Hey Ed, is zeroing your gauges calibrating them?

In this edition of "Hey Ed," Ed discusses how zeroing your gauges is not the same as calibrating them.

Hey Ed, is zeroing your gauges calibrating them? This is a question that I have addressed for years as I’ve been sharing my knowledge about this topic for a long time. I’ve heard people say that when you zero your gauges, you’re calibrating them. And I’m simply going to say that’s not true. If you had an analog set of gauges and you took the cover off and took a little screwdriver and set the needle at zero, you’re zeroing it. If you want to calibrate a gauge, you’re going to take that same manifold and hook it up to a pressure that is known at a specific temperature. And then you would take and put that needle with that screwdriver at that specific temperature that corresponds with the pressure of the refrigerant that you would be using. And that’s the way I see it.