I have collected two data points for 18 months, 24/7. Puts that at 157K.
That is Station 1 & Station 2, date, time, reading1, reading 2.
When I went to chart in Excel got the message that the width was limited to
255 in the chart.

Any suggestion on how to display the data?

XP, XL 2003.

Thanks,

Gregor