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The Keysight 34420A is a high-sensitivity nanoVolt/micro-Ohm meter optimized for low-level measurements. It combines low-noise voltage measurements with resistance and temperature functions in a single benchtop instrument, providing 7½ digit resolution with 100 pV voltage sensitivity and 100 nΩ resistance sensitivity. The instrument is RoHS compliant and applies to serial numbers MY61000101 and SG61000101 onwards.
The 34420A is designed to take the uncertainty out of low-level measurements. Low-noise input amplifiers and a highly tuned input protection scheme bring reading noise down to 8 nVpp on the 1 mV range over a 2-minute observation period. Combined with 7½ digits of resolution, selectable analog and digital filtering, 2 ppm basic 24-hour DC voltage accuracy, and a shielded copper pin connector, the instrument supports accurate, repeatable measurements for nanoVolt-class work.
ValueTronics International stocks and supports the Keysight 34420A from our 20,000 sq ft secure warehouse at 1675 Cambridge Drive, Elgin, Illinois. Every nanoVolt-class instrument we list is inspected and performance-verified by our technicians before shipment, so the condition grade and specifications you see in the listing reflect what the instrument actually delivered on our bench — not a seller's description. We've supported customers across calibration labs, semiconductor characterization groups, and standards laboratories since 1992, and we back every unit with our standard performance warranty.
The 34420A traces to Hewlett-Packard's test and measurement heritage. HP spun off its T&M business as Agilent Technologies in 1999, and Agilent then transferred its electronic measurement business to Keysight Technologies in 2014. Instruments in this product family have carried the HP, Agilent, and Keysight brand marks across the lineage, with full software, accessory, and calibration support continuity through Keysight today.
| Accuracy Specifications ± (% of reading + % of range) | ||||||
|---|---|---|---|---|---|---|
| Function | Range | Test current | 24-hour 23 °C ± 1 °C | 90 day 23 °C ± 5 °C | 1 year 23 °C ± 5 °C | Temperature coefficient 0 °C to 18 °C / 28 °C to 55 °C |
| DC voltage | 1.0000000 mV | — | 0.0025 + .0020 | 0.0040 + .0020 | 0.0050 + .0020 | 0.0004 + .0001 |
| 10.000000 mV | — | 0.0025 + .0020 | 0.0040 + .0002 | 0.0050 + .0003 | 0.0004 + .0001 | |
| 100.00000 mV | — | 0.0015 + .0003 | 0.0030 + .0004 | 0.0040 + .0004 | 0.0004 + .00006 | |
| 1.0000000 V | — | 0.0010 + .0003 | 0.0025 + .0004 | 0.0035 + .0004 | 0.0004 + .00004 | |
| 10.000000 V | — | 0.0002 + .0001 | 0.0020 + .0004 | 0.0030 + .0004 | 0.0001 + .00002 | |
| 100.00000 V | — | 0.0010 + .0004 | 0.0025 + .0005 | 0.0035 + .0005 | 0.0004 + .00005 | |
| Resistance | 1.0000000 Ω | 10 mA | 0.0015 + .0002 | 0.0050 + .0002 | 0.0070 + .0002 | 0.0005 + .00002 |
| 10.000000 Ω | 10 mA | 0.0015 + .0002 | 0.0040 + .0002 | 0.0060 + .0002 | 0.0005 + .00001 | |
| 100.00000 Ω | 10 mA | 0.0015 + .0002 | 0.0040 + .0002 | 0.0060 + .0002 | 0.0005 + .00001 | |
| 1.0000000 kΩ | 1 mA | 0.0015 + .0002 | 0.0040 + .0002 | 0.0060 + .0002 | 0.0005 + .00001 | |
| 10.000000 kΩ | 100 µA | 0.0015 + .0002 | 0.0040 + .0002 | 0.0060 + .0002 | 0.0005 + .00001 | |
| 100.00000 kΩ | 10 µA | 0.0015 + .0003 | 0.0040 + .0004 | 0.0060 + .0004 | 0.0005 + .00002 | |
| 1.0000000 MΩ | 5 µA | 0.0020 + .0003 | 0.0050 + .0004 | 0.0070 + .0004 | 0.0006 + .00003 |
| DC Voltage Noise | |||
|---|---|---|---|
| Range | 2-minute RMS noise | 2-minute peak-peak noise | 24-hour peak-peak noise |
| 1 mV | 1.3 nVrms | 8 nVpp | 12 nVpp |
| 10 mV | 1.5 nVrms | 10 nVpp | 14 nVpp |
| 100 mV | 10 nVrms | 65 nVpp | 80 nVpp |
| 1 V | 100 nVrms | 650 nVpp | 800 nVpp |
| 10 V | 450 nVrms | 3 µVpp | 3.7 µVpp |
| 100 V | 11 µVrms | 75 µVpp | 90 µVpp |
| Measurement Characteristics — DC Voltage | |
|---|---|
| Measurement method | Continuously integrating multi-slope III A-D Converter |
| A-D linearity | 0.00008% of reading + 0.00005% of range |
| Input resistance | 100 V (Ch1 only): 10 MΩ ± 1%; 1 mV through 10 V: > 10 GΩ, in parallel with < 3.6 nF |
| Input bias current | < 50 pA at 25 °C |
| Injected current | < 50 nA pp at 50 or 60 Hz |
| Input protection | 150 V peak any input terminal to Channel 1 LO, continuous; Channel-to-channel switching error (typical): 3 nV |
| Channel isolation | Isolation between input channels > 10^10 Ω |
| Earth isolation | 350 V peak any input terminal to earth; Impedance from any input terminal to earth is > 10 GΩ and < 400 pF |
| Maximum voltage | Channel 1 LO to Channel 2 LO, 150 V peak |
| Measurement Characteristics — Resistance | |
|---|---|
| Measurement method | Selectable 4-wire or 2-wire ohms; Current source referenced to Channel 1 LO input |
| Offset compensation | Used on all ranges except 100 kΩ and 1 MΩ; Can be turned off if desired |
| Protection | 150 V peak |
| Open circuit voltage | For resistance and low power resistance < 14 V; 20 mV, 100 mV, 500 mV selectable clamp |
| Measurement Characteristics — Temperature | |
|---|---|
| SPRT | ITS-90 calibrated temperature with the range of -190 °C to +660 °C |
| Thermocouple | Type B, E, J, K, N, R, S, T | Range: -210 °C to 1820 °C |
| Thermistor | 5 kΩ | Range: -80 °C to 150 °C |
| RTD | 4-wire, 4.9 Ω to 2.1 kΩ; types: a = .00385 (DIN/IEC 751) and a = .00391; Range: -200 °C to 850 °C |
| Measurement Noise Rejection 60 (50) Hz | |
|---|---|
| dc CMRR | 140 dB |
| ac CMRR | 70 dB |
| Operating Characteristics | |||
|---|---|---|---|
| Function | Digits | Integration time | Readings/s (60 Hz / 50 Hz) |
| DCV thermocouple | 7.5 | 200 plc | .15 (.125) |
| DCV thermocouple | 7.5 | 100 plc | .3 (.25) |
| DCV thermocouple | 6.5 | 20 plc | 1.5 (1.25) |
| DCV thermocouple | 6.5 | 10 plc | 3 (2.5) |
| DCV thermocouple | 5.5 | 1 plc | 25 (20.8) |
| DCV thermocouple | 5.5 | 0.2 plc | 100 (100) |
| DCV thermocouple | 4.5 | 0.02 plc | 250 (250) |
| Resistance | 7.5 | 200 plc | .075 (.062) |
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.
Model No
Keysight
Condition
New
Manufacturer
Keysight
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