After collecting data and creating a Heat Penetration file, you can evaluate multiple HP files along with the current file you have open.
To do this, go to the "Ball Plotting" section on the HP file screen and click "Ball Summary." The HP File Ball Summary page (pop-up) is then shown.
On the Ball Summary pop-up, click "Evaluate Multiple Files" to create a new ProCAL record and go right to the 1st tab of the Process Calculation page, the "Ball Summary" tab.
To add more files, simply select "Add Files" and choose the HP files you would like to add to this ProCAL record. To calculate the process after all files have been loaded in, click "Calculate Process" at the bottom of the ProCAL page. You will then be brought to the the "Calculate Process" tab (the 2nd tab within Process Calculation).