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Keysight Technologies
Viewing Graphical Results
on a DMM Display




Application Note
Introduction

Digital multimeters measure and display various parameters such as voltage, current, resistance, and
temperature in an easy-to-read number format. However, many times you are looking for more than a
single reading in the display. Often, the really meaningful information lies in the trend or statistics of a
series of readings. If your DMM offers connectivity, such as LAN or USB ports, you can transfer your
readings to a computer for computation and display. But transferring data to a PC may take more
time than you want to spend.

Now, a new DMM, the Keysight Technologies, Inc. 34461A, offers a way to get insight into your
measurement data without transferring your data to a PC. The 34461A features a large graphical
display and built-in math functions that show measurement trends, statistics, and histograms all
in a single, compact unit.




Snapshot
A company designing a high-power solar charger for smart
phones and tablets needed to rigorously test the circuit that
detected low solar-cell power for shutting down and restarting
the charging circuit smoothly. This circuit was necessary
because the charger had no internal battery to act as a buffer.
To simulate changing solar radiation, the design team used a
triangle waveform from an arb/function generator as a source.

The engineers set up the Keysight 34461A to measure the on/off
output voltage of the detector circuit and displayed the results
using the histogram mode. At frequencies below one Hertz,
the display clearly showed a binary distribution, which was the
desired result.

However, they found that for higher frequencies, which occurred
when they waved a hand across the solar panel, the circuit
exhibited an anomaly that caused an intermediate output value.
This anomaly clearly interfered with the proper output charging
operation. A relatively simple design change to the cutoff
frequency in the detector circuit solved the problem and
eliminated potential customer warranty claims.
03 | Keysight | Viewing Graphical Results on a DMM Display