Help identify the purpose of a potentiometer

[dark_hawk]

Hi,

Hi. I have a Proskit SS-989B rework station. The hot air handle was old and broken so I replaced it with the Proskit handle model 9SS-900NB-HG which is supposedly for a different model. Problem is they are a bit different in regard to resistance of the heating element, and I need to calibrate the station.

Calibraion is done by two potentiometers, RH1 and RH2.
When I tweak RH1 is changes actual temperature of the air, RH2 changes also the temperature but by a lower margin per turn than RH1.

Question is, what is the purpose of RH2?

[MarkF]

What you have just described is coarse and fine adjustment.

Does RH1 happen to be five to ten times bigger than RH2?

Chances are, they are wired in series.

[dark_hawk]

What you have just described is coarse and fine adjustment.

Does RH1 happen to be five to ten times bigger than RH2?

Chances are, they are wired in series.

Thanks for the reply.

They are not in series. I've contacted the company and they replied at last, RH1 is temperature adjust and RH2 they call Amplifier and suggest to set to zero. Not sure what that one is doing exactly.