When exporting data from a power chart the time interval changes based on the data range that you choose, if you choose a short date/time range then you get more granular results. If you select a longer date/time range then the interval also increases. Is there a way to export the data as the raw time stamps (not what seems to be a scale) from the database using the export feature in PowerChart?
Construct your own history query with the granularity desired, executed on a button press, then convert to CSV and deliver via system.perspective.download().