plotting data with different "densities"

[hamilton@terrasurv.com]

I have periodic readings of a device, usually taken one to many days apart. Here are the times so far:
3/15/10 19:09
3/23/10 7:43
3/31/10 8:45
4/1/10 8:05
4/2/10 8:44
4/5/10 8:13
4/6/10 8:10
4/9/10 8:47
4/17/10 9:38
4/20/10 18:07
4/23/10 7:42
5/2/10 12:00
5/11/10 21:37
5/13/10 22:18
5/15/10 15:43
5/21/10 10:05
5/24/10 11:38
5/27/10 8:43
5/28/10 7:46


I have the data in excel, and the data plots exactly as I want, dates properly spaced on the x axis, and the readings on the Y. There are two channels, so it makes two lines on the graph. Works well.

Now, I would like to add daily average air temperature readings. These would have an entry for every day rather than just the discrete dates/times that the other readings were taken on, and of course the scale would be different.

What is the best way to do this? The temeprature scale would be on the right, the other scale on the left, as it is now.

[DPlotAdmin]

Use Options>Multiple Axes. Under "Y Axis Options" select "Independent Y2". Under "Curve" select your temperature data, and under "Axis" select Y2.