EDF is a (UTF-8 encoded) plain text file modeled after the CSV data exchange format. It is an internally standardized measurement data format at Sensirion. You can recognize them by the file ending: mydatafile.edf. If you use the newest version of Sensirion ControlCenter all data will be logged in EDF files (see www.sensirion.com/controlcenter).

When ignoring the first few metadata lines that are all prefixed with the hash character (#), the EDF format is fully compatible with CSV files using the <tab> column separator. Sensirion ControlCenter logs all data as EDF files.
For CSV see https://en.wikipedia.org/wiki/Comma-separated_values

Since EDF files are text files, they can be opened and viewed with any text editor. If you installed the latest version of Sensirion ControlCenter on a Windows PC double-clicking EDF files will open it in Microsoft Excel, provided that Microsoft Excel is installed.

Most data analytics programs that support CSV files will be able to open or import EDF files when treated as CSV files. In some cases, it might be necessary to change the file ending from .edf to .csv and/or the header lines that are prefixed with the hash character (#) must be removed using a text editor. It is advisable to keep a backup of the original file before performing those changes.

When opening EDF files with Microsoft Excel the data should be displayed in a meaningful way, similar to the textual representation of the file. However, in some cases related to regional/locale settings, Microsoft Excel misinterprets the data. If your data looks like this it is most likely due to Excel misinterpreting the decimal separator. EDF always uses the dot (.) character as decimal separator, which may have a different meaning in your regional settings. E.g. If your regional settings use the dot (.) character as thousands-separator, the textual value  "24.3202" (corresponding to a temperature of roughly 24°C degrees centigrade) will be misinterpreted as 24_320_200. This can be seen here.

There are several solutions to this particular problem:

• Solution 1: Import the EDF file with the Text Import Wizard. This solution will only affect the file you import but not any other files.
  ◦ Under the advanced option, you can enter "." for decimal separator and some other symbol for the thousands separator. The thousands separator doesn't matter because it is not used in EDF files. Just make sure that it is different from the decimal separator.
  ◦ For more information see the full description of the text import wizard on the official Microsoft Office support website.
• Solution 2: Change the settings for all Excel files.
  This affects all Excel files but not any other office products.
  ◦ Follow the step-by-step solution on the official Microsoft Office support page or office tooltips.
• Solution 3: Change the system settings.
  This changes the system default and, in turn, all applications that use the system default, e.g. Excel, Word or any other program that might rely on it.
  ◦ Follow the step by step solution on office tooltips.