Is possible to detect or scan the computers without Sophos antivirus in my network?

Hi, 

You can achieve this after the deployment of the endpoint on your environment, you can manually match your system counts over the list of endpoints registered over Sophos central and export them as CSV file them match it to your inventory list.

Hi, 

You can achieve this after the deployment of the endpoint on your environment, you can manually match your system counts over the list of endpoints registered over Sophos central and export them as CSV file them match it to your inventory list.

Thanks, just manual process? Is possible make it with a tool that could scan the network and make the match with Sophos Central?

The new AD Sync has the IMPORT DEVICE Feature from AD.
If all PCs are on the AD then same list can be imported to Sophos via the tools. The one with agent not installed would be part of the un managed computers.
Answer to your questions--> Specifically there is no tool\feature via sophos to run a device discovery and auto add to SC