There certainly isn't the power/upgrade here, yet, for detecting Force affinity, but I was wondering, assuming there isn't a gizmo in the book, already, how one might manage a device that detects, or at least confirms, the presence of a Force-user. Being a more seedy, gray setting than the "average" Star Wars game, where the characters might be more down and dirty, or even helpful Imperial servants, they might make a living trying to find Force Sensitives, in order to hand them over the Empire, for a profit. Whoever comes to collect, whether local Stormtroopers, the 501st, some Inquisitor, or even DV, himself, might want a gizmo that confirms this is a "Jedi", to make it worth their expense to come all the way out to the OR, AND with cash to pay the captor.

So, how might this apparatus work? I'm not thinking of a ranged detector (stupid to me), but something like Qui-Gon uses in Phantom Menace, that could rate their potential.

The motive here is, I was thinking of a character of mine, and a story came into my head. The character is my young not-quite-a-Jedi Ender. In this story, he is caught by a down on his luck guy, who takes him home and calls the Empire. He has a young daughter, about Ender's age, who is none to keen on handing someone over to the Empire, just to get killed, and starts chatting with him. In the end, Ender suggests, based on something she said, that she might have that spark, too, and this thought terrifies her father; it's a lot different handing over a stranger to the Imps than the only family he has, and he doesn't know if Ender is just saying this to rattle him up, trying to save himself, or if he is being honest. In said story, they might run off, as a group, persued by the Empire. It's not a game I'm in/running, but I do see how it could be one. I could see where Dad might wish he had a gizmo, to tell if his daughter has anything to worry about, from the Imps who will show up soon, and I can also see the Imps having one, in the event Ender doesn't feel like putting on a show, to give his heritage away, before they pay out a bounty on him.

Maybe some kind of Medicine check that can tell the Force Rating of the "patient"?

Why not just use the one Qui Gon uses? Maybe it's a generic medical device that can be used for a number of purposes one of them being Midi-counts. Didn't seem like it would need any real medical training, at least from the movie.

The Emperor's forces actually used a Force Detector to aid in their hunt for rogue Jedi. If you've read the Jedi Academy trilogy, it's the device that Luke finds and has Lando use to help him find his first students.

Here's the Wookieepedia link.