EEVblog #1039 - Keysight Metrology Standards Lab - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: November 18, 2017, 05:54:56 am
content: Peter Daly from Keysight takes us into the Metrology Standards Lab at Keysight in Melbourne Australia.Looking at the RF standards and test rack and detailed looks at metrology grade RF connectors.Standards lab vs calibration lab, and traceability.

author: Vgkid
author_rank: Super Contributor
timestamp: November 18, 2017, 06:46:03 am
content: I really enjoyed it.Will this end up being a short series , or a one-off video.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 18, 2017, 06:50:31 am
content: Quote from: Vgkid on November 18, 2017, 06:46:03 amThere are two more videos coming up. If I understand correctly, this was some material shot but never edited, so there's one or two older videos that did get released too. I think it's the mobile calibration lab one and maybe another. I suggest looking at the calibration and standards playlist.

author: EEVblog
author_rank: Unknown
timestamp: November 18, 2017, 07:14:32 am
content: Quote from: Vgkid on November 18, 2017, 06:46:03 amTwo more video are uploaded and will be released

author: sibeen
author_rank: Frequent Contributor
timestamp: November 18, 2017, 08:18:23 am
content: When was this video shot as I notice Peter is still wearing an agilent name tag.I did my original electronics with Peter, starting back in '79, so have already sent him a text message calling him a boofheafd

author: Brumby
author_rank: Unknown
timestamp: November 18, 2017, 09:19:22 am
content: Quote from: sibeen on November 18, 2017, 08:18:23 amDave mentioned a period:Quote from: EEVblog on November 16, 2017, 12:17:41 pmEEVblog #420 - What Is Calibration?features Peter Daly and was uploaded on Feb 7, 2013

author: Dr. Frank
author_rank: Super Contributor
timestamp: November 18, 2017, 09:46:41 am
content: Quote from: sibeen on November 18, 2017, 08:18:23 amFrom different cal stickers in the lab, you can estimate, that this video was shot between 29th January and 16th March of 2013

author: PA4TIM
author_rank: Super Contributor
timestamp: November 18, 2017, 10:21:14 am
content: Nice video. I like to see more about standards an calibration.I repair measurement and calibration gear but on a whole different level. I repair calibrators manufactures do not support anymore because of age.Like you see in the Keysight lab they often like to use old gear because of the history they have on it. Besides that, it is far from cheap to replace a calibrator or standard and then you have to build up the confidence over time from scrap.I keep a weblog to show some of my work but I ask up front if they mind that I do that (without telling who the owner is) but many do not want that. It is a rather "closed" branch and often smal specialized labs work together. I sometimes repair gear for a distributors/dealers because otherwise they have to send it to the manufacturer in a different country. But they do not want publicity about that. I do not care, i just love repairing this sort of gear.But I also see the not so nice side of the branch. I repaired several calibrators that were non-repairable according the manufacturer and often they were send in with already a minor problem for repair and calibration. They then "died" during calibration and tell the customer they tried to repair it but failed. 3 of those cases from 2 very big brands came in and turned out to be sabotaged. One only had a (power)connector hanging loose. A locking one and the manufacturer told the owner they had tried to repair it. I pushed in the connector and replaced the backup battery and it was fine again.Also spicy was a company that wanted to send a "calibrator/tester" to the manufacturer but the customer was a big company with a lot of paperwork they send upfront to you that you have to sign and mail back etc and that went OK, But two weeks later the manufacturer called to tell they had tried but could not repair it and that was a lie. Why ? Because the customer made a mistake, it turned out the dead tester was never send.The other one was the same story but a different brand. Here they switched two connectors. The real problem was a bad relais.I repaired a meter calibrator that was calibrated by the brand and failed calibration. The funny thing was that 1 failed function was no fail but a calibration mistake (WTF) but worse a passed function was in fact a faile. A DC range had such a strange combination of faults that it looked by accident in spec if you used a very good filtered meter. I found that while I was repairing it also by accident, this was not a sabotage action. Just bad luck.But these thing are just funny to see from my side, not for the owners and (I am sure) are exceptions, most cal-labs and manufacturers are very serious.

author: sibeen
author_rank: Frequent Contributor
timestamp: November 18, 2017, 10:22:11 am
content: Got a text back from Peter and yep it's from 4 years ago. I think he's a bit surprised that Dave has resurrected the old tape as according to Peter, Dave got a bit of stick for being a 'paid shill for Agilent'. Peter reckons if there was corruption going on he would have paid himself first

author: HighVoltage
author_rank: Super Contributor
timestamp: November 18, 2017, 10:32:25 am
content: Very nice video!Dave, you should go back there and make a similar video about each of the calibration divisions in the lab.So, based on explanations, the BNC connector is only good for up to 500 MHz but Keysight is using it on the 6000X scope for up to 6 GHz? Hmmm?Also interesting what he said about storing calibration documentation.

author: lukier
author_rank: Unknown
timestamp: November 18, 2017, 10:49:16 am
content: Quote from: HighVoltage on November 18, 2017, 10:32:25 amAFAIR that's no standard BNC. free_electron explained that here:https://www.eevblog.com/forum/blog/eevblog-316-more-pfang-more-13ghz-scope-more-pulser/msg130496/#msg130496

author: retrolefty
author_rank: Super Contributor
timestamp: November 18, 2017, 05:49:03 pm
content: Cal lab stuff bores me once Dave and the guest confirmed (in their opinions) in the past that "Calibration of a device does not involve any adjustment or correction of that device". Given that, I would only use their service when some law or regulation requires me to, not because I think there is value in using their $$$ service.I feel what they are selling is validation not calibration, as the unit being "calibrated" will perform the same when it leaves their lab as it did when arrived at their lab, only paperwork is produced.?

author: SAI_Peregrinus
author_rank: Contributor
timestamp: November 18, 2017, 06:23:52 pm
content: Quote from: retrolefty on November 18, 2017, 05:49:03 pmI replied on Youtube but this is probably a better place. Personally I find precision measurements quite interesting, and calibration certainly involves that.Anyway, you seem to have a fundamental misunderstanding of what calibration is for and how it's used. As an example I'll use gage blocks: precision length blocks with very smooth lapped ends which can be "wrung" together to form extremely accurate end length standards. They're used ALL THE TIME in machine shops. They can't be adjusted: they come precisely to length. As an example a grade 00 10mm long gage block from Mitutoyo can deviate +- 0.07um from nominal at any point with a limit for variation in length of 0.05um Pg 3. If more than 7 microns of wear occurs it can't simply be adjusted back to size, you'd need to buy a new one. There's no way to adjust them, they're just pieces of ceramic of a very precise length. Yet they still need calibration, so that you can track the wear and determine the corrections needed for any measurements made when using them.Likewise with electronics. You simply add the calibration values as offsets in your analysis software, so your measurements remain precise and accurate without ruining your ability to interpolate the error changes over time.

author: Razor512
author_rank: Regular Contributor
timestamp: November 18, 2017, 10:02:37 pm
content: How do the companies maintaining the frequency standards handle issues relaying to global inaccuracies, for example if everyone's standards equipment has some kind of drift, wont there be some kind of global drift that happens over time?Hypothetically speaking, if you take a frequency standard infrastructure from today, and went back in time and compared it to the same systems from 15 years ago, would there be a measurable drift. If so, would that impact the performance of modern equipment??

author: SAI_Peregrinus
author_rank: Contributor
timestamp: November 18, 2017, 10:42:56 pm
content: Quote from: Razor512 on November 18, 2017, 10:02:37 pmThis sort of drift is only actually an issue for mass, since that's the only standard that's currently defined based on a prototype object. All the rest are defined based on seemingly invariant properties. Frequency is based on the hyperfine splitting of the caesium-133 atom. Mass will be redefined soon, to eliminate the issue of the international prototype kilogram and its copies drifting apart.https://en.wikipedia.org/wiki/Proposed_redefinition_of_SI_base_units#SecondThus a caesium atomic clock can provide an output signal of exactly 9.192631770 GHz. In practice the output is internally stepped down to lower frequencies and amplified to usable levels, typically at least a 10MHz sine wave. This conversion is a major source of inaccuracy in caesium frequency standards.

author: narfson
author_rank: Newbie
timestamp: November 18, 2017, 10:53:14 pm
content: Might it be possible to put the traceability documents as seen on the wall online? Would be nicer to read compared to the video.

author: EEVblog
author_rank: Unknown
timestamp: November 19, 2017, 12:22:17 am
content: Quote from: HighVoltage on November 18, 2017, 10:32:25 amWell they have actually invited me back to bring a bit of kit and film the whole (likely boring to most!) process of having it calibrated.I'm not sure how exciting a video that would be?

author: EEVblog
author_rank: Unknown
timestamp: November 19, 2017, 12:23:39 am
content: Quote from: sibeen on November 18, 2017, 10:22:11 amNot sure why I didn't release this, maybe I thought it wasn't that interesting, or I just put it aside and meant to edit later but caught up with other stuff etc.

author: EEVblog
author_rank: Unknown
timestamp: November 19, 2017, 12:25:48 am
content: Quote from: retrolefty on November 18, 2017, 05:49:03 pmYes, but there can be great important in that "paperwork". You have to understand the benefits of the entire tracability chain, and it's not easy to convince someone of those benefits, especially an individual for which there is basically no real benefit.

author: EEVblog
author_rank: Unknown
timestamp: November 19, 2017, 12:27:35 am
content: Quote from: sibeen on November 18, 2017, 08:18:23 amShot 6th Feb 2013I was shuffling RAID drives the other day and came across it.

author: tautech
author_rank: Super Contributor
timestamp: November 19, 2017, 06:17:33 am
content: Quote from: EEVblog on November 19, 2017, 12:22:17 amTo some boring but to most informative.But what to take ?Your best kit (for personal standard usage) or some relatively new equipment to check how accurate factory calibration might be.

author: TheSteve
author_rank: Unknown
timestamp: November 19, 2017, 06:41:38 am
content: Quote from: EEVblog on November 19, 2017, 12:22:17 amI'd like to see it, we know you have a 34470A - you can compare its readings to when it was originally calibrated. Maybe take a scope, and if they will cal non-Keysight gear for you then the Keithley 2400 SMU would also be nice. And your 10K resistance standard. If parts of the cal drag on you can always trim the delays out.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 19, 2017, 09:55:43 am
content: Quote from: EEVblog on November 19, 2017, 12:25:48 amCovering your ass when things hit the fan is the purpose of most paperwork, and it makes life a lot easier when you need it.

author: Mr. Scram
author_rank: Super Contributor
timestamp: November 19, 2017, 09:57:38 am
content: Quote from: EEVblog on November 19, 2017, 12:22:17 amMaybe not very exciting, but with proper commentating it could demystify the calibration process for a lot of people. Rather than voodoo performed by men with stickers, it should become much more tangible.

author: narfson
author_rank: Newbie
timestamp: November 19, 2017, 10:44:27 am
content: Quote from: Mr. Scram on November 19, 2017, 09:57:38 amMaking it much more tangible, yes:When you go back to Keysight, you might find a suitable bit of gear in the metrology dumpster to serve as the primary EEVblog community standard. They might want to ensure that even the gear they throw out is up to nist standards would be my guess, and even film that for you kindly. Then why not save on shipping cost, and on the way back to you from nist, the device goes to a fellow youtuber that lives nearby, and uses it to create a secondary standard before sending it to the next one...Then, at least, we would have traceability to a dumpster find!You never know if there isn't something in there that still can top the last find...

author: HighVoltage
author_rank: Super Contributor
timestamp: November 19, 2017, 02:10:03 pm
content: Quote from: EEVblog on November 19, 2017, 12:22:17 amOhh, please take your 34470A and have them check the values and then perform and spot on calibration.I think lots of people in the metrology section would be very much interested to see how Keysight actually does this procedure.

author: joeqsmith
author_rank: Super Contributor
timestamp: November 19, 2017, 05:00:12 pm
content: Thanks

author: Andrey_irk
author_rank: Regular Contributor
timestamp: November 20, 2017, 05:08:31 am
content: Quote from: EEVblog on November 19, 2017, 12:22:17 amIt won't be for the majority of people. In fact, they aren't interested in anything but arduino, raspberry etc.But it will be perhaps the only video on youtube ob how metrology labs calibrate electronic equipment. How about calibrating 50GHz PNA or something like that? They calibrate mostly RF equipment, don't they?It's a pity when you see that guys like Shahriar have in order of several magnitudes less views than someone playing computer games. But that is what the majority wants.

author: LA7SJA
author_rank: Regular Contributor
timestamp: November 20, 2017, 10:56:28 am
content: I promise to watch every second of a calibration video if you decide to make it. I maybe even push the thumb up.Johan-Fredrik

author: PA4TIM
author_rank: Super Contributor
timestamp: November 20, 2017, 06:29:40 pm
content: Doing a calibration is not a very exiting thing. There is often not much to see. In one of the later video's they tell an automated SA calibration takes a few hours and doing it by hand 7 to 8 hours.A lot of time in doing it by hand is setting up all the gear needed for every step and a lot of waiting. And if it is gear you do not do every week it takes a lot of time to look up specs and procedures.And for Retrolefty, this is a typical hobby reaction. You do not have a clue what the whole thing about calibration is about. I repair calibration gear and often customers tell me not to adjust a thing unless there is no other option. And if I need do that, they are not happy and want to know that.

author: narfson
author_rank: Newbie
timestamp: November 21, 2017, 09:08:23 pm
content: When I was a kid, I had no clue about calibration. For sure, it held some dark fascination.First Computer of mine was VIC-20 that I got on Christmas '83-- my first own photo camera was, same year I think, one Kodak Disk 4000 series.First time that my dad let me drive on my own in his car was on a sunday morning at the Hewlett-Packard employee parking lot in Böblingen (Germany, I was around 12 or 13). My first calculator that I bought with my own money, quite expensive, was a HP 48G.So -- I wonder, whatever happened to clock 5061A #3 -- has it ever been used to calibrate HP house clock in Boeblingen plant? Which I read has been the plant, at which HP introduced flex time around '67 first for their employees (I just learned). (IBM, HP, Mercedes had major operations in the town I grew up.)I never really knew what HP was about, what they were doing at this plant, I have to admit-- I bet though, one still today would be able to calculate the influence of those flying HP clocks on world time. Not exciting enough?

author: PA4TIM
author_rank: Super Contributor
timestamp: November 21, 2017, 09:23:50 pm
content: QuoteNice story, calibration as a concept is very interesting and the gear needed can be exiting. I only wrote about doing a calibration. I quote the words of the owner of a cal-lab about doing a calibration, "you can teach a monkey to do it" F.i a DMM, set the meter calibrator at 5V, connect it wait until it stabilizes, note the value and dial in the next value. But aligning a high end analog scope is something else

author: narfson
author_rank: Newbie
timestamp: November 21, 2017, 09:37:15 pm
content: Well, I'm still wating for my copy of "Metrology for Philosophers" I would reply.