If the temperature for a PhysioTel Digital implant is 19.83 C, this is generally because the implant signal has dropped out - is out of range. When the implant comes back into range, the temperature signal will return to expected values.
DSI recommends analyzing the dataset using the Rail Detection setting under the Noise tab of the Temperature Analysis Attributes. This will replace the value with NaN (not a number). It will display as a 0 during acquisition; however, the 0 will not be averaged into the reported data.
If rail detection is not used, please understand that the value of 19.83 will be averaged into the temperature data for that logging period, causing inaccurate derived data until those sections are marked with Bad Data Marks.