When I was in tech school I was told to never ever adjust the calibration on the gage set. Apparently it will ruin them. We were told to make note of how much they were out and make the adjustment in our heads.
My richie set was so much out on the high side that I had to adjust it. When I screw the plastic cover on the front it alters the reading and throws it out by 5 to 10 psi.
Is it common to have to adjust every day or so due to varying atmospheric pressures? Was he right should I just leave it? Is it common for the adjustment to go out simply by screwing back on the cover (pressure change?)
Is there a brand that is better quality?