• Power measurement range: 50 μW to 12 kW
• Analog bandwidth: DC to 100 kHz
• Sampling frequency: 500 ksample/s
• 16‑bit resolution for current and voltage
• Basic accuracy: 0.05 %

Like the NPA101, the NPA501-G power meter offers basic measurements of voltage, current, power, and total harmonic distortion (THD). The 5 V measurement range provides a previously unattainable level of resolution for power and energy measurements.

The NPA501-G power analyzer offers peak value measurements, the graphical display of measured values and the analysis of up to 50 harmonics. The dual-channel trend chart function, which is unique in this instrument class, can be freely configured from 15 measurands. The inrush function captures and graphically displays inrush current and voltage waveforms. The PASS/FAIL function lets users monitor numerous measurands on the screen and externally via an analog and digital output on the rear panel. An additional sensor input for a current probe or shunt expands the instrument's current measurement range as required. The NPA501-G also comes with a GPIB interface built in; this option cannot be retrofitted to a standard NPA501.

The power meters of the R&S NPA family set standards in the documentation of measurement parameters: they simultaneously display up to 10 user-configurable measurands with a refresh rate of 10 measurements per second. A logging function lets users store this data with a timestamp in CSV format for a nearly unlimited period of time. In addition, screen content can be saved to a USB flash drive anytime at the push of a button.

The instrument's standard hardware‑based integrator delivers highly precise, seamless power consumption analysis and adds up watt and ampere hours according to polarity.

Three different filters in the voltage and current circuit of the acquisition system can be activated for the measurement task.

All instruments of the R&S NPA family can be remotely controlled via the Ethernet or USB interface. The virtual COM port and the test and measurement class (TMC) are supported for communications via USB. The remote-control commands are completely based on the SCPI standard. Cost-free driver packages for LabVIEW, LabWindows/CVI and IVI.net are also available. They allow the R&S NPA instruments to be integrated quickly and easily into existing systems.

The R&S NPA family of compact testers enable DC load, AC load and standby current characterization without PC software or remote infrastructure. In addition to a numerical and graphical display with 26 key parameters, the NPA701 models offer compliance protocols in line with IEC 62301, EN 50564 and EN 61000-3-2.

See the table below for a comparison of the models available and their primary differences. For more details, please see the datasheet in the Manuals and Guides section of this webpage.

The real-time integrator function is designed to compute and present the cumulative DUT power or energy consumption across a designated time span in both the active and standby states. Users can flexibly select their preferred acquisition mode, choosing between manual, time-based, or event-based options. Results can be delivered in various formats, including positive, negative, and total watt-hours, with continuous results in real time.

The inrush function makes it possible to graphically display switch‑on behavior. Triggering can be either manual or edge‑based (pos./neg.) when user‑defined voltage or current thresholds are reached. 8192 samples are acquired at all times with a logging period of 16 ms to 67 s.

*Note: Function included with NPA501 and NPA701 models only.

Harmonic mode enables the computing of root mean square (RMS) values and phase angles for harmonics. The accompanying bar chart elegantly visualizes patterns for up to 50 voltage and/or current harmonics, while the tabular presentation has comprehensive insights into magnitude and phase values per harmonic. Users can also selectively display odd or even harmonics. The intuitive interface allows seamless navigation through the data, with cursors or a rotary knob so that users can focus on individual harmonics, highlighted in a distinctive yellow.

*Note: Function included with NPA501 and NPA701 models only.

The R&S NPA-Z mains adapters are used for easy and safe connection of the DUT to the R&S NPA. The test adapter is like a standard AC outlet with grounded safety sockets. The three connections V, A, and COM to the power analyzers transmit the mains values for the measurement. The DUT is powered via the appliance coupler on the top of the mains adapter. Four versions cover the most common types of power plug in Europe, UK, USA (Z4 shown), China and Australia.

This graphical mode can plot up to two measured variables against time, similar to the roll mode in oscilloscopes. Primarily used observing longer time periods, it can accommodate 40 seconds to 80 minutes of data on the display. Decide on the plotting variable and adjust the time base, while the vertical trace scaling is done automatically. When operating, the numerical representations of maximum and minimum values are visible on the screen for enhanced analysis.