How do companies that make measuring tools like rulers make sure the product is accurate? Is there a universally ruler that is used to check? How do they make sure the measurements are exact?

Question

How do companies that make measuring tools like rulers make sure the product is accurate? Is there a universally ruler that is used to check? How do they make sure the measurements are exact?

In: Engineering

Answer 1

This is one of those vides I accidentally clicked on and ended up watching in its entirety:

[https://www.youtube.com/watch?v=gNRnrn5DE58&ab_channel=MachineThinking](https://www.youtube.com/watch?v=gNRnrn5DE58&ab_channel=MachineThinking)