BGA Rework Station Profile - Advanced

Altec PC410 gives you different temperature reading, It is because the wiring from the connector to the controller.
When the controller heats up it slides also, so it is important to use external TC meter.
When you have timed how long it takes to preheat using bottom IR only to the temp you are aiming at.
Then you use the altec pc410 sr232 and the software to look how good your temperature curve is.

If the curve looks bad you can smooth it by using the lower hotair.
You can start using top ir when you hit 160C top of the pcb this smooth temperatures.

But the key thing that you forgot to tell is that the controllers TC are in different places.
Bottom heater IR temperature is controlled over the IR plates this is why you need to set it higher.
Because it is not the PCB temperature it is reflective heat/radiation from the ir elements.
When the controlling is done like this you also need to tweak PID setting in the temp area where you like to rework. 
This is easy to do make the PID output led blink constantly when you are in the set temp.
It does not matter if the temp slides as long you have constant output.

Top ir is controlled by your TC touching the PCB so this is the real “chip” temperature.
So this is why you need to use ramp 1 that you don’t burn the chip keeping the radiation on too long.

The bottom Hotair is controlled from air flow so if you want same temperature what is in your preheter is giving you measure temperature
from bottom of the pcb above the ir plates and same time under the chip where is the hot air nozzle. Using two TC sensors.

When you set bottom hot air to 222C it is actually 222C in the bottom of the pcb. It depends how close your nozzle is.
When preheating the pcb keep in mind that the bottom nozzle is blowing could air in the bottom, if it is set to zero... could air hmmm 30c air haha desert man.

But really good basic information and I know if beginners do like you
they will succeed at the first try. Great beginners tutorial M8 10+