The same as the 765 except the RH sensor has been replaced by a thermal infrared sensor.
The 775C (with logging) is the same as 775 with data logging capacity for over 70,000 readings of all 4 parameters.
No special software is required, logged information is stored on an internal USB Flash disc and the data can be downloaded onto a PC and viewed with any spreadsheet (Excel etc)
A free application (RView) is also available for download that displays the data as a zoomable graph that can be saved as an image for inclusion in documents and/or printed.