I'm using a line chart that has 5 columns and 100's of rows to display time
and temperature for a coffee roaster. Time & temp data is measured by
digital probes (etc.), which is imported into a spreadsheet. There's a
temperature reading for every second so I can end up with up to a 1000 rows
of data for a 16-17 minute roast.

The Y axis is Temperature. The minimum value is 150 degrees with a maximum
of 475 and has a 25 degree scale.

Column A is where I enter a value of 00:00, 00:30, 1:00, 1:30, etc... up to
17 and this is used for the X axis labels. Column B (Series A) is where
I'll enter a dozen or more temperatures along the time line and is used to
display a desired profile. Columns C & D is the imported data showing bean
(Series B) and ambient (Series C) temperatures in the drum.

During the roast, temperatures are monitored and gas pressure is regulated
to increase or decrease the heat. The reading on the pressure gauge is what
I need to show along the Series B line so I can observe the effects of the
gas adjustments to the roast. The values I'm recording range anywhere from
1 - 12 and are entered into column E at whatever point in time the
adjustment was made.

I can't plot it as a series because the values are to small for the Y axis,
and text boxes would be to labor intensive. Is this possible?

Thanks,
David