That is why a company must see the importance of gage calibration, they should see this as an investment, or as a discipline that is needed to be done for their quality assurances. If you think of it clearly, it's just like maintenance, everything needs to be maintained for a better performance just like a Gage Calibration, it's a process that must be done regularly.
A Gage calibration process is more than just a simple adjustment, as a matter of fact sets of test must be done in order to make sure the accuracy of the measurement is to the international standard, it is done by measuring a standard master artifact, in other words equally tracing an artifact in the National Institute of Standards and Technology.
Gage users can do their own gage calibration process by setting up their own laboratory and perform the process, in which is what we call in-house, or they can send it to a professional company which is trusted to do this calibrating service for them, or they could just return it back to the manufacturer for calibration services.
Gage owners or users usually use these three types of calibrating services, because calibrating process is not a quick one it takes time of at least three to six weeks before it is done. That is why It is wise to build your own In-house laboratory for your gage calibration, you would only need to invest on few facilities, equipments and trained personnel to do this, but in return you get a lower processing cost and faster turn around time.