Error reading peak signal values

Forum for discussing PicoScope version 6 (non-automotive version)
Post Reply
User avatar
jane
Newbie
Posts: 0
Joined: Sat Mar 03, 2012 12:20 pm
Location: Norway

Error reading peak signal values

Post by jane » Tue Mar 27, 2012 6:43 pm

When I apply 142mV (100mV rms) from the internal signal generator to Ch A I do measure:
Amplitude at peak: -20.69 dBV
Average amplitude at peak: 74.2mV

Why do I read 74.2mV and not 92.4mV that is equal to -20.69 dBV?
And why not 100mV or 142mV (peak value)?

According to the Picoscope 6 users guide (Spectrum measurements):

Amplitude at peak.
The amplitude of the peak signal value.

Average amplitude at peak.
The amplitude of the peak signal value averaged over a number of captures.


In other words: "Average amplitude at peak" should be equal to "Amplitude at peak" when the stddev is close to zero..
avg-amp-peak.gif
PicoScope® 6 - PC Oscilloscope software version: 6.6.23.2
Copyright © 1995-2012, Pico Technology Ltd
Model: PicoScope 4262

Martyn
Site Admin
Site Admin
Posts: 3305
Joined: Fri Jun 10, 2011 8:15 am
Location: St. Neots

Re: Error reading peak signal values

Post by Martyn » Wed Mar 28, 2012 9:12 am

We are currently looking at the Picoscope 6 measurements for the 4262 as there may be a few inaccuracies with these.
Martyn
Technical Support Manager

Post Reply