bias range 0 to ± 100 mA DC Bias DC current bias resolution 40 µA DC Bias DC current bias accuracy ± \[2% + (0.2 + |Vmon|/20) mA\] DC Bias Output impedance 25 Ω (nominal) Sweep Available sweep parameters Frequency, signal voltage, signal current, DC bias voltage, DC bias current Sweep Sweep type Linear frequency, log frequency, OSC level (voltage, current), DC bias (voltage, current), log DC bias (voltage, current) Sweep Sweep direction Up sweep, down sweep Sweep Number of measurement points 2 to 1601 points Sweep Number of segments 1 to 201 Sweep Delay time range 0 sec to 30 sec Sweep Delay time resolution 1 msec Trigger Trigger type Continuous, single, averaging Trigger Trigger source Internal (free run), external (BNC connector input), GPIB/USB/LAN, manual (Front key) Trigger Trigger event type Point trigger, Sweep trigger Measurement Time Range 1 (fast) to 5 (precise), 5 steps Averaging Type Sweep-to-sweep averaging, point averaging Averaging Averaging factor 1 to 999 (integer) Display Size/type 10.4-inch color LCD (TFT) Display Number of pixels 1024 x 768 (XGA) Display Data traces 4 traces per channel Display Memory traces 4 traces per channel Marker Marker count 10 independent markers per trace Equivalent Circuit Circuit model 3-component model (4 models), 4-component model (3 models) Interfaces GPIB 24-pin D-Sub (Type D-24), female; compatible with IEEE-488 Interfaces USB host port Universal serial bus jack, Type A; female Interfaces USB (USBTMC) interface port Type B (4 contacts inline); compatible with USBTMC-USB488 and USB 2.0 Interfaces LAN 10/100/1000 Base T Ethernet, 8-pin configuration Interfaces Video output 15-pin mini D-Sub; female; drives VGA compatible monitors Handler Interface Connector type 36-pin centronics, female Handler Interface Signal type Negative logic, opto-isolated, open collector output Measurement Circuit Protection Max discharge withstand voltage 1000 V @ C < 2 µF, √(2/C) V @ C ≥ 2 µF Operating Environment Temperature +5 °C to +40 °C Operating Environment Humidity 20% to 80% at wet bulb temperature < +29 °C (non-condensation) Operating Environment Altitude 0 to 2,000 m (0 to 6561 feet) Operating Environment Vibration 0.21 Grms maximum, 5 Hz to 500 Hz Non-operating Environment Temperature \-10 °C to +60 °C Non-operating Environment Humidity 20% to 90% at wet bulb temperature < +40 °C (non-condensation) Non-operating Environment Altitude 0 to 4,572 m (0 to 15,000 feet) Non-operating Environment Vibration 2.09 Grms maximum, 5 to 500 Hz External Reference Input Frequency 10 MHz ± 10 ppm (Typical) **Important:** Discharge capacitors before connecting them to the UNKNOWN terminal or a test fixture. Maximum discharge withstand voltage: 1000 V at C < 2 µF, or √(2/C) V at C ≥ 2 µF.**Important:** Discharge capacitors before connecting them to the UNKNOWN terminal or a test fixture. Max discharge withstand voltage: 1000 V @ C < 2 µF, √(2/C) V @ C ≥ 2 µF.**Important:** Specifications apply at 23 °C (± 5 °C), 90 minutes after the instrument has been turned on. Beyond 23 ± 5 °C, the measurement accuracy is twice as bad as described.**Important:** Test fixtures and adapters (such as the 16047E direct connection fixture, 16048G/H four-terminal pair cables, 42942A Terminal Adapter, or 42941A Impedance Probe) are not supplied with the analyzer and must be ordered separately based on the DUT geometry. See the Accessories Catalog for Impedance Measurements (5965-4792E) and the E4990A Configuration Guide (5991-3891EN) for selection.Recommended pairing: for Option 120 units, the Keysight 42942A Terminal Adapter (7 mm port) and 42941A Impedance Probe (SMA port) convert the four-terminal pair front panel to a single-port test interface — each with its own documented measurement accuracy specifications in the data sheet. ## About this used unit - Warranty included - Functional verification included - Standard Calibration Upgrade Options: No Calibration Required, NIST Traceable, Z540.1 or ISO 17025 with Data, Z540.3 Guardbanding with Data. - Note that unnecessary accessories may not be included (contact Test Architect to confirm). **Please review the Manufacturer's Data Sheet to verify published specifications. Feedback on this webpage is always welcome — please reach out to your Test Architect at any time for questions or concerns. Thank you, we truly appreciate you being our customer.** ## Details - **Price:** 0.0 USD - 1540.0 USD - **Vendor:** Keysight - **Type:** Impedance Analyzer - **Tags:** Agilent, Agilent Keysight, Analyzers, Impedance, Manufacturers, product_manual_group_1, Product_used ## Variants | Variant | Price | Available | |---------|-------|-----------| | None | 0.00 USD | In stock | | NIST Traceable | 910.00 USD | In stock | | NIST Traceable with Full Data | 1120.00 USD | In stock | | ISO IEC 17025 Accredited | 1540.00 USD | In stock | ## Images - Keysight E4990A Impedance Analyzer, 20 Hz to 10/20/30/50/120 MHz (Pre-Owned) --- > Source: [ValueTronics](https://valuetronics.com/products/e4990a-agilent-impedance-analyzer-used) > Updated: 2026-05-30