Is an image created by Disk Utility sector-by-sector?

[winkosmosis]

I need to make a sector by sector mountable image file of a USB drive that will allow recovery of deleted files. I'm not looking to simply put every file into a DMG. Will the DMG created by Disk Utility copy all sectors, including empty ones? I've searched extensively and what I'm finding is a lot of posters on various forums saying to use DD or a program like Carbon Copy Cloner, which doesn't even allow you to create a sector-by-sector image file, only copy sectors from one disk to another. I've used DD before on Linux systems but I'd like to avoid it if a GUI tool does the same thing.

 

[winkosmosis]

I did the DMG creation process and the resulting DMG is as big as the USED space on the drive, so it apparently doesn't include empty sectors.

I tried DD and it quit after 50GB because apparently the drive was suddenly in use even though it was dismounted. But I've found that Disk Drill does create a sector by sector backup of the partition. I've been searching for days and only now found this program by specifically searching for "recover deleted files OSX". Somehow it never gets mentioned in forums when people are looking for imaging methods.