User Manual
AMETEK Programmable Power
RS Series
113
4.5.3 Accuracy Considerations
Any measurement system has a finite accuracy specification. Measurement specifications are
listed in Section 2. When using the AC source for measurement purposes, always consider
these specifications when interpreting results. Measurement inaccuracies become more
pronounced as the signal being measured is at the low end of the measurement range. This is
particularly relevant for low current measurements. The RS Series is a high power AC and DC
source optimized for providing and measuring high load currents. When powering low power
loads, measurement inaccuracies on rms and peak current measurements will greatly affect
derived measurements such as power, power factor and crest factor.
The measurement system on the RS Series uses a data acquisition system with a 16 kHz
bandwidth. This means that high frequency components of the measured signal are filtered out.
Any contribution to the rms value of voltage and current above this cutoff frequency will not be
reflected in the RS Series measurements. When using an external measurement reference, this
may account for discrepancies in readings.
4.6 Advanced Measurements
The 3Pi controller offers advanced power analyzer measurement capabilities. These functions
may be accessed from the MEAS button or the MENU 2 screen. The phase for which the
analysis or waveform acquisition is done may be selected using the PHASE key in three phase
configurations. This chapter covers the use and application of these advanced measurement
functions.
4.6.1 Harmonic Analysis
The 3Pi controller’s power analyzer performs fast Fourier transformation (FFT) on both voltage
and current on each available phase. The resulting frequency spectrum can be displayed on the
LCD display in a tabular as well as a graphical mode.
4.6.1.1 Acquiring FFT data
To perform an FFT analysis on the output of the AC source, proceed as follows:
1. Press the MEAS button four times or until the HARMONICS/TRACE ANALYSIS screen
appears.
2. Move the cursor to the FUNCTION field and select VOLT or CURR. (The BOTH selection
will default to CURR as only one FFT result can be displayed at a time.)
3. Move the cursor to the VIEW field and select the TABLE or BAR display mode. The TRACE
display mode does not apply to FFT results.
4. Move the cursor to the DATA MODE field and select ABS or REL. Absolute display mode
will show all harmonic components in volts or amps. Relative display mode will use the
fundamental as a 100 % reference and display all harmonics as a percentage of the
fundamental. Phase angles are always shown with respect to the fundamental frequency.
The phase angle of the fundamental is always shown with respect to phase A.
5. Skip the SCALE field as it only applies to the TRACE display mode.
6. Move the cursor to the TRIG MODE and select SINGLE or CONT. The SINGLE mode will
acquire the data once and show the result. If you select CONT, the data will be updated
continuously.
7. Move the cursor to the TRIG SOURCE field and select IMM. We will cover additional trigger
modes later.
Summary of Contents for RS180-3Pi
Page 1: ...M440036 01 Rev G www programmablepower com RS Series AC and DC Power Source User Manual...
Page 58: ...User Manual AMETEK Programmable Power RS Series 58 Figure 3 14 Functional Test Setup...
Page 133: ...RS Series 133 Figure 5 3 Power Module Detailed Block Diagram...
Page 173: ...User Manual AMETEK Programmable Power RS Series 173 Figure 9 4 Voltage Modulation...
