I checked the calibration on mine once using a syringe tee'd into the static line, Iirc 5000' was the highest altitude I could replicate the vacumn force needed to even simulate this mediocre altitude was quite an effort.
actually that raises a question....what material are thestatic lines when they enter the pressurised section of an airliner, they must be rather stoutly engineered so as not to collapse with the pressure differential, thick walled stainless tubing I guess or something similar
Actually now I think about it in this day and age they are probably electronic pressure sensors outside the pressure shell with just wires to feed the instruments coming inside...but they couldnt do that in the olden day of first generation jetliners