This is the logger you need for monitoring a fridge or freezer.
These sturdy loggers sit (or hang) in your fridge or freezer measuring temperatures and automatically transmit their readings to the gateway.
They never need to be taken out of the fridge or connected to a computer to get you results.
The loggers are accurate to half a degree.
If the power goes out or internet connection is lost, the logger will store data (for weeks and weeks if necessary) and transmit it to the gateway when it comes back online.