Hi everyone .
I have a rigol DS1202z-e oscilloscope
lately I have to make alternating current voltage measurements but the PP voltage to be measured is very small, it is in the order of mV.
the disturbing signal overlaps and mixes on the screen with the small signal that I am interested in measuring and displaying.
Is it possible to eliminate the disturbing signal from the screen?.
1. Make sure 20 MHz bandwidth limit is switched on.
2. O-scopes in general are not good for accurate measuring low signals.
You may use AC milivoltmeter for accurate AC voltage measurements (average voltage or RMS but not Peak-to-Peak). Oscilloscopes are more for observing signals but not for measuring.
But there are new 12-14 bit digital scopes which I guess are better with this (with what you want).
As for me, I use o-scope together with AC millivoltmeter, AC microvoltmeter and a very good soundcard (as spectrum analyser) to make low-noise measurements and research.
Ciao arivel,
your signal is too weak, so make it bigger ((pre-)amplify).
You can also try to filter out the noise (bandpass-filter on your signal).
What probe / shunt are you useing?
Where is the noise comming from?
Good luck
use the averaging mode instead of normal acquisition
This. If the "desired" signal is deterministic and the noise is randomly distributed, averaging might help (a lot).
Most scopes (even my old analog Hameg scope) support averaging, so it's a cheap and easy thing to try.
thanks for the replies.
the probe is the one supplied with the oscilloscope, nothing esoteric.
in my opinion the noise is that of the electrical supply (room wiring 50 Hz 220 volts) and the circuit that I have to analyze most likely functions as an antenna.
Maybe it's better to explain what it is. I should have done it right away. I attach image.
it is an AC current sensor that detects a voltage by induction of the current flowing in a piece of linear conductor (rogovsky coil variant).