A2LA CALIBRATION OF 8590L

[step30044]

I have a quick question for you guys, just received an 8590L back from calibration from an A2LA accredited lab the certs list the following standards:
HP 11722A
HP 11792A
HP 11793A
HP 33120A
HP 33250A
HP 3325A
HP 3336C
HP 3458A
HP 53132A
HP 54845A
FLUKE 5700A
HP 83630B
HP 83630B (YES 2 UNITS LISTED DIFFERNT CAL DATES AND SERIAL NUMBERS)
HP 83650B
HP 83650B ( SEE ABOVE)
HP 8487A
HP 85027D
HP 8563EC
HP 8565E
HP 8662A
HP 8751A
HP 8902A
HP 8903B
TEK CG5011
TEK CPG5102
HP E4412A
HP E4418A
HP E8364B
HP E9304A
TEK 5G503
IGUU2916
RO1
TEK SG5050
TEK TDS540B

It appears that they have listed every std in the lab on the certificate is this "LEGAL" if so I do I identify what std's were actually used? how would they conduct a recall?  They also still list best measurement uncertainty, per our A2LA auditor this is no longer allowed. Any help would be greatly appreciated.

[flew-da-coup]

What lab did this?

[coastiecappy]

Looks kind of suspect to me. Have you questioned them as to why ? My assesors wouldn't let me get away with that.

[docbyers]

I vaguely remember somewhere a line about the documentation listing the standards used to calibrate the test equipment, NOT a list of every standard in their lab...  I can't find the reference off-hand, and it's been awhile, but when I send out anything for calibration, my contract or P.O. specifically states the minimum of standards data I need on the certificate (not the sticker); I'm sure yours does the same.  This vendor is ripe for a field trip- your QA guy/gal ought to pay them a visit.  Cappy's right- looks suspicious.  You don't want a supllier running fast and loose with their paperwork when YOU get audited.

[LarryH]

I concur - that IS probably every standard they own.  An on-site audit of their quality system would probably have them "tap dancing" all around the tough questions.  Like, "If your 8903A was found out of tolerance would you recall my 8590L Spectrum Analyzer?  Why/why not?" or "How was the IF gain calibrated on my 8590L?, IAW with what procedure?"  They fail to list a precision step attenuator (3335A or other direct step attenuator) and they would have to use a convoluted method of 8902A, 11722A, sig gen and an "N" splitter to correctly check IF gain.  All the Navy, Air Force and HP manuals use a 3335A sig gen for these precision step checks on HP spectrum analyzers - as far as I can recall.

Another point on the 3335A.  This is an EXTREMELY accurate and repeatable attenuation source.  I kept one charted vs. a freshly calibrated 8902A (corrected during IT's calibration).  From this point on, any time I had a question about an 8902A on its measurement, I could connect this 3335A and run a quick op's check.

[flew-da-coup]

Did you ever find out what this lab was doing or not doing?

[step30044]

Yes, they were listing every std that was in the lab, I dont want to name the lab as it WAS  one of our competitors ( I will say that they are located in Iowa).

[flew-da-coup]

E...O?

[step30044]

lets just say the "world " is there play ground

[RFCAL]

I would question that one myself.Looks like you got mislead somewhere.

[CalLabSolutions]

I do not see a power splitter listed.. 

I do not know of any procedure to calibrate a Spec An that does not use a power splitter.

[griff61]

Not very WORLD class CALIBRATION practices if you ask me...

[mdbuike]

I do not see a power splitter listed.. 

I do not know of any procedure to calibrate a Spec An that does not use a power splitter.

I believe the 3585 doesn't use a splitter, nor the 3581, since the procedure uses the 3335 due to it's accuracy.

Mike

[Bryan]

I suppose one could overlook the splitter presuming it was characterized at the time of test.  Since the 8590L is only 1.8 GHz a source could run to a splitter with the E9304A on one side and 11722A on the other, one is used a a standard, the other a reference.  The frequency points are checked and the standard sensor removed and connected to the 8590 while the reference remains in place to ensure matching levels are used.  Agilent does a similar routine on the ESA/PSA series with thier software. 
On the other hand one could characterize the source at the end of a cable with the sensor then remove it and connect to the 8590.  I do this ocasionally for higher frequency models where power loss through the splitter is a concern though it would best be done with a 6 db pad at the end of the cable to help with mismatch, that pretty well equals the splitter loss though, that's why I said "would best be done"
This is all moot though, they just listed all thier junk.  I've seen worse.

[CalLabSolutions]

Good point Bryan.  I agree it it can be done with out a calibrated power splitter, but doing it that is more work.  I have seen Agilent procedures that characterize the sensor below 3 GHz, but they have to keep the uncertainties down.

The question to me is what procedure did they list.  If they listed the manufacturer's manual. It has been a while sense I calibrated an HP 8590L. But if memory serves me correctly, they they should have listed a power splitter, directional coupler and some attenuators.  Even if they characterized the power splitter for frequency response, they still had to do gain compression and third order inter-modulation. 

I find it funny that they are list all the standards, but not really. Some how they did not list key standards that are accessories required to do the calibration correctly.

That is just my 2 cents..