HP 54540 Series - Automatic Parametric Measurements

Figure 13-2
Measurements
Automatic Parametric Measurements
Automatic Parametric Measurements
The illustration below shows the basic process used by the oscilloscope when
making automatic parametric measurements, like rise time, Vp-p, or
frequency. These measurements can be made on input signals, stored
waveforms, or functions.
In order to start the measurement process, the oscilloscope captures a data
record. From this data record, the oscilloscope builds a histogram, recording
how many times each q level (a q level is an internal voltage representation)
is present in the data record. From the histogram, and from the data record,
the absolute maximum and minimum voltage levels, as well as relative
maximum (top) and minimum (base) voltage levels, are determined. Using
the top and base levels, threshold levels are calculated. The data record is
again analyzed using the thresholds to determine signal edges. Finally, with
all this information, the requested parametric measurements are calculated
as shown in figure 13-2.
The oscilloscope uses this process for waveform measurement
13-3