Ok! Thank you so much for your reply.

I have the PC Base oscilloscope 2205MSO. Now, I need to measure the scope of current in Automobile Electric system. Can I buy the Current Clamp PP264: 60 A AC/DC Current Clamp (BNC) and connect it to my oscilloscope 2205MSO.
Thank you for the help!

I have fixed the problem. Thank you so much Mr Martyn.

Thank you for reply me! I remember that when i buy the Picoscope, i have checked it and both of the channels got the 0V level very well. They displayed coincidentally very well, but i have gone wrong at channel B recently. 1/ I did both ways. The frist, I connect 2 ground clips at the same position ...

My oscilloscope has 2 channels, channel A and channel B. When i connect 2 probes in the channels and use them simultaneously, i see just the channel A can get the level 0V very well, but the channel B always remains nearly -0.6V. How can i correct the level of channel B to get the 0V. Please help me...

Ok! i will post latter. Thank alot!

Please help me to solve this problem. My Oscilloscope 2205 MSO have 2 channel Analog A and B, when i connect 2 probes to the oscilloscope simultaneously, the channel A gets the 0 Voltage very well but the level of channel B always remains nearly -0.6 Volt. How can i get the level 0V at channel B lik...