Leading-Edge Pulse Time And Pulse Decay Time; Phase Measurement In Xy Display Mode - Metrix Multimetrix X 4010 Bedienungsanleitung

6.2.3.

Leading-edge pulse time and pulse decay time

According to the general definition, the leading-edge time "Tm" and the decay time "Td" of a square
signal correspond to the time taken by this signal to go from 10% to 90% of its amplitude.
1. Using the VOLTS/DIV. [8] and VOLT VAR. [7] controls, display the signal on exactly 5 vertical
divisions.
2. Adjust the vertical position with POSITION [6] so that the top level of the pulse coincides with the
theoretical 100% level located at +2.5 divisions, with the bottom level coinciding with the 0% at -2.5
divisions (figure 6).
3. Increase the time base speed to the maximum with [13], while keeping a leading edge on the s
screen.
4. Using +/- [16], switch if necessary from the rising edge to the falling edge.
5. Displace the trace horizontally with POSITION [12] so that the edge passes exactly through point
A, the intersection of a vertical axis and the horizontal line located at -2 divisions.
6. Since point B is the point of intersection between the signal edge and the horizontal line located at
+2 divisions, the formula giving the leading-edge pulse time is as follows:
"Tm" or "Td" time = Horizontal Distance AB (div.) x Time Base Value (t/div.).
Thus, for the example presented in figure 7:
Tm = 2.4 div. x 1µs/div. = 2.4µs
6.2.4.

Phase measurement in XY display mode

On a two-curve oscilloscope, phase measurement can be performed using the display of the two
curves, as shown in figure 7.
On this single-channel instrument, it can nevertheless be measured using the XY mode.
The formula for calculating the dephasing j is then as follows:
Sinϕ = AB / CD, so ϕ = arcsin AB / CD
Thus, for the figure shown in illustration 8:
AB = 3.5 div. and CD = 5 div., so Sinϕ = 0.7 , which means ϕ = 45°
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