CHAPTER 3. FRONT PANEL OPERATION
14
•
The crest factor is 6. The value Upk or Ipk of the input signal exceeds 660% of the current range setting.
Principles of automatic range level decrease:
The range level is decreased when all of the following conditions are satisfied.
•
Urms or Irms is less than or equal to 30% of the current measurement range.
•
The crest factor is 3. The value Upk or Ipk of the input signal is less than 300% of the range at the following
level.
•
The crest factor is 6. The value Upk or Ipk of the input signal is less than 600 % of the range at the following
level.
The selected automatic range may change when the input waveform
is a pulse waveform of uncertain cycle. In this case, the fixed range
should be selected.
3.3
Measurement Interval
The time for acquisition of sampling data is determined by the measurement interval during measurement. The
measurement interval is determined by the data updating rate and synchronization source. The synchronization
source provides reference signals for measurement, and the data updating rate determines the updating cycle of
sampling data.
Measurement interval
The measurement interval is determined by the data updating rate and synchronization source. (see section
3.4
for
specific settings)
•
Synchronization
BK5335C adopts the frequency measurement circuit to test the input signal cycle set in the measurement
interval. The measurement interval is the integer times of the test cycle. The measured value of BK5335C is
calculated by averaging sampling data in the measurement interval. The reference input signal used for
defining the input signal measurement interval is called the synchronization source.
•
Measurement interval for conventional measurement
–
The measurement interval of the reference input signal is the time from the starting part of the rising
slope (or descending slope) through the zero point (intermediate value of amplitude) to the ending
point of the rising slope (or descending slope) through the zero point (intermediate value of
amplitude). However, the measurement interval which determines the maximum voltage or current is
within the overall data updating cycle. Therefore, the measurement of Ipk+, Ipk-, Upk+, Upk-, Ucf and
Icf calculated based on the maximum voltage and current also adopts the data updating cycle as the
measurement interval.
–
The rising or descending edge is selected automatically to prolong the measurement interval.
–
If there is only one or no rising slope or descending slope within the data updating cycle, the data
updating cycle is taken as the measurement interval.
–
The input signal to be used as the synchronization source can be set in each unit (for synchronization
with the zero point of that input signal). The overall interval of the signal voltage, current or data
updating cycle can be selected as the synchronization source for measurement.
