get a digital gauge. i've never had one in good working order be off by more than +/- 1psi. that being said, cheap, $10 or less / walmart gauges... dont stay in good working order long term, i've had one give wacky readings after being dropped about 4', and i've smoked one after getting it in water less than 1/4" deep
i've been using a matco DT100 gauge for about 2yrs now, been dropped, soaked and im sure ive checked over 1000 tires since ive had it and no trouble. only $28 on thier site
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