PPA45xx Quick User Guide
Page 15
Bandwidth
The bandwidth setting dictates the frequency range of
the instrument. This selection sets an inline analogue
filter as per the selection
Wide (dc - 2MHz)
HC Version (dc – 1MHz)
Wide bandwidth will offer the full range of frequency
components available for analysis
Low (dc - 200KHz)
Low bandwidth may be useful in noisy applications for
example
where
there
are
switching
spikes
superimposed on the waveform of interest. The
switching spikes may push the input channels onto a
higher range than is necessary for the measurement.
Selecting low bandwidth puts a hardware filter in the
analogue input path to eliminate unwanted high
frequency components
dc (dc – 5Hz)
The DC only bandwidth option applies a dc-accurate
low pass filter of around 10Hz to reduce the ac signal.
This is particularly useful when accurately measuring
the dc content of an ac waveform such as the output
of a UPS (uninterruptible Power Supply). A 50Hz or
60Hz ac signal would not be removed entirely so that
the measurement may still be synchronised to the
waveform, but the amplitude would be greatly
reduced so that the instrument would be on a more
appropriate range for the dc component