Change popBody Text at runtime?

For a current project I use a number of JQuery Mobile ToolTips where I change the text that pops up at runtime. To get rid of JQuery Mobile controls I was going to add a button configured with a popOver and popBody text.

Is there a way to change the popBody text at runtime?

My situation is that for my application my user can select different units (deg F, deg Celcius, psia, Kpa, Bar, etc) and I customize the TootlTip text based on what they have selected.

e.g.

Pressure entered is too high. Needs to be between x and y psia!

Regards,

Bob