I saw a few of these inside the Morgan Library and Museum (in NYC). I'm guessing it is measuring temp and humidity and reporting it remotely. I was wondering if anyone recognizes it?
Here's a different one sitting below one of the museum's three Gutenberg Bibles (dating to 1455; about 180 were produced). This one's battery looked a little swollen.
Not sure of the exact model but it looks like a temperature and humidity logger (as you thought). I was surprised by how expensive they can get and that most I saw could not report data back remotely (likely a power thing as most that did used WiFi).