# Agilent 34401A 6.5 Digit Multimeter (Pre-Owned) # Agilent 34401A 6.5 Digit Multimeter (Pre-Owned) ## Key Features At A Glance - 6.5-digit resolution with 0.0015% basic 24-hour DC voltage accuracy - Measures DC and true RMS AC voltage up to 1000 V, with AC bandwidth from 3 Hz to 300 kHz - Up to 1,000 readings/second direct to GPIB in ASCII format for system throughput - GPIB and RS-232 interfaces standard, plus Voltmeter Complete and External Trigger signals for test system synchronization - Three command languages standard: SCPI (IEEE-488.2), Agilent 3478A, and Fluke 8840A/8842A for software compatibility - True RMS AC measurement with AC coupling supporting up to 400 VDC bias on any range - Internal memory stores up to 512 readings; math functions include Null, Min/Max/Average, dBm, dB, and Limit Test with TTL output - Bench features including continuity, diode test, reading hold, and direct dB/dBm measurements 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. Model Resolution DC Voltage Accuracy (1 Year) AC Bandwidth **34401A** 6.5 digits 0.0035% (10 V range) 3 Hz to 300 kHz 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 Specification Value DC Voltage Ranges 100 mV, 1 V, 10 V, 100 V, 1000 V Best 24 Hour Accuracy (10 V range) 0.0015% + 0.0004% Best 90 Day Accuracy (10 V range) 0.0020% + 0.0005% Best 1 Year Accuracy (10 V range) 0.0035% + 0.0005% Measurement Method Continuously Integrating Multi-slope III A-D Converter A-D Linearity 0.0002% of reading + 0.0001% of range Input Resistance (0.1 V, 1 V, 10 V ranges) Selectable 10 MΩ or >10,000 MΩ Input Resistance (100 V, 1000 V ranges) 10 MΩ ± 1% Input Bias Current < 30 pA at 25°C Input Protection 1000 V all ranges True RMS AC Voltage Ranges 100 mV, 1 V to 750 V Basic 1 Year Accuracy (10 Hz - 20 kHz) 0.06% + 0.03% (100 mV range); 0.06% + 0.03% (1 V to 750 V) Bandwidth 3 Hz to 300 kHz Measurement Method AC coupled True RMS – measures AC component with up to 400 Vdc bias on any range Crest Factor Maximum of 5:1 at Full Scale Input Impedance 1 MΩ ± 2% in parallel with 100 pF Input Protection 750 Vrms all ranges Resistance Ranges 100 Ω, 1 kΩ, 10 kΩ, 100 kΩ, 1 MΩ, 10 MΩ, 100 MΩ Best 1 Year Accuracy (1 kΩ to 100 kΩ) 0.010% + 0.001% Measurement Method Selectable 4-wire or 2-wire Ohms. Current source referenced to LO input. Maximum Lead Resistance (4-wire) 10% of range per lead for 100 Ω and 1 kΩ ranges; 1 kΩ per lead on all other ranges Input Protection 1000 V all ranges DC Current Ranges 10 mA, 100 mA, 1 A, 3 A Best 1 Year Accuracy (100 mA range) 0.050% + 0.005% Shunt Resistance 5 Ω for 10 mA, 100 mA; 0.1 Ω for 1 A, 3 A Input Protection Externally accessible 3 A 250 V Fuse; Internal 7 A 250 V Fuse True RMS AC Current Ranges 1 A, 3 A Best 1 Year Accuracy (1 A, 10 Hz - 5 kHz) 0.10% + 0.04% Shunt Resistance 0.1 Ω for 1 A and 3 A ranges Input Protection Externally accessible 3 A 250 V Fuse; Internal 7 A 250 V Fuse Frequency and Period Voltage Ranges 100 mV to 750 V Best 1 Year Accuracy (40 Hz - 300 kHz) 0.01% Measurement Method Reciprocal counting technique Gate Time 1 s, 100 ms, or 10 ms Continuity / Diode Continuity Range 1000.0 Ω (1 mA Test Current) Diode Test Range 1.0000 V (1 mA Test Current) Response Time 300 samples/s with audible tone Continuity Threshold Selectable from 1 Ω to 1000 Ω Measurement Noise Rejection 60 (50) Hz DC CMRR 140 dB AC CMRR 70 dB Normal Mode Rejection (100 plc) 60 dB Operating Characteristics DCV/DCI/Resistance Reading Rates 0.6 to 1000 readings/s ACV/ACI Reading Rates 0.15 (Slow 3 Hz) to 50 readings/s Frequency/Period Reading Rates 1 to 80 readings/s System Speeds Configuration Rates 26/s to 50/s Autorange Rate (DC Volts) \>30/s ASCII Readings to RS-232 55/s ASCII Readings to GPIB 1000/s Maximum Internal Trigger Rate 1000/s Maximum External Trigger Rate to Memory 1000/s Triggering and Memory Reading HOLD Sensitivity 10%, 1%, 0.1%, or 0.01% of range Samples/Trigger 1 to 50,000 Trigger Delay 0 to 3600 s; 10 µs step size External Trigger Delay < 1 ms External Trigger Jitter < 500 µs Memory 512 readings Math Functions Functions NULL, Min/Max/Average, dBm, dB, Limit Test (with TTL output) Standard Programming Languages Languages SCPI (IEEE-488.2), Agilent 3478A, Fluke 8840A/42A General Power Supply 100 V / 120 V / 220 V / 240 V ±10% Power Line Frequency 45 Hz to 66 Hz and 360 Hz to 440 Hz, automatically sensed at power-on Power Consumption 25 VA peak (10 W average) Operating Environment Full accuracy for 0°C to 55°C; full accuracy to 80% R.H. at 40°C Storage Environment −40°C to 70°C Weight 3.6 kg (8.0 lbs) Safety Designed to CSA, UL-1244, IEC-348 RFI and ESD MIL-461C, FTZ 1046, FCC Vibration and Shock MIL-T-28800E, Type III, Class 5 (Sine Only) Warranty 3 years **Important:** For 2-wire ohms measurements without Math Null, add 0.2 ohm additional error per the resistance specification footnote. The published resistance accuracies apply to the 4-wire ohms function or to 2-wire ohms when using Math Null to remove lead resistance.**Important:** Option 0B0 ships the DMM without manuals; printed manuals are not included in this configuration. ## 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:** 895.0 USD - 1350.0 USD - **Vendor:** Agilent - **Type:** Multimeter - **Tags:** Agilent, Agilent Keysight, consignment-active, Manufacturers, Meters & DAQ, Multimeter, product_manual_group_1, Product_used, Updated Item Review ## Variants | Variant | Price | Available | |---------|-------|-----------| | None | 895.00 USD | In stock | | NIST Traceable | 1105.00 USD | In stock | | NIST Traceable with Full Data | 1210.00 USD | In stock | | ISO IEC 17025 Accredited | 1350.00 USD | In stock | ## Images - 34401A Agilent Multimeter - 34401A Agilent Multimeter - 34401A Agilent Multimeter - 34401A Agilent Multimeter - 34401A Agilent Multimeter --- > Source: [ValueTronics](https://valuetronics.com/products/34401a-agilent-multimeter-used) > Updated: 2026-05-30