Offset On Oscillosope

[Bob K]

I have set up the AWG for a 15 Khz sine wave, 1V peak, 0 V offset.  I connected that to the DC input of the Scope 1 and it shows a 100mV offset.  In fact, if I go under "Measure Vertical, Average" it says -145mV, so it is real.

 

The problem also persists if I AC couple the scope, except then the offset measures -55mV

 

Is the an error with the Digilent product?  I had a student in my class have this same exact issue.  

 

Please advise ASAP.

[attila]

The devices are calibrated during factory test, but with time/wear re-calibration might be needed.

 

This can be performed using the Calibration Wizard opened from WaveForms main window, Device/Manager, after selecting "Show advanced features", with the Calibrate button.

 

Before calibrating the Scope, first calibrate the AWG1 for ADiscovery and Ref1 for EExplorer. For AWG/Ref calibration a 4 digit voltmeter is needed.

 

For better precision, before calibration keep the device connected with the application for a few minutes to reach its normal operation temperature. 

[Bob K]

That did it, Attila.  Thanks.

 

FYI, for other users, I had only used this board once before for about an hour. I had not noticed at that time it was not calibrated, so not sure if it came from the factory uncalibrated or something went off.  But anyway, seems to be fine once calibrated.  

[attila]

Good to know that your problem is solved.

 

Each device is tested/calibrated in factory and at the same time programmed. Without this it would not be recognized by WaveForms.

For better precision the device can be re-calibrated.