Tektronix TPS2012B, User Manual

Page: 95 / 184

Math FFT
Measuring an FFT Spectrum Using Cursors
You can take two measurements on FFT spectrums: magnitude (in dB), and
frequency (in Hz). Magnitude is referenced to 0 dB, where 0 dB equals 1 V
RMS
.
You can use the cursors to take measurements at any zoom factor. To do so,
follow these steps:
1. Push the Cursor button to see the Cursor Menu.
2. Push Source ► Math .
3. Push the Type option button to select Magnitude or Freq .
4. Use the multipurpose knob to move cursors 1 and 2.
Use horizontal cursors to measure magnitude and vertical cursors to measure
frequency. The options display the delta between the two cursors, the value at
cursor 1 position, and the value at cursor 2 position. Delta is the absolute value of
cursor 1 minus cursor 2.
Magnitude cursors Frequency cursors
You can also take a frequency measurement without using the cursors. To do so,
turn the Horizontal Position knob to position a frequency component on the center
graticule line and read the frequency at the top right of the display.
TPS2000B Series Digital Oscilloscope User Manual 69