Tektronix TDS 644A Sprinkler User Manual


 
Appendix B: Algorithms
TDS 620A, 640A & 644A User Manual
AĆ17
3. From TLR, continue the search, looking for a crossing of HighRef. UpĆ
date TLR if subsequent LowRef crossings are found. If a HighRef crossĆ
ing is found, it becomes the high rise time or THR. (Use linear
interpolation if necessary.)
4. RiseTime = THR - TLR
High
HighRef
LowRef
Low
THRTLR
Rise Time
Figure AĆ3:ăRise Time
RMS:
Amplitude (voltage) measurement. The true Root Mean Square voltage.
If Start = End then RMS = the (interpolated) value at Waveform[Start].
Otherwise,
RMS =
ŕ
End
Start
Ă(Waveform(t))
2
dt
(End * Start) SampleInterval
Ǹ
For details of the integration algorithm, see below.
Integration Algorithm
The integration algorithm used by the digitizing oscilloscope is as follows:
ŕ
B
A
W(t)dt
is approximated by
ŕ
B
A
W
^
(t)dt
where: