Tektronix Waveform Monitors WFM700 Series - Manual (Page 75)

Reference
3- 26 WFM700 Series Waveform Monitors User Manual
Measurement Accuracy Using the Measurement Cursors. If you use the measure-
ment cursors to measure jitter, you may measure a different result than that
shown in the jitter measurement box for the following reasons:
H The internal peak detector does a better job of measuring jitter excursions
than a human can when using their naked eye to position the cursors
H The noise floor is removed from the jitter measurement readout but not from
the cursor delta readout
Manually Measuring Timing Jitter. Perform the following steps to manually
measure the timing jitter:
1. Perform the steps in Setup for Eye Measurements on page 3--17.
2. Select the 3 EYE mode, which shows peak jitter at each eye crossing.
3. Select the 10 Hz bandwidth filter to measure the total broadband jitter (use
this setting if composite D/A conversion is planned).
4. Position the timing cursors to measure the width of the Eye zero-crossing
point (see Figure 3--9). If necessary, use the Gain and Sweep menus for
better vertical and horizontal resolution.
5. Check that delta between the two timing cursors is less than the following
over one horizontal line:
H SD signals: 740 ps (0.2 unit intervals per SMPTE259M)
H HD signals: 673 ps (1.0 unit interval per SMPTE292M)
Figure 3- 9: Timing Cursors alignment for measuring timing jitter