Pass Labs Amplifier Meter meaning?


On a Pass Labs amplifier, what exactly does the meter measure?
tvad
Re "The meter is intended
as a general indicator of the status of the amplifier and has not been calibrated to reflect any
particular values"

Maybe EKG's would be just as useful if they simply showed that someone's heart is beating, without worrying about any particular "values."

Cheers,

cwlondon
Are the above ten year old responses still the same for the current X and XA point 8 models?