All other parameters worked, but not the pressure measurement.
There is no documentation or user guide for this application. I have accessed the official website, but nothing could be found. I recommend checking the built-in Help section of the software or go to the installation directory and look for PDF or CHM files. Developers usually place valuable information in those type of files.
Or you could contact the developers about this inquiry: http://www.gyrotools.com/gt-contact.html