FNIRSI-1013D "100MHz" tablet oscilloscope

[Atlan]

First, it is necessary to have the input divider calibrated.  After switching on the oscilloscope, wait 3 minutes, perform base calibration.  And after turn on ONE channels of DC mod and measurement, bring a suitable signal to input. (eg rectangle or sine 5V peak to peak and 2.5V offset), press auto button. The option "dc shift calibration" is activated in the diagnostic menu. In the oscilloscope mode, the CTRL key is pressed. The menu to the right allows you to change the value of dc_shift_center, place the signal in the center. (You can check whether the signal is in the center using the cursors.)
The default value is 112, decreasing the value moves the signal up, increasing the value moves the signal down.
Change the value, press the CTRL button, press AUTOSET, the change of signal location will be reflected. If the signal is not placed symmetrically on the central axis. Repeat the whole process.
Then disconnect the signal from the oscilloscope!!!
With a value of 2, set the straight signal line to coincide with the channel cursor.
With a value of 3, set so that the value of Vmin = 0mV
Press end cal.

The option "dc shift calibration"  deactivated in the diagnostic menu.

[Magua]

With a value of 3, set so that the value of Vmin = 0mV


The value does not rise above 350!!! Therefore, -300 mv does not become less!

[Atlan]

The bottom image shows that the supplied signal does not have parameters that would require a DC shift.  Or the Auto set button was not pressed.  And with that, the oscilloscope didn't do things related to the DC shift.  I wrote a modified procedure where for values ​​2 and 3 it is necessary to disconnect the signal from the oscilloscope.  Limits management is probably needed.  I will upload the modified limits here tomorrow.

Other values ​​1 and 2. Do they have a sufficient range?  Don't they need to adjust the limits?

[Magua]

Other values ​​1 and 2. Do they have a sufficient range?

Yes, the limits are quite sufficient!

[Atlan]

try limit is 300 to 400

v0.025h

if I press END CALL, the recording goes to the sd card, and it is no longer possible to use RESTORE to restore older values ​​1-2-3

[Felipe Lacerda]

v0.025h

DC shift calibrate with sine 5V pkp 2.5V offset (1V/div scale)
parameter 1,2,3 OK 

but... noticed that when using scales below 1V (200mV/div) the cursor does not adjust to the center as in the 1V/div scale.
Is this what is expected?

I tried to calibrate with sine 1V pkp (200mV/div), but then the first parameter needs to be reduced to the lowest value (50) to center the cursor...
and this way the 2 parameters do not move the wave by any value, it does not work.

I hope my feedback is useful.