Looking for an EMI/RFI diagnostic tool

[cbsix]

Hi everyone. My first post here.
I work on CNC plasma cutting machines and occasionally face some difficult to diagnose faults. These faults often caused by EMI/RFI as a result of poor grounding or shielding.

I was wondering if an oscilloscope could be considered as a handy tool to diagnose these types of faults. If yes, what would be the minimum specs that you would recommend? A cheap USB oscilloscope, such as Hantek 6022BE or Owon VDS1022 suitable for this purpose?

My knowledge in electronics fairly limited and I don't think I will be needing these oscilloscopes for any other purpose.
I would appreciate any help to point me in the right direction. Thanks in advance.

[bob91343]

No simple answer.  EMI is caused by either conducted or radiated noise.  You need to figure out which it is.  In many cases it's both.

Filtering and shielding are the two basic methods of reducing this interference.

[uski]

I had to diagnose EMC issues and it is a specialty field in itself.
You cannot expect to buy a magic instrument which will fix your issue, you cannot buy a solution, you need to acquire the knowledge to diagnose the issue.

What type of issues are you exactly experiencing ? A board resetting ? RF communication issues ? EMC certification problems ? So many things can go wrong and the causes can be so different that it's very difficult to give you any valuable answer without knowing more.

[cmumford]

Made me thing of this:

[David Hess]

I would consider a digital storage oscilloscope with a high voltage differential probe to be very useful for tracking down faults caused by EMI/RFI.  Alternatively, a DSO with isolated inputs may be even more suitable because of its usefulness in power applications.

Note however that it takes knowledge and experience to make the most of any instrument in EMI/RFI applications.