PCSU200 problem

I have a problem when using PCSU200. If I connect the probe to the generator output to messure, it gives me the wrong result. If I set the generator to be a square wave with 8V peak to peak the oscilloskcope shows some weird wave and messure the peak to peak to be 19.4mV. What do I do wrong? I have tried to use x10 and x1 with the probe but it makes no difference except that the peak to peak value gets differnt. I have also calibrated and messured the generated signal whit an other oscilloskope witch gives me the right result of the generated wave?

Does the oscilloscope show right values if you measure other sources e.g. some battery (1.5V) voltage?

I found out that the problem was the probe. It was new for the day so i didn’t think it would be the problem. However when I messure to ground the oscilloscope shows 130mV is there any way to manully calibrate the scope to show 0 when messure to ground? The automatic calibration dosen’t manage that?

Due to the 8bit ADC the resolution on 3V/div range is 90mV and on 1V/div range 30mV.
You may manually adjust the calibration by opening the PCSU200.ini file in a text editor (e.g. Notepad).
If you are using Windows Vista (or higher) the PCSU200.ini is located in the folder:
In Windows XP the file is located in the installation folder e.g.:
C:\Program Files\Velleman\PcLab200

In the PCSU200.ini locate the following lines:[Calibration] offs_1=112 offs_2=116 v5_offs1=-5 v5_offs2=0
In your case the values are different.
Changing the values of v5_offs1 and v5_offs2 you can affect the DC mean on the ranges 1V/div, 0.1V/div and 10mV/div.
Then save the PCSU200.ini and then run the PcLab200.