NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Measuring sensitivity of precision levels
From: Bill Morris
Date: 2009 Mar 1, 11:04 -0800
From: Bill Morris
Date: 2009 Mar 1, 11:04 -0800
Hein A rough and ready method is to mount it on a base of some sort. A 300 mm length of, say 6 mm x 25 mm cold rolled steel would do. Place that in turn on a reasonably flat, horizontal surface, ideally a surface plate, but the top of a saw bench would do. There will be some line on that plane that is horizontal. Find it by rotating base and level until the bubble centres. Insert a feeler gauge of known thickness under one end and observe how much the bubble moves. If the base of the level is reasonably long and the surface reasonably flat, you don't even need the extra bit of steel. This is the essence of the National Physical Laboratory Small-angle Generator except that it is more refined and uses slip gauges to generate the small angles. If you got a 20 second level for $20, you did very well. Bill Morris Pukenui New Zealand --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---
