Ironos: Unclear documentation on some things (temperature and voltage calibration)

[epigramx]

On temperature calibration: If we change VIN, do we have to recalibrate? When it calibrates, does it assume the room has a specific temperature? If yes, which one?

On voltage calibration: Is it required? What happens if one doesn't do it? It seems to be manually set only. Do we have to 'multimeter' our VIN and input it?

[Ralim]

Changing VIN doesn't matter.

It's mostly actually calibrating the 3.3V rail and the slight variation in the tips.

Voltage calibration is generally not required. A small number of units have poor tolerance resistors where it can matter, but I would say for 99% of people it's not required.

[epigramx]

And is temperature calibration always the same accuracy (if done correctly), or does it assume the room temperature is specific? e.g. If it assumes the literal room is 25C and in a 30C room it would be off by 5C.

[Ralim]

Should be same accuracy, so long as handle internal temp === room ambient temp.

[Sinclair-ZX81]

When is it best to run Calibrate temperature - immediately after powering on the iron (so the handle still is on room temp), or after some minutes, when the handle got standby operating temperature due to warm-up of internal electronics?

[Ralim]

immediately after powering on

Generally it should _not_ be required for most users