Anritsu MX183000A, Operation Manual, Page: 106 / 226

Chapter 4 Operation
4-52.
Intermediate results as shown in Figure 4.7.3-4 can be obtained for
settings as shown in Table 4.6.2-1.
Unit: Error Rate
Error Threshold: 1.0E–10
Direction Search: Binary
Figure 4.7.3-4 Example Intermediate Measurement Results for Binary,
Error Threshold 1.0E–10
In this case, as there are only two measurement results with an error
rate between 1.0E–6 and 1.0E–9, the approximation line shown in Figure
4.7.3-1 cannot be drawn, and BER cannot be estimated for low rates such
as E–20.
If Unit is set to Estimate, measurement can be continued until three
measurements are obtained between 1.0E–6 and 1.0E–9 by adding SJ
values, but additional measurement is not performed when Unit is set
other than to Estimate.
If you wish to determine jitter tolerance estimate results accurately for
low rates, set Unit to Estimate.