User manual

User Manual – Rev B FCS Series II
4.5 Measurements
Standard measurements are always available through the Meas key on the front panel. These
measurements are spread across multiple screens to enhance readability. Switching between
these screens can be done by successively pressing the Meas button on the front panel. This
will cause the screen to cycle through all available measurement screens.
asic Measurements 4.5.1 B
The following three measurement screens are available:
Parameter
MEASUREMENTS 1
VOLTAGE AC rms voltage
CURRENT AC rms current
FREQUENCY Frequency
POWER Real power
MEASUREMENTS 2
VA POWER Apparent power
VAR POWER Reactive power
POWER FACT Power factor
CREST FACT Crest factor
MEASUREMENTS 3
VOLT THD Voltage distortion
CURR THD Current distortion
PEAK CURR Highest AC current found
PHASE Phase angle (relative to phase A (ø1)
Note: The V and I distortion calculations are based on H2 through H50 with the fundamental
component (H1) in the denominator.
Measurements are always running in the background. When the user selects a measurement
screen for display, the AC source first updates all the measurement parameters before
displaying the requested screen. Consequently, pressing the MEAS key may not always bring
up the selected screen immediately. There will be a perceptible delay. This will prevent the
screen from appearing with invalid or blank readouts.
4.5.2 Accuracy Considerations
Note that all measurements are AC coupled only so any DC offset will not be reported.
Any measurement system has a finite accuracy
listed in Section 2. When using the AC source
these specifications when interpreting result
pronounced as the sig easurement range. This is
II is a high power AC source
wering 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 FCS Series II uses a digital data acquisition system with a 96
Ks/sec sampling rate and 16 KHz bandwidth. This means that higher frequency components of
the measured signal are filtered out. Any contribution to the rms value of voltage and current
specification. Measurement specifications are
for measurement purposes, always consider
s. Measurement inaccuracies become more
nal being measured is at the low end of the m
particularly relevant for low current measurements. The FCS Series
optimized for providing and measuring high load currents. When po
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