Freezer sensor disables and grabs outside temp under -19C - how to "fix"?

Configuration
1

As in the title, I have a temp sensor with an external probe that handles down to -19C. The thing is: when it’s under that temperature, it disables, making the device use the default external temperature - thus, my freezer suddenly seems to jump from -18 to 25C lol

What are good ways to handle that? I guess a template would help, but not sure? My rough idea was to consider the last measured temp if the difference between it and the current one is more than 20C at once…

Thanks for any guidance!

2

That’s a possibility, but how would it then react to the next update from “25” to “25.1”?

What sensor is this? I note that -18°C is 0°F — I wonder if there’s some sort of conversion failure going on?

3

Funny, you seemed almost right on the 0F guess, but given its specs it works up to -2F. I don’t think it’s a conversion issue, it’s stated in the sensor details its working range:
image

My rough idea is as follows, see if this is clearer:

  • temp changes from -17 to -18: stays at -18
  • temp changes from -18 to 28: stays at -18
  • temp changes from 28 to 28.5: the comparison is made against the currently selected temp, not the one in the device; thus, the comparison is from -18 to 28.5, and it stays at -18.
  • temp changes from 28.5 to -17: gets back to -17 since it’s around -18.

It’s this sensor, btw.
image

4

I’d try that with a trigger-based template sensor, and set a mode attribute depending on whether we’re giving real measurements or faked ones. Have a shot at that with reference to the docs and come back if you need more help.

An alternative would be an automation to update an input_number helper showing the corrected temperature; and an input_boolean for the mode.