Newbie Rigol DS1050E Question

[Veramacor]

Fellow Rigol owners,  or experienced O-scopers for that matter,

I've been trying to zoom in on a 9-Volt battery signal's noise recently.  No problem aquiring the signal (around 7.8 volts).

The problem I have is when I attempt zoom in on the DC signal, by using the vertical scale knob down to say 100mv/Div,  I cannot re-center the 7.8 V signal on the screen as I have reached the scale limit.

Is there a way to reference the 7.8V signal on the center of the screen without the vertical scaler repositioning the signal?

I'll try to explain again later if I'm making myself unclear,

J

[Zero999]

You should use the AC coupling function to view an AC signal suppressed on a DC signal.

To measure DC you should use a DVM which is more accurate at DC.

[Veramacor]

Thanks that was a bit of a stumbling block!

V

[Simon]

to be honest your going to see more internal scope noise than the noise on a 7.8 power line so if it looks nasty: don't worry