Tektronix 540A Blood Glucose Meter User Manual


 
Reference
Waveform Differentiation
Advanced DSP Math
(optional on TDS 620A & TDS 640A), provides
wave-
form differentiation
that allows you to display a derivative math waveform that
indicates the instantaneous rate of change of the waveform acquired. Such
waveforms are used in the measurement of slew rate of amplifiers and in
educational applications. You can store and display a derivative math wave-
form in a reference memory, then use it as a source for another derivative
waveform. The result is the second derivative of the waveform that was first
differentiated.
The math waveform, derived from the sampled waveform, is computed based
on the following equation:
Where: X is the source waveform
Y is the derivative math waveform
T is the time between samples
Since the resultant math waveform is a derivative waveform, its vertical scale
is in volts/second (its horizontal scale is in seconds). The source signal is
differentiated over its entire record length; therefore, the math waveform
record length equals that of the source waveform.
To obtain a derivative math waveform:
1. Connect the waveform to the desired channel input and select that chan-
nel.
2. Adjust the vertical and horizontal scales and trigger the display (or press
AUTOSET).
3. Press MORE Math1, Math2, or Math3 (main) Change Math Defi-
nition (side) Single Wfm Math (main). See Figure 3-21.
4. Press Set Single Source to (side). Repeatedly press the same button
(or use the general purpose knob) until the channel source selected in
step 1 appears in the menu label.
Description
Operation