Older TE NIST calibration/certification expectations. - Page 1
Forum section: electronics / testgear

author: HalFoster
author_rank: Frequent Contributor
timestamp: June 13, 2019, 03:50:37 pm
content: All-I am wanting to send in my personal HP 3335A and 8663A to a local cal lab. I've had very good experiences with them on simpler gear, but for these two I asked them for more specifics on exactly what would be tested. To me, I would want in effect the tests per HP's Performance Test result sheet for that instrument. That being said, is it even remotely realistic to expect a lab to have that information to begin with? When I asked, the reply was, quote, "Performance tests for accuracy of frequency, power, etc are tested."I don't doubt that the basics - frequency and attenuation - would be tested, but I wonder about things such as harmonic distortion, flatness, spurs, phase noise and such that are specified in the original documentation and, to me, are part of any complete NIST certification. The answer I got above doesn't exactly fill me with the warm 'n fuzzies about that.So - what would be realistic to ask for and/or expect?Thanks,Hal

author: Tony_G
author_rank: Super Contributor
timestamp: June 14, 2019, 06:24:59 am
content: I prefer to go direct to the OEM (Keysight in my case for the bits I got calibrated). While there are very good 3rd party labs, there are also some absolute cowboy organizations out there. I don't cal enough gear on a regular enough pattern to go through the trouble of working out the good from the bad. YMMV.Regardless, I would expect nothing less than a report covering the exact items specified in the manual. If they don't do that as the default then I'd be inclined to select another lab. Neither the 3335A or the 8663A requires test gear outside of what a good RF capable lab should already have on hand.You might be able to ask them for a sample report covering the gear.TonyG

author: Henrik_V
author_rank: Regular Contributor
timestamp: June 14, 2019, 07:05:10 am
content: You always can ask for a quote including an cal-cert example (incl. the uncertainties).

author: HalFoster
author_rank: Frequent Contributor
timestamp: June 14, 2019, 02:05:55 pm
content: Excellent input... I'll shoot an inquiry at Keysight or whatever it is they are calling themselves this week and see - I have a feeling that the numbers I get back will be... substantial.Thanks,Hal

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: June 14, 2019, 06:28:53 pm
content: You can't go wrong with them. Keysight maintains and cal most of my Keysight/Agilent gears, you cannot go wrong with them. Price is a little higher, but if you don't have good alternatives, the assurance of things done right every time outweighs any savings you have. I only do cal every other year to ensure they are all NIST traceable, the additional cost is minimal when you spread it out over 2 years.The other advantage is if you need repair in case they fail cal, they can do that for you as well.I have an account with them, quotation, billing and payment are painless. They are exceptionally professional, helpful and easy to do business with, they inherited all the good genes of HP from its glory days, still dedicated to serving the engineering community.

author: PedroDaGr8
author_rank: Super Contributor
timestamp: June 14, 2019, 08:28:42 pm
content: You definitely have to make sure that the cal lab knows what it is doing. Back when I wanted to get my 34401A cal+adj (keep in mind they are not the same), there were several labs that wanted to use equipment with worse specs than the 34401A, others quoted equipment which would mean ranges like the lowest current or highest voltage range would not be calibrated.I ended up going with Global Test Equipment because they clearly knew what they were doing and had an unbeatable $75 special (now $99) for a NIST traceable cal+adj with full report and free shipping back to me. Service was great and very communicative, turnaround time from when they received the instrument to when I had my instrument back in my hands was a VERY reasonable 6 days. The report was about 5 pages of data including as found and post-adjust results in detail. You can see more details inthis thread. While they have a list of models of instruments for this special, a number of others have asked about their non-listed instrument and GTE said the special applied to those instruments too.

author: NoisyBoy
author_rank: Frequent Contributor
timestamp: June 14, 2019, 09:36:10 pm
content: I second that.Noticed my earlier comment about Keysight, I said "most" of my cal were done by them.GTE is my other go-to, I use them because they are local and I don't have to risk shipping damage. They do local pickup and delivery for free, which is convenient for me, and I know the sales team pretty well. Some simpler cal are done locally, the more involved cal were done in Arizona if I recall correctly. They just did a 34401a cal for me a couple months ago, the cal equipment used for above what Keysight requested. It is $99 now, with full report, well worth the money.I have also used Tektronics for my Agilent system power supplies, no issues.However, I still put Keysight at the top spot as they can do repair or equipment swap if there's anything out-of-the ordinary, at least for the current products anyway.