Teledyne LeCroy WaveAce - Manual (Page 59)

WaveAce Series
59 WA-GSM-E RevB
2. The Source can be any channel, but not another math trace. If you
choose subtraction, you can choose CH1-CH2 or CH2-CH1. If you
choose division, you can choose CH1/CH2 or CH2/CH1.
3. If you want to invert a waveform, press the CH1Invert or CH2Invert
option button and select On.
FFT
The FFT process mathematically converts a time-domain signal into its
frequency components. You can display only one FFT waveform at a time.
You can choose to display the FFT waveform and the channel waveform on
the screen (split screen) or to display the FFT waveform full screen. You
can choose from four Window types:
Window Type Description Test Content
1. Rectangular Best frequency resolution,
worst magnitude
resolution. This is
essentially the same as no
window.
Symmetric transients or
bursts. Equal-amplitude
sine waves with fixed
frequencies. Broadband
random noise with a
relatively slowly varying
spectrum.
2. Hanning Better frequency, worse
magnitude accuracy than
Rectangular.
Sine, periodic, and
narrow-band random
noise. Asymmetric
transients or bursts.
3. Hamming Better frequency, worse
magnitude accuracy than
Rectangular. Hamming has
slightly better frequency
resolution than Hanning.
Sine, periodic, and
narrow-band random
noise. Asymmetric
transients or bursts.
4. Blackman Best magnitude, worst
frequency resolution.
Single frequency
waveforms to find higher
order harmonics.