The Agilent 34401A is a 6.5-digit digital multimeter designed to deliver high-resolution, high-accuracy measurements for both benchtop and system testing applications. The instrument combines 6.5-digit resolution with 0.0015% basic 24-hour DC voltage accuracy and a throughput of up to 1,000 readings per second directly across the GPIB bus, providing a balance of precision and speed in a single chassis. Per its product overview, the 34401A measures DC and true RMS AC voltage up to 1000 V, resistance from 100 ohms to 100 megohms, DC and AC current to 3 A, frequency and period, continuity, and diode test.

According to the datasheet, the 34401A was designed with bench needs in mind, and built-in functions commonly associated with bench operation include continuity and diode test, a Null feature for removing lead resistance and other fixed offsets, min/max/average readouts, and direct dB and dBm measurements. For systems use, the instrument provides faster bus throughput than other DMMs in its class according to Agilent's stated positioning, with standard GPIB and RS-232 interfaces, Voltmeter Complete and External Trigger signals for synchronization with other instruments, and a TTL output that indicates Pass/Fail when limit testing is active. The 34401A also stores up to 512 readings in internal memory and supports a reading hold feature for troubleshooting.

Brand Heritage

Hewlett-Packard spun out its test and measurement business as Agilent Technologies in 1999, and Agilent's electronic measurement division became Keysight Technologies in 2014. Instruments originally branded HP and Agilent — including the 34401A — therefore carry the same engineering lineage that continues at Keysight today.

Compare Other Models in This Series

The 34401A is presented in this datasheet as a single multimeter model rather than as part of a multi-tier family. Its capability set — 6.5-digit resolution, 0.0015% basic 24-hour DC voltage accuracy, 1000 V measurement range, true RMS AC to 300 kHz, and 1,000 readings/second over GPIB — places it in the bench precision DMM segment as configured.

Configuration choices on the 34401A are handled through options rather than separate model numbers: rack mounting (Option 908), additional documentation or no documentation (Options 910 and OBO), extended warranty (Option W50), and MIL-STD-45662A calibration with data (Option 1BP). The Test Lead Kit, manuals, calibration certificate with test data, test report, and power cord are listed as included accessories.

Each pre-owned 34401A listed below is its own product page with condition-matched pricing. Selecting the listing that fits your specifications, calibration requirement, and option configuration ensures the unit you receive matches the documented condition grade and accessory complement.

For applications that depend on the 34401A specifically — legacy production test procedures referencing the model number, scripts written against the Agilent 3478A or Fluke 8840A/8842A command languages also supported by this instrument, or rack systems that already integrate the 34401A's GPIB and trigger I/O — exact-model continuity is usually the goal. The datasheet's documented support for SCPI, Agilent 3478A, and Fluke 8840A/8842A command languages is the specific reason customers maintaining older test code frequently specify this unit by name.

This product page covers the 34401A as documented. Differentiation between listings comes primarily from condition grade, calibration status, included accessories, and installed options such as Option 908 rack mounting or Option 1BP MIL-STD-45662A calibration with data.

When comparing listings, confirm which options are present on the specific unit, whether a current calibration certificate is included, and whether the Test Lead Kit and documentation match your requirements. The comparison table that follows summarizes the headline specifications and standard configuration of the 34401A as presented in the datasheet.

Additional differences in specifications beyond the few shown above are not listed here — see each model's full specifications below.

Accessories Supplied

• Test Lead Kit with probe, alligator, and grabber attachments
• IntuiLink connectivity software
• Operating manual
• Service manual
• Calibration certificate
• Test report
• Power cord

Product Core & Specifications

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.