The scanner watch was a device used by Sarah Jane Smith to detect alien life, and identify the species and its origin. It gave off a humming sound when in use. Superficially, it appeared to be a normal wristwatch, but the face of the watch concealed a scanner screen. Like her sonic lipstick, it was left by the Tenth Doctor for Sarah Jane inside K9.
We like tracking our technology round these parts. Only problem is that the show is about a time travelling scientist. And he's spawned shows like Torchwood that are entirely focussed on alien tech. So there's a lot of tech sittin' around the joint. Be bold, though, and start your journey at category:technology.
When looking for a piece of technology on this wiki, it's helpful to think about some of the broader categories. Looking for the tech of a certain species? Go to technology by species.
The DWU likes its sonic tech, doesn't it? But it's not just the sonic screwdriver you have to keep an ear out for. Don't forget, the Ice Warriors and several other species are heavily invested in sonic technology, which you can find at category:sonic devices.
One of the broadest classifications of technology is communications technology. Since the series is about a guy who likes to talk a lot, we figure that only makes sense!