I have a Keysight U1282A here, the display shows 18.4 deg for the meter internal.
If I select the Temp mode for ext probe and short the test lead ... it shows 18.4 just as you explained
![Cheesy :D](https://www.eevblog.com/forum/Smileys/default/cheesy.gif)
So my question: Can an external probe show lower than the room temperature?
I mean this is 0 ohm when leads are shorted so it will be hard to get a negative ohm