Hi N8ZM, et. al.:
Thanks for that.
I didn't know that Keysight (a.k.a. Agilent, a.k.a. HP) being a N.I.S.T. certified cal lab (through all the company's incarnations) was using cal equipment traceable to N.I.S.T!
Did you read the thread I posted: the one the OP above is referring to? (By the way, the OP didn't... yet spawned this orphan thread, the we are now embroiled in!)
Just because one sub-system of a system was "accurate," under N.I.S.T. laboratory conditions, at some N.I.S.T. certified lab, some time in the past... that does not mean the overall system being now used in the field is "accurate."
IMO it is gullible to maintain that a 20 year old, well worn, 150 USD 8481A, from some vendor, who tripped over it while dumpster surfing... and then added it to the Tiffany Lamp shades, he/she has for sale...on an online auction site. In my opinion, it is gullible to maintain that such a metrology device is now traceable to N.I.S.T.
Accuracy, precision, resolution, repeatability, robustness... these are all distinguishable. Guys/gals picking up that bargain HP power meter, at the hamfest... and now looking for a "head"... They might have forgot what they learned in their graduate school statistical metrology course.
And so, IMO, and allegedly... they are being taken advantage of by unscrupulousness vendors flying the caveat emptor flag.
If you buy an N8481A for about 1800 USD, or you send your bargain 6481A into Keysight for repair exor cal... then you'd still need cal on the hamfest power meter... and then you'd still have to use the right technique, under the right conditions, to get power measurements within Keysight's specs.
If someone thinks I'm wrong... I'm listening.
Best regards.
