Re: (ATM) Foucault testing technique
Clay Spence x3039 (cds@peanut.sarnoff.com)
Tue, 22 Aug 1995 09:22:18 +0500
There's such a thing as systematic error, too. Just averaging a bunch
of repeated measurements will reduce random measurement error, but not
the systematic errors. I'm not sure what they would be. For a
long-focus mirror, a person might tend to move the knife edge a minimum
distance, thus tending to make all readings a little large. Or the
random errors might not be evenly distributed on both sides of the
correct displacement for a long-focus mirror, so the average will come
out biased toward too large a displacement.
Clay Spence
cspence@sarnoff.com