noun
gauge pressure
Technical term in physics and engineering: pressure measured relative to ambient atmospheric pressure.
タイヤのゲージ圧力を測ってください。
Please measure the tire's gauge pressure.
絶対圧力 is absolute pressure (relative to a vacuum), while ゲージ圧力 is relative to atmospheric pressure.
Compound of ゲージ (gauge) and 圧力 (pressure).