LogTag Temperature Recorders

Why does my LogTag say -40°C?


Help! My LogTag says it hit -40°

If you retrieve the temperature data from your LogTag and you see a reading of -40°C, don’t panic. This is just the LogTag’s way of telling you it couldn’t take its normal temperature sample. Your refrigerator didn’t get that low.


-40°C What Happened?

So what happened?

The LogTag took a reading  and could not find a connection to the probe (see image on the right). 

If your LogTag is disconnected from the probe, during a scheduled reading, it will log as -40°C rather than the actual temperature inside the environment. 

So how can I avoid this?

The design of your specific LogTag means it needs to be connected to a probe to ensure every recording is true of the environment it is monitoring.

When doing a download, this can cause an -40°C reading to occur, as your LogTag is away from the probe. 

What you must do to reduce the occurrence of these -40°C readings is

  1. Ensure your LogTag Software (Analyzer) is open and ready to be used.
  2. Pres the ‘Start/Mark’ button (once) and disconnect your LogTag from the probe.
  3. Insert your LogTag into your reader (cradle).
  4. Once your data appears on the screen, take out your LogTag from the reader immediately and re-connect it to the probe – ensuring the probe is securely inserted into the LogTag’s brass attachment point.

By following these steps, your LogTag is only away from the fridge for, ideally, 30 seconds. This will minimise the -40°C readings appearing on your reports. 



If this -40°C consistently appears on your reports and you know your LogTag is not being left out from the probe, then it could mean you have an issue with either the probe or Logger. 

You can call the support team if you require further insight into this matter, on 1300 08 20 20.