Fire Box temp with Propane

[arcpw]

If your fire box reds 225 is it safe to say that the heat temp in the cooking part will be 225? I saw this youtube video. How could I control the temp of the propane?

 

[sqwib]

If your fire box reds 225 is it safe to say that the heat temp in the cooking part will be 225?

no it would be less

I saw this youtube video. How could I control the temp of the propane?

with the regulator control knob