Product Introduction

USB-4065 is a 6½-digit high-precision USB bus-powered digital multimeter (DMM) launched by National Instruments (NI). It does not require an external power supply and is powered directly by the USB interface. The device is compact and portable, featuring high resolution and fast reading speed. It supports various basic measurement functions such as AC/DC voltage/current, two-wire/four-wire resistance, and diode testing, and is suitable for portable high-precision signal measurement in laboratories, on-site diagnosis, and automated test systems. 

Model Interpretation

USB: Bus interface type, representing USB bus-powered and communication.

4065: The serial number of NI's digital multimeter series, specifically referring to the basic type of high-precision DMM with 6½-digit resolution and USB bus power supply. Technical Specifications

Measurement resolution: 6½ digits (10 times/second); maximum 4½ digits at 3000 times/second.

Measurement functions: DC voltage, AC voltage, DC current, AC current, two-wire resistance, four-wire resistance, diode test.

Range and accuracy:

DC voltage: ±100mV to ±300V, basic accuracy ±0.0035%.

AC voltage: 100mV to 300V (true RMS), accuracy ±0.06%.

DC current: ±100μA to ±3A, accuracy ±0.05%.

AC current: 100μA to 3A (true RMS), accuracy ±0.15%.

Resistance: 10Ω to 5GΩ (two-wire / four-wire), accuracy ±0.01%.

Isolation voltage: ±300VDC/Vrms channel-ground isolation.

Power supply and power consumption: USB bus power supply (5V), typical power consumption < 2.5W.

Size and weight: approximately 178×104×33mm, weight < 283g.

Operating environment: 0 to 50℃, humidity 10% to 90% (no condensation).

Interface and communication configuration

Host interface: USB 2.0 Type-B, plug-and-play, supports hot swapping, compatible with Windows/macOS/Linux.

Measurement input terminals: 5 banana terminals on the front panel, divided into positive/negative voltage/current, resistance/common terminal, compatible with standard test cables.

Auxiliary interface: reserved AUX interface, can be connected to accessory cables to extend trigger and synchronization functions (does not support SCXI switch control).

Driver and software: equipped with NI-DAQmx driver, compatible with LabVIEW, LabWindows/CVI, Python, etc. development environments, provides API for automated measurement programming.

Core functions

6½-digit high-precision measurement: low-noise front-end design, accurate acquisition of millivolt/microvolt level signals, suitable for precise voltage and resistance measurement.

Multi-parameter integrated testing: single device covers voltage, current, resistance, diode test, simplifies test configuration, reduces instrument switching.

High-speed reading and portable power supply: 3000 times/second at 4½ digits, meets fast dynamic measurement requirements; USB bus power supply, no need for external power supply, suitable for mobile scenarios.

High isolation safety measurement: ±300V isolation, protects equipment and personnel safety, suitable for industrial sites and high-voltage node measurement.

Automation integration capability: standard driver and programming interface, easy to embed into automated test systems, realizes multi-channel synchronous measurement and data recording. Applicable scenarios

Laboratory Precision Measurement: Component parameter calibration, sensor signal verification, high-precision testing of low-level voltages / resistances.

Field Diagnosis and Maintenance: Electrical equipment inspection, circuit board fault troubleshooting, on-board / outdoor portable signal detection.

Automated Testing System: Build a high-channel-count testing platform by combining NI switch modules for batch testing of electronic, automotive, aerospace, etc. products.

Education and Research: University laboratory teaching, data collection for research projects, construction of small-scale research platforms.

User and Maintenance Instructions Instruction Manual

Connect the USB cable to the USB 2.0 port of the computer. The device will automatically identify and install the driver, without the need for an additional power supply.

Select the corresponding terminal according to the measurement function, connect the test cable to the object being tested, and ensure that the connection is firm without short circuits.

Set the range and function through the software or panel. The 6½ digit is used for high-precision slow measurement, and the 4½ digit is used for high-speed acquisition.

When measuring high voltage (>100V), pay attention to safety and avoid touching the exposed terminals; for large current (>1A) measurement, control the duration to prevent overheating.

During automated measurement, configure the trigger and sampling parameters through the DAQmx API to ensure data synchronization and stability.

Maintenance instructions

Store in a dry and ventilated environment, away from dust, corrosive gases and strong electromagnetic interference, and avoid direct sunlight.

Regularly check the insulation layer of the test cable and terminals for any damage, oxidation or loosening, and replace aging components in time.

Before cleaning the equipment, turn off the power supply, wipe the casing and terminals with a dust-free soft cloth, and do not allow liquids to come into contact directly to avoid damaging the internal circuit.

When not in use for a long time, disconnect the USB cable, remove the test cable, store it in a cool and dry place, avoid squeezing and violent vibration.

Avoid over-range and reverse voltage input to prevent internal circuit damage; in case of a fault, contact the official after-sales service, do not attempt to disassemble and repair yourself.