Several years back, I was asked this question: Does measurement software have the ability to determine scale without the use of scale bars? On numerous occasions in a variety of ambient conditions, I have tested and compared the results of initially setting up a system using temperature/material software compensation. Next, I would check the accuracy by measuring a NIST traceable scale bar (length adjusted for ambient temp). Most of the time, the results compared within  0.0005 in. – 0.0015 in. So here is the million dollar question. Which one is truly correct?

Most likely neither. Swearing by either one as “metrology law” is most likely grounds for an argument.

Second question: Is either one sufficient to use with confidence? Probably yes. After all, this is done on a daily basis. Currently, I am unaware of any in-depth scientific studies comparing the two methods. Each method has its pros and cons, and the variables seem endless when everything is taken into consideration and factored into the “equation.”

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