# Compute the measurement of the oscilloscope

Discussion in 'Homework Help' started by SilverKing, Jul 4, 2015.

1. ### SilverKing Thread Starter Member

Feb 2, 2014
72
0
Hi everyone.

I've a problem I need help to solve it. The problem states:
"An instrument (oscilloscope) is prepared to measure a sinusoidal periodic wave, compute the measurement error if the same instrument is used to measure the wave indicated in figure 1

(The wave is much more like a sawtooth wave, sorry for bad drawing)

Actually, I don't how to start, should I assume that sinusoidal wave is 4V peak (from 6V to 10V above, and 6V to 2V below) and substracting the values?

2. ### Hypatia's Protege Distinguished Member

Mar 1, 2015
3,080
1,839
What characteristic of the signal are you measuring? Distortion (and, hence, 'error') will be a function of the instrument's input bandwidth and sweep linearity -- neither of which are stipulated in the 'problem'...

Best regards
HP

3. ### WBahn Moderator

Mar 31, 2012
20,228
5,755
What does it mean to "prepare an oscilloscope to measure a sinusoidal wave"?

What does it mean to "measure" a waveform?

4. ### SilverKing Thread Starter Member

Feb 2, 2014
72
0
It turns out that the solution lies in the 'k' factor - which Vrms over Vavg -, and every oscilloscope is designed with k equal to 1.11 (sinusoidal wave 0.707/0.632), so to solve this problem, I've to determine both the Vrms and the Vavg of the triangular wave and compute the error with respect to the default k (1.11).

5. ### WBahn Moderator

Mar 31, 2012
20,228
5,755
This makes even less sense than the rest of the problem description you've provided. For a sinusoidal waveform Vavg is identically zero, making your 'k' value infinite.