EEVblog

[@EEVblog]

At this level in the traceability chain all the standards labs send their references around to each other to keep them in periodic check. Note that this is a standards lab and not just a calibration lab, it has a higher level of certification.

[@ghffrsfygdhfjkjiysdz]

For those who care: The central calibration agencies (National Institute of Standards and Technology in US or JIST Japanese Institute of Standards and Technology in Japan or similar in other nations) of different nations each have their "golden" standard. For Example the mass unit of Kilogram has 8 cylinders of platinum-iridium metal in different labs across the world. Every so often those cylinders are brought together and have their masses compared with differences recorded. The cylinder in France is the only one that is exactly 1 kilogram; all other ones are very very close but not exactly. For example the cylinder from US NIST may be 0.999999997 of a kilogram. Then each national lab will have a set of secondary standards which are regularly calibrated by comparison to the NIST primary standard. Other cal labs would send their standard weights to be calibrated at NIST either against NIST primary standard (Crazy expansive) or against their secondary standards (very expensive). And then you send your scales or set of weights to these cal labs and they cal your part against their primary or their secondary standards. Each step removes the calibration further from the "world" standards increasing the uncertainty of the measurement. This is where the math comes in; to calculate the statistical, combined uncertainty of your part.

[@susceptibility_]

Thanks, this is what I was looking for.

[@piopett]

Me too 👍🏽

[@PaulTurner_Haizo]

Back in the mid-70's I was the chief digital instrument repairer at S.E. Labs Ltd, later Thorn EMI Datatech. Our fanciest instrument was the SM215 MkII Transfer Standard Voltmeter that cal' labs used for cell measurements. It only had a resolution of 1 uV, like the multimeter in your thermocouple video (that made me grin) but probably much lower uncertainty.

[@hankus253]

Well done Dave.

[@EEVblog]

Yep, it's just a bonus. It was going to be part of a larger one about the standards lab.

[@xm07]

I love the way how he doesn't want to tell Dave that they use qualified guess for uncertainty "calculation". I like this method - it save reaaaaly lot of boring calculations. :-)

[@EEVblog]

Yes, +/-1degC as opposed to the usual calibration lab across the hall that has a range of 5degC

[@sbreheny]

Not only do they have to all agree to within some uncertainty level but also ultimately the national labs derive their standards from either experiments which employ a fundamental physical principle (like some atomic resonance) or (less preferred) in a few cases a single international physical standard (like the kilogram mass standard, which is a physical object).

[@monad_tcp]

wait, are you implying Americans actually have a standard calibrated mass kilogram?.

[@davidmfra]

oh boy, i think you should watch this, America is actually on the metric system, they just convert it to imperial (lol): kzbin.info/www/bejne/iZ62e4t5a8Skh5o

[@rogertopful]

How do you calibrate the calibrating equipment? Then how do you calibrate that?

[@monad_tcp]

They said it, they calibrate at another calibrator's calibrator, then they make a coup, I guess, between them.

[@vencibushy]

Every measurement unit nowadays has a mathematical representation that is mostly based on constants. The only unit that still relies on a physical object is the kilogram. Every country has a national standard which is compared against a primary standard. For example - every national standard for voltage can be traced back to a Josephson voltage standard, which is the most accurate way to reproduce the definition for voltage.

[@tomjones9137]

Dave is like the Gad Fly of the tech sector...he's always buzzing around nosing into things asking questions and such.

[@andrewverran3498]

😂

[@UberAlphaSirus]

I don't think the younger crowd you have subbed can appreciate this level just yet. But I LOVE these types of videos. Thanks for the intel.

[@IIGrayfoxII]

How do you calibrate the calibrator? Then how do you calibrate the calibrators calibrator?

[@DMStern]

From the title I was expecting a bunch of engineers getting plastered in the pub.

[@jan.tichavsky]

When you get down to this kind of accuracy, you need to control the humidity as well as temperature.

[@bravedwarf]

This is amazing love this insight

[@TonyButchT]

DEEP!...But it cleared up some mystery! Thanks for this video!

[@ExplosiveAnyThing]

Thats a video i 've always wanted to see!!!

[@xm07]

HP3458 - that's the most annoying meter I've been forced to work with! There are loads of versions with different fw, so it's miracle if your software works with another one you used for development. :-) But it has unique features - there's no common meter that can sample as fast with such accuracy.

[@PaulTurner_Haizo]

Anyway, our chief engineer left to found his own company and while browsing the junk warehouses of Cambridge, I came across a bank of Weston Standard Cells fresh from a deceased cal' lab, but better by far than just the cells, they had the logs so we had traceability (after a bit of settling down due to moving) That was what made them worth many times what we paid for them.

[@TheSurvivalSecrets]

6:15 Dave playing with a light saber behind the camera?

[@Dreamer9317]

Felt like on a excursion, but thank you, great video.

[@thecobraman]

A VERY GOOD VIDEO DAVE

[@tcpnetworks]

So was he working for Algient?

[@ImSparticas]

Wouldnt the glass block window, if its an outside window, enable sunlight to warm the equipment casings above controlled ambient ?

[@SteelBlueVision]

+ImSparticas That's what the black pull-down screen is for...

[@Gameboygenius]

You should start these videos with something like "Les is a metrologist, not a meteorologist, from Australia, not Austria!"

[@andrewverran3498]

😂

[@varno]

How about you go to the Australian National Measurement Institute. I am sure they will have some interesting equipment there that you may be interested in. Perhaps having a look at some primary standards.

[@Sahko123]

How would you calibrate a calibrating calibrator(I have no idea what I just said)

[@ernststavroblofeld1961]

Sahko123 You send it to the NSA.

[@lordchavo]

What is that sound @6:16? Somebody playing with their light saber?

[@James_Bowie]

I'm still uncertain about uncertainties.

[@drpsht]

alien transmission at 6:15

[@BrunoPOWEEER]

So much POWEEEEEERRR hahaha

[@fpvtv9486]

They are set to a reference.

[@wesofx8148]

Calibration is serious.

[@paulf1071]

I understood about 5% of this video!

[@bcsupport]

No, he starts them off with "Hi!"

[@TheOriginalEviltech]

'Cause you must! Are you a metrologist as well?

[@JimGriffOne]

I guess the highest level of calibration is mostly about keeping the noise in the noise floor. Physics packages are probably the only way to produce any low-noise absolute references, but then the circuitry around them only introduces more uncertaintly. It must be a bitch to get these things calibrated!

[@leosedf]

Ohhh! A Greek guy! We are everywhere :P

[@petersage5157]

I thought this was going to be about calibrating Les.

[@MrCoontastic]

I though it would involve a Turbo Encabulator to calibrate a calibrator as is I fear the Milford trunnions will never reach a full state of sinusoidal depleneration. I am no expert though.

[@jix177]

Now..... lets go to the place where they calibrate the calibrator calibrator.

[@RandyLott]

Haha, it really does sound like it!

[@foxyrollouts]

nice vid

[@chupascz]

hmm, i don't get it.

[@vinshepard895]

Garrus Vakarian.

[@DanTheAppleMan]

But how do you calibrate the calibrator calibrators calibrators calibration calibr...wait, what ? Oh, just send it to someone else to do it.

[@Buciasda33]

This is a comic shit show of how primitive we are. We don't have exact references to define and recreate measurement units, like the meter (length) or Volt. We're basically monkeys and we're bringing our sticks together from time to time to compare them with each other, see if they drifted from the so called reference stick(s)

[@mschwemberger]

CAL-CEPTION

[@bojanche]

Calibrateception :D

[@sayalaperbandel]

Calibrationception

[@jordanjohnson714]

calibrate calibrate calibrate calibrate calibrate

[@sugminpurjo2]

God calibrated it...

[@flodins]

najpierwszy

[@postal2600]

I love meth :D

[@megasmart1337]

:D

[@ernststavroblofeld1961]

Why on earth are all these Agilent guys Meteorologists? Are those devices so fragile that weather plays such an important role? However, this calibration work gave all those Agilent lads quite some belly. And aren Agilent those guy who made your pince-multimeter that blew up and almost killed you, … Dave?

[@asj3419]

Their occupation is metrology, not meteorology. meteorology is the study the atmosphere. metrology is the study of measurment.