Agilent HP 34401A

Overview of the HP 34401A Digital Multimeter

  • Status: Obsolete, Discontinued
  • Similar Models: HP 34401A, Agilent 34401A, Keysight 34401A
  • Replaced by Keysight 34461A and Keysight 34465A

The HP 34401A is a versatile and reliable digital multimeter widely used in various electrical and electronic testing applications. It is known for its high accuracy, extensive measurement capabilities, and robust design, making it a preferred choice for professionals in fields such as electronics, electrical engineering, and laboratory testing.

Features of the HP 34401A

  • High Accuracy and Precision
  • DC voltage accuracy: Up to 0.0035% for 1-year specifications.
  • 6.5-digit resolution for precise measurements.
  • Measurement Capabilities
  • Voltage: Measures AC and DC voltage up to 1000V.
  • Current: Measures AC and DC current up to 3A.
  • Resistance: Measures resistance from 100 μΩ to 100 MΩ.
  • Frequency: Measures frequency from 3 Hz to 300 kHz.
  • Capacitance: Includes capacitance measurement capabilities.
  • Continuity and Diode Test: Built-in functions for testing continuity and diodes.

HP 34401A digital multimeter specifications:

Specification CategoryDetails
Measurement Functions
DC Voltage Range100 mV to 1000V
AC Voltage Range100 mV to 750V
DC Current Range100 μA to 3A
AC Current Range100 μA to 3A
Resistance Range100 Ω to 100 MΩ
Frequency Range3 Hz to 300 kHz
Capacitance Range1 nF to 10,000 μF
DC Voltage Accuracy±(0.0035% + 0.0005% of reading)
AC Voltage Accuracy±(0.06% + 0.03% of reading)
DC Current Accuracy±(0.05% + 0.04% of reading)
AC Current Accuracy±(0.15% + 0.05% of reading)
Resistance Accuracy±(0.01% + 0.002% of reading)
Frequency Accuracy±(0.01% + 0.003% of reading)
Capacitance Accuracy±(1% + 0.5% of reading)
Display TypeDigital LCD
Display Digits6.5 digits
Display Count1,200,000 counts
Special Features
True RMSYes
Min/Max RecordingYes
Data LoggingYes, with built-in memory
Connectivity and Interfaces
InterfacesIEEE-488 (GPIB), RS-232
Remote ControlYes
Power Supply100V/120V/220V/240V AC, 45-66 Hz
Environmental Specifications
Operating Temperature0°C to 55°C (32°F to 131°F)
Storage Temperature-40°C to 75°C (-40°F to 167°F)
Humidity80% up to 40°C; 70% up to 55°C
Physical Specifications
Dimensions88 x 213 x 348 mm (3.5 x 8.4 x 13.7 inches)
Weight3.6 kg (8 lbs)
Safety and Compliance
Safety RatingCAT I 1000V, CAT II 300V
ComplianceIEC 61010-1, UL, CSA, and CE
This table provides a clear and concise view of the HP 34401A digital multimeter’s specifications.
  • User Interface
  • Clear and bright 6.5-digit display for easy reading of measurements.
  • Intuitive front panel with straightforward operation.
  • Connectivity and Compatibility
  • IEEE-488 (GPIB) and RS-232 interfaces for remote control and data logging.
  • Compatible with various test and measurement software.
  • Data Logging and Storage
  • Built-in memory for storing measurement data.
  • Allows for efficient data logging and analysis.
  • Robust Design
  • Durable and reliable construction for long-term use.
  • Suitable for both bench-top and field applications.
  • Additional Features
  • Auto-ranging capability for ease of use.
  • True RMS AC voltage and current measurements for accurate readings.
  • Multiple measurement functions integrated into one device.


The HP 34401A digital multimeter is a high-performance instrument designed for precise and reliable electrical measurements. Its extensive features, high accuracy, and robust design make it a valuable tool for professionals in various technical fields.

NOTE: High performance test equipment may be worthy of repair and calibration even though it has been labeled obsolete and is discontinued.

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