Take your tire gauges to a reputable commercial truck tire dealer and have them tested against their "master gauge". Our local dealer (Pomps Tire Service) requires all their employees to check their gauges against the master every Monday morning before starting work.
It's a free service they also offer to retail customers. I've had all my gauges tested several times. Over the last 10 years all of mine have remained accurate and haven't had any problems.
I have 2 like this:
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2 Like this:
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and 2 like this"
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