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!
Check out our section on how calibration factors are derived for power heads.
More content coming soon!