Why the difference in temp display?

[Karsten]

Why is there a difference in the displayed temperature of the coil between the large displayed temp (the actual temp I've got it set to) that, once fire is pressed, starts at 0F and goes up to 430F and the 'Last Temperature' (the smaller one on the lower left) reading?

[Spirometry]

"Last Temperature" is the average temp of the entire last puff.

[Karsten]

Ahh!! 

Thanks!