Mark Rand
Diamond
- Joined
- Jul 9, 2007
- Location
- UK Rugby Warwickshire
I know the recommended NIST/NPL way of calibrating a pentaprism is to use two autocollimators and two mirrors like in this link.
Since I haven't got two autocollimators, is it reasonable to sit one autocollimator and the pentaprism on a surface table with the pentaprism directing the light up to a mirror mounted above it. Adjusting the mirror to get a datum reading. Then rotating the pentaprism and autocollimator by 180° horizontally. Then taking the indicated error of the mirror angle as twice the error of the pentaprism? This does assume that any adjustable feet on the autocollimator don't move during the process, of course.
Can anyone shoot this down in flames or offer a simpler method that I've missed?
Since I haven't got two autocollimators, is it reasonable to sit one autocollimator and the pentaprism on a surface table with the pentaprism directing the light up to a mirror mounted above it. Adjusting the mirror to get a datum reading. Then rotating the pentaprism and autocollimator by 180° horizontally. Then taking the indicated error of the mirror angle as twice the error of the pentaprism? This does assume that any adjustable feet on the autocollimator don't move during the process, of course.
Can anyone shoot this down in flames or offer a simpler method that I've missed?