DS213 gain calibration

Volhott

Hi.

How do you calibrate the gain of a channel?

The K4+K3 combination calibrates the ground level.
Rotating the dial A while "CAL" option is selected will only shift the entire range, but doesn't change the gain.
Effectively, it is the same as ground level shifting.

The voltage measured are alwas off by some fixed value, and if I try to compensate it by rotating A dial with "CAL" option, I would also shift the zero.

What's the correct method of scope calibration using external voltage sources?

minidso

You use DS203 or DS213?
DS213 is auto calibrate, no need choice "CAL"

Volhott

It's DS213.

It does something when calibrating, but what's the procedure?
Shorting the probe? Connecting to own signal generator output?
Any ways to use external precise voltage source?

In any case, the measured values are always somewhat off from the known source voltage.
And performing auto calibration without correct procedure makes the next measurements even worse

minidso

The channel gain of the DS213 is fixed.
No calibration is required.
‘CAL’ is used when auto-calibration fails in extreme cases and is only used for zero calibration.

Volhott

Well, that's not really good.

My multimeter and lab PSU agree pretty well on the voltages. Say, 3.3 v selected. The DS213 measures 3.08v.
For 2.5v source DS213 measures 2.34v, and for 1.8v source DS213 measures 1.68v.
The observed scale is pretty much the same, ~0.9333

It's understandable that scaling the values for the waveform takes precious clock cycles, but at least the summary values shown in the bottom row (Vmax, Vmin, Vp-p,  /etc) could be scaled. They don't update very frequently, so scaling it wouldn't hurt the performance.

minidso

The next version will add a new feature (gain calibration for users to accurately measure voltage)
In addition, oscilloscope sampling is affected by input signal ripple, probe matching, etc. It is not recommended for accurate voltage measurement.

skumdog

Where is this new version? Not whats there now, I mean newer! This thing is being beat by a $40 scope on amazon. I know this beast has some potential but you guys seem to have given up on it, although you are still selling them by the truck loads!

minidso

Sorry, no timeline to make public。