User`s guide
194   
Using the Oscilloscope
The Scope Auto Measure Menu
Preshoot and Overshoot . Preshoot and Overshoot measure the 
perturbation on a waveform above or below the top and base voltages 
(see the "Top and Base Voltages" section earlier in this chapter). These 
measurements use all data displayed on the screen; therefore, it is very 
important that only the data of interest be displayed. If you want to 
measure preshoot and overshoot on one edge of a waveform, then only 
display that edge. If you want to measure the maximum preshoot and 
overshoot on a waveform, then display several cycles of the waveform. 
Preshoot is a perturbation before a rising or a falling edge and is 
measured as a percentage of the top-base voltage.
Overshoot is a perturbation after a rising or a falling edge and it is 
measured as a percentage of the top-base voltage.
If the measured edge is rising, then 
Preshoot =
and,
Overshoot=
If the measured edge is falling, then
Preshoot=
and,
Overshoot=
V
base
V
minimum
-()
V
top
V
base
-()
-------------------------------------------------
100×
V
maximum
V
top
-()
V
top
V
base
-()
-----------------------------------------------
100×
V
maximum
V
top
-()
V
top
V
base
-()
-----------------------------------------------
100×
V
base
V
minimum
-()
V
top
V
base
-()
-------------------------------------------------
100×










