September 9, 2014 Measurement Repeatability: How much is enough?
How many times have you looked at an interferometer specification and to see a number under Simple Repeatability like λ/10,000 and wondered, “Who cares?” Add to this the long footnotes that tell you how the number was obtained, usually through significant averaging, idealized short interferometer cavities (think 1 mm) and statistics from around 30 measurements. Then… read more »
April 22, 2014 Which Result is “Right”?
What accuracy can be achieved with an Interferometer? Instrument correlation sets a performance base line for metrology instruments. When parts are manufactured and shipped, correlation between vendor and customer is expected. If metrology systems do not correlate arguments ensue regarding who is right. Several years ago I received a call from a quality manager. He… read more »
March 21, 2014 Nothing lasts forever: Interferometer Upgrades
Summary The main culprit to interferometer failure is a computer crash due to drive failure. The main cost is often lost production due to down time. Planned upgrades of production systems can save hundreds of thousands of dollars in lost production. After 10 years it is best to plan an upgrade of all systems when… read more »