Lame. They are just measuring the pressure, which is a poor indication of the state of charge since it varies as a function of temperature and humidity. You might get it to sort of work, but it will not be optimal.
I don't claim to be an AC expert, but to really do it right, you need to purge the system and then charge with a scale (by weight).
There are also high/low pressure charts (if your car manufacturer has them) as a function of temp/humidity that will get you close, but weight is the preferred method.
__________________
Jeff S
'14 991.1 Carrera S Coupe
'25 Cayenne E-Hybrid
'11 997.2 Carrera S Cab
'09 987.2 Cayman S
'05.5 Audi S4
'25 GMC Yukon XL
'17 718 Boxster
'18 718 Cayman x 2
|