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Metrology
Updated September
10, 2010
New for September 2010! When
using any type of RF test equipment the user must know that the
measurement is accurate and there is traceability to a known standard
such as maintained by NIST.
That traceability to a known standard is the sceince of metrology.
Did you ever wonder where the "cal stickers" came from
when you pick up a piece of test equipment from the pool? They come
from the metrology lab. Metrologists must be jacks of all trades,
as they have to understand everything from DC to terahertz to optics.
In some cases, equipment can
be calibrated by the user at test, or perhaps the accuracy of the
data does not need to be pristine (as in functional checks). But
for deliverable hardware that your company's name goes on, you want
the confidence that periodic checkups by metrology provides. Often
a user can find a problem with test equipment well before it is
due for calibration; for example, a noise source that gives widely
varying data across frequency may have a trashed connector that
you can confirm under a microscope. Time to send it to the cal lab,
they can do the repair or send it back to the manufacturer!
Every microwave company that
is reputable has either their own metrology department, or contracts
this function outside to a company that specializes in it. Perhaps
someday a metrology company will sponsor this web page!
Here's a forum
on metrology, hosted by TEGAM. Here's
information on how calibration factors are derived for power
heads.
More content coming soon!
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