Hantek DSO5102P issue

[UnderTheRaid]

Hi I have two 5102's and they both do the same thing. If I press measure the scope mean v is pretty close until I put it on 10v per division and go above 20v by the time I get the 24v dc the scope reads 2v lower at 22v mean. On 5v per division its much closer 23.6v. Am I being stupid and have something weird set or has anyone else noticed this? is there a fix for it I had a search but didn't see anything. Like I said both my 5102p's are the same.

Thanks

Brian

[chinoy]

Just got of the phone with a friend and we were discussing the poor accuracy for low voltage readings on this scope. My application needs 0-1 volt accuracy off .1 volt at least.
BTW my unit landed up today. Unpacked it. Powered it on and it works. I got such a deal on it that I was afraid they would send me a dead unit.
Anyway he gave me a tip he said make sure your not using the probe in 10x mode. Make sure its set to 1x.
If that still does not work try with better quality probes.
When I spoke to the local Hanteck dealer about poor accuracy on voltage he said well buy a Siglent then. lol

I was going thru the user manual. Seems if there is a change in temp off 5c your calibration goes for a toss.
So the user manual says let the scope run for 30 min for the temps to stabilize. Then do the calibration.

Quoted from the user manual.

The self calibration routine helps optimize the oscilloscope signal path for maximum measurement
accuracy. You can run the routine at any time but should always run it if the ambient temperature
changes by 5℃ or more. For a more accurate calibration, please power on the oscilloscope and
wait for 20 minutes until it has adequately warmed up.