When you say "what's a level...level to?", you would have to compare it to a standard reference somewhere. The bubble's gonna go where it wants to go inside
that cylinder; it's the 2 lines which say it's level to eyelevel. Those 2 lines must be set against a calibrated level which was calibrated against another..etc...all the way
to the master standard somewhere. All measurement devices have a master standard somewhere. There is a metric gram in a vacuum cylinder along with a metric meter stick in Europe which holds the International Standards group. I wonder if they have a level somewhere which stands for the standard level? If you want to find out more about standardization, do a search for the ISO9000 organization and all the pain in the ass things they make us do now.
that cylinder; it's the 2 lines which say it's level to eyelevel. Those 2 lines must be set against a calibrated level which was calibrated against another..etc...all the way
to the master standard somewhere. All measurement devices have a master standard somewhere. There is a metric gram in a vacuum cylinder along with a metric meter stick in Europe which holds the International Standards group. I wonder if they have a level somewhere which stands for the standard level? If you want to find out more about standardization, do a search for the ISO9000 organization and all the pain in the ass things they make us do now.