I have a data set that consists of pressure readings taken over time for two
rooms. The readings range from -2.5 to +2.5. I want to develop a chart that
has each rooms reading represented by a different line. The y axis would be
pressure and the x axis would be time. I know, sounds simple. However, the
times are not consistent across the data sets...the pressure readings were
taken based on a change of value rather than a designated time interval.

If anyone knows how I can do this I would greatly appreciate the assistance.
I need to do this for approximately 50 different room combinations...so the
easier the better :)