Dc Measurements; Rms Measurements; Minimum And Maximum Measurements; Power Measurements - Keysight N3300A User Manual

General Information - 2
As shipped from the factory, front panel measurements for input voltage and current are calculated from a total
of 1000 readings taken at a 10 microsecond sampling rate. There are no trigger controls for front panel
measurements. However, you can program both the sampling rate and the number of data points in each front
panel measurement using commands in the Sense menu. With this flexibility, measurement accuracy can be
improved for waveforms with frequencies as low as several Hertz. The sample buffer size may be varied from 1
to 4096 data points. The sampling rate may be varied from 0.00001 seconds to 0.032 seconds. Values are
rounded to the nearest 10-microsecond interval.

DC Measurements

DC voltage and current is measured by acquiring a number of readings at the selected time interval, applying a
windowing function to the readings, and averaging the readings. Windowing is a signal conditioning process
that reduces the error in dc measurements made in the presence of periodic signals such as line ripple. At
power-on and after a *RST command, the interval and number of sample points used for the measurement
acquisition is set. Ripple rejection is a function of the number of cycles of the ripple frequency contained in the
acquisition window. More cycles in the acquisition window results in better ripple rejection. In addition, the
speed of the measurement can be increased by reducing the number of sample points.
To measure the dc input voltage or current using the front panel, press the Meter key. The display indicates the
present voltage and current reading. Scroll to the appropriate measurement. To measure the voltage or current
over the GPIB, use the MEAS:VOLT? or MEAS:CURR? command.

RMS Measurements

To measure the rms of the input voltage or current, press the Meter key and scroll to the V RMS or A RMS
menu commands. To measure the rms voltage or current over the GPIB, use MEAS:VOLT:ACDC? or
MEAS:CURR:ACDC?
This returns the total rms measurement, including the dc portion.

Minimum and Maximum Measurements

To measure the maximum or minimum voltage or current, press the Meter key and scroll to the
V MAX, V MIN, A MAX, or A MIN menu commands. Minimum returns the lowest value in the array;
maximum returns the highest value in the array. To measure the maximum/minimum voltage or current over the
GPIB, use MEAS:VOLT:MAX?/MEAS:VOLT:MIN? or MEAS:CURR:MAX?/MEAS:CURR:MIN?

Power Measurements

To measure the average, maximum, or minimum power, press the Meter key and scroll to the
WATTS, W MAX, or W MIN menu commands. Power is calculated from the latest voltage and current
measurements. Use MEASure:POWer? to measure power over the GPIB.

Measurement Ranges

The electronic load has two measurement ranges. The commands that control the measurement ranges are
located in the front panel Sense menu. To change measurement ranges, scroll to the S:C:RNG or the S:V:RNG
commands and enter a value that falls within the range that you wish to set. The electronic load will pick the
range with the best resolution for that value. The corresponding SCPI range commands are:
SENS:CURR:RANG and SENS:VOLT:RANG.
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