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Slow signal (<1Hz) display

Posted: September 21st, 2017, 3:19 pm
by swr999
My question needs a little background, I apologize for this in advance.

I have slowly changing signals typically in the 0.1 - 1 Hz which I want to observe on a scope. I'm measuring things like slowly-changing temperatures.
When making any change on the scope front panel while observing slow signals here are the 3 types of scope responses I've observed:

1. The scope screen freezes for 6-12 seconds before it "comes alive" again and shows the moving trace. I have observed this behavior in a Rigol 1054Z and Keysight DSO-1002A.
2. Scope clears the screen and immediately starts a new trace from the edge of the screen. But no 6-12 second dead time. I see this behavior in an Instek GDS-2104E and an Instek GDS-1054B.
3. Scope immediately performs the front panel setting you made and simply carries on with the display at the new setting: No 6-12 second dead time, no blanking and restart of the trace. Just keeps going. This is the best behavior of course, and I see this on a Tek DPO-3034 and Tek TDS-2012.

My Question is: How do I refer to this behavior, that is, what do I call it? If I'm talking with an apps engineer at an instrument company and I want to know if their scope handles this scenario (slow signal display) according to options 1, 2, or 3 above, what do I ask??

I've searched oscilloscope forums and I don't see this feature of scope operation addressed. Is this addressed in the spec sheet for a scope? What do I look for? I know most folks don't care much about how well a scope goes slow; we want them to go fast, right? ;-) But I would appreciate if anyone could point me to where I can find some answers...

Thanks all, and again sorry for the long-windedness.
-Steve