So I have this old Wika brand dial PSI gauge, looks like it was put together in a shop out of generic housing and fittings with Wika internals. Well, the needle rested at about 3-4 PSI instead of 0 for years, so I never used it. Today I opened it up to see why, found that there is a crescent shaped bar which is soldered into the pressure tube which actuated the mechanical gearing for the needle. Well, some very gentle pressure on this crescent shaped bar and the gauge is now resting and 1psi (still not zero but whatever). It reads 1.5 PSI lower than the random cheap-o stick air gauge I compared it to (read 34.5 PSI, other read 36 PSI). Did I screw up the calibration, improve the calibration or just change the tare/zero without affecting calibration?
