When you use a AIR-INSITE 'Moisture' data logger the moisture dew point plotted in Graph Wizard is an atmospheric dew point value.

If you want to know the pressure dew point at the 'line pressure' where the dew point sensor was installed and 'you know' what this line pressure was, download and use the attached Dewpoint_calc.exe tool.  The tool is intended to assist in easily converting an 'atmospheric dew point' value into a 'pressure dew point' value.