Metrology Meeting in Stuttgart/Germany

[kleiner Rainer]

Sounds good - but I have to leave early, because that day is also the European Bat Night, and as a member of the local "Naturschutzbund", I will show our schoolchildren bats in their natural environment. Metrology alert: we use "bat detectors" to make the ultrasonic signals audible and determine which species we observe (mostly Pipistrellus pipistrellus).

Greetings,

Rainer

[meandeev]

Every date will fit 

+1 vote for this one

Let's be a bit more specific, what about the 27th of August, with the possibility to arrive already on 26th of August?

-branadic-

[bastl_r]

Hello
Is this event for everyone?
Do i need a invitation to participate?
I only have a couple of kilometers to Stuttgart.

regards

[branadic]

Hi folks,

attached is the official announcement.
As alway the event is for everyone who registered to it. The registration info will follow prior to the event, not today. It's just that you have enough time to plan everything around that date.

I would also like to ask you for a contribution in form of a talk about a very interesting project you have been working on, such as a voltage reference, a resistor standard, a low noise amplifiers and such. That would help us all to make it an interesting and entertaining day. If you have any suggestion whom to ask for a talk, if you can make a contact to a very specific person that we could ask that would be very great too. Every support is welcome.

-branadic-

[branadic]

Hi everyone,

we are still looking for talkers and talks. If you like to contribute to the event or you know someone we could ask, please contact me. Thanks.

https://www.hahn-schickard.de/veranstaltung-detail/metrology-meeting-2022

-branadic-

[branadic]

Hi everyone,

in about 2 months from now we have the event happening. Since noone made any suggestion for talks yet and I wasn't successful in aquiring some interesting talks either, my suggestion is that every participant gets some ~10 min time with ~2 slides to talk about his/her most interesting project as a base for a fruitful discussion. What do you think about that?

-branadic-

[Ole]

Sounds good, I hope I can make it and at least visit.
Might be too new in the metrology scene to be holding a presentation...

[branadic]

The date for the event is coming closer, time to register for "Metrology Meeting 2022".

As always, send a mail to metrology@hahn-schickard.de with name, e-mail address, nickname and what you are about to bring with you.

Please notice, this years event will by in person only, so there is no remote access.
Everyone joining the meeting should prepare 2-3 power point slides for the open pitch to present recent projects, results, purchase or whatever as a basis for a fruitful discussion in our live session.

-branadic-

[branadic]

Note: As always everyone is invited to arrive on friday afternoon/evening to drop off and hook up equipment so it can warm up.

-branadic-

[branadic]

Let me remaind you all.
We will have a special guest with us giving a talk. It's noone else than iconic Prof. Dr. Klaus von Klitzing.
If you are still hesitating, during lunch you will have the opportunity to ask him questions face to face. Not yet convienced? 

-branadic-

[branadic]

In two weeks from now MM2022 will take place. Don't forget to register for it.

-branadic-

[alm]

I'm limited in what I can bring because I'll be traveling by train. So 35kg calibrators are out . Is anyone interested in measuring low resistance standards (L&N 10 mOhm and 100 mOhm), or high resistance standards (Keithley 5155 1 GOhm and Penn Airborne 100 GOhm), space permitting? Obviously both need specialized equipment to measure with any accuracy, which I won't be able to bring. I'd have a measure of their value, but probably nothing particularly tight, never mind traceable.

[MiDi]

@branadic: Thanks for organizing this event, highly appreciated!
Unfortunately I cannot be there this year, but I would like to participate remotely.

[HighVoltage]

In two weeks from now MM2022 will take place. Don't forget to register for it.

-branadic-

Sorry to say, but unfortunately I can not come this year and would participate remotely.

[maat]

Thank you all so much for the lovely presentations and especially branadic and C. for organizing the event.

I am so sorry I could not attend in person, because my whole family turned sick on Friday night  I hope to see you next year.

Anyway I uploaded my presentation on Github here: https://github.com/PatrickBaus/mm2022

[branadic]

It was again a very successful event, with interesting talks thanks to the open pitch session and the talk by Mr. von Klitzing, who took some time during lunch to answer questions, good discussions but also some intercomparisons of several references.
To be honest, I had expected a bit more feedback here, but also results presented from that day. At least the results from the EU CalClub test run have been posted:

https://www.eevblog.com/forum/metrology/eu-calclub/msg4385281/#msg4385281

-branadic-

[Sprock]

Hello Voltnuts
this review is a bit late after MM2022 Stuttgart. Nobody got time anymore, even so pensioners
André gave his intro to around 35 people and showed all his amasing previos projects.
Dont´d know when he sleeps!
He also managed to have a live session.
Among us older also lot of young international people showed up.
There were quite some colored and very interesting lectures.
Noise on high stability Oscillators  - Dr. W. Griebel
Automated Measurements - A. van der Meulen
My Ring comparison results - W. Vongehr
Three corner hat measurements - W. Oelschlegel
Horizon EDA - Lukas K.
Visit Taiwan Cal Lab - TIN
Home made Calibrator - J. Krummsdorf
Super PulsCaps - R. Schmitz
Measuring smal pulses M. von Rosenberg 
Selecting LM 399  P. Baus
Measurement Technology for the extreme Demands  E. Schreiber

Highlight was  Prof. Dr. Klaus von Klitzing talking about Quantum Hall Effect.

At the end every body could hold his Novel Prize medal with one exception -
nobody has to left the room before he got the medal back 
During lunch( finger food and drinks ) he gave a nice discussion before he left.

After then there were busy measurements with all sort of Instruments, References and Resistors.
Sorry for no more pictures. Only few space on the table were left empty.
André provided a 3458 witch was calibrated (+- 5.5ppm ) a few days before the event.
So everybody could compare his own Instrument or Reference to this value.
Wulf has done the 3 corner hat measurements to find the lowest noise performer
among F7000, W7000, F732A/B.
Now hopefully every body knows his " Volt - Ohm" respectively Referenc
with correction factor seen on the cal paper of 3458 Instrument.
André  also showed the Ring comparison results done from may to august.
For me the values varied in an small acceptable range, except one.
This was also a big success and now a good starting point for the next round.

A great THANK YOU  André and to all the contributors.

Hope to see you all healthy on the 4. MM Stuttgart also the this year missing people too.

Sorry, no pictures from all contributor taken.

  Sprock

[branadic]

At MM2022 Rainer Schmitz presented his idea of "SuperPulseCap as voltage reference" and brought some EVE SPC1550 with him. Fortunately, he gave me two of them for good reason, I wanted to test them in series for noise with the 0.1 - 10Hz LNA from user pipelie attached to my R9211 and did so today.
So the caps and the LNA input were charged to 7.4 V and everything connected inside a cookie box. Attached is the result. The noise we are looking at is essentially the noise of the LNA itself (100 nVpp).
So the caps can serve as a low noise reference to measure ADR/LTZ1000 zener voltage with nanovoltmeters like 34420A in difference mode.

-branadic-

[e61_phil]

Would be really interesting to measure the difference DC coupled. Even better against a proper reference. A slow drift downwards wouldn't be shown with the AC coupling of the LNA.

[branadic]

I agree, that would be interesting.
Wolfgang presented some measurements here: https://electronicprojectsforfun.wordpress.com/can-a-supercap-be-used-as-a-filter/ with worse result. I guess that is due to the 34470A itself, Echo suggested that this could be due to charges being transported during Azero.
I guess some low noise buffer behind the SuperPulseCaps could help.

-branadic-

[branadic]

During MM2022 the F700x system was running on battery, used on multiple instruments. During that time the low power LED on F7000-2 went red, so we directly reconnected the system to its power supply and everything seemed to be fine. It wasn't low enough to force a conditioning, puh.

After the event, when all gear was back in our temperature controlled lab for a while I measured F7000-1 and F7000-2 on our 3458A and went home afterwards. Back home, F700x was reconnected to my ADR1000 setup. During the next days of measurements I noticed a ~0.2 ppm jump between prior and post MM2022.
I ordered two new battery packs right the next day.

https://www.ebay.de/itm/192544097733

They meanwhile arrived and I hot swapped the packs yesterday - reference connected with its wall adapter to mains power, while battery pack was removed. Indeed, the battery pack of the suspicious reference already started leaking. Now that both references are back in the rack it seems like I got my ~0.2 pmm's back. More confidence to come within the next days. So please include that ~0.2 ppm's to your difference measurements.

For all W/F7000 owners, better replace your battery packs earlier than later.

-branadic-

[ScoobyDoo]

Hello Branadic - my Wavetek 7000 has undergone service and the original battery pack (10 cells of 850mAh NiMH) were replaced by 1700mAh cells (Ansmann) - I remember vaguely that we tried first NiMH cells with higher capacity - but those did not get fully charged with the FSM in place - hence we had to select a lower capacity - the autonomy should be around 18-20 hours after battery upgrade (850mAh => 1700mAh).

I am little bit worried that the cells of 2200mAh might not become fully charged - pls. verify

Herzliche Grüße/Meilleures salutations/Best regards

Best regards
ScoobyDoo

[bsdphk]

Can you try to measure the effect of changing temperature on the "supercap" ?

When I played with one (diff. type) I found it was very sensitive to temperature, to the point of being usable as a high-resolution thermometer.

[Okertime]

During the meeting, I measured the voltage difference of some voltage standards to my F732B
with a K2182 and logged the data with a sample rate of 62 ms.

Here are the mean values of the measured voltage differences:

F7000-1    -  F732B   =  -42.97 uV
F7000-2    -  F732B   =  -13.36 uV
W7000      -  F732B   =  -12.58 uV
F7000 Alm -  F732B   =  -64.64 uV
F732A Söh -  F732B   =   23.14 uV     not sure about the sign
F732A Ron  - F732B   =  -11.93 uV     not sure about the sign

Because I did not connect the measurement cables by myself to the last two instruments, I am not sure about
the sign of those two measurements.

When attached to my F732B, the calibrated K3458A multi-meter measured 10.000054 V for both polarities - averaged by eye. According to the calibration protocol, the measured voltage of my F732B is 10.000000 V +- 5.5ppm.

Than I used the program `Timelab`from John Miles to calculate the noise in form of overlapping Allan Deviation for
the measured voltage differences. The  first attached plot shows the ADEV curves with estimated error limits.
The second plot shows the same measurements in time domain.

Immediately after coming home from the meeting, I tested the performance of my F732B by measuring and logging the voltage difference to my F732A#2 for 37 hours. Nothing has changed.
The Allan Deviation of this measurement is shown in the black line in attachment three.
All ADEV curves in attachment three show the RMS values of the noise of a device under test together with the noise of the reference - the F732B. The absolute noise level of my F732B is know by using previous measurements and 3-cornered hat method. After removing the reference noise from the RMS values, the absolute noise level of the devices under test is received. Plot four shows Allan Deviation curves after removing the noise of the reference.

Allan Deviation curves are noisy as well but their noise can be reduced by measuring over long time. The measuring time during the meeting was limited and different for the DUTs. I estimate the AVEV curve to be trustworthy for F7000-Als up to 30 s, for F7000-1 and F7000-2 to 20 s and for W7000 to 10s.

I also attach a PDF with 3-cornered hat measurements on Voltage Standards. I am not proud about this document - it was made with a hot needle. But the measurements are OK.

My attachments disappeared - next try

[alm]

Thanks for the results! Does the knowledge of ADEV allow you to make a more accurate estimate of the uncertainty of the voltage difference you measured than basic sample standard error of the mean?

I calculated an uncertainty of 3.4 ppm for my 10 VDC measurements with branadic's 3458A based on GUM (k=2). The procedure was calculate standard error of the mean for my samples, convert the uncertainty of the calibration to standard error (95% confidence interval, so divide by 1.96), convert 90 day voltage specifications for 3458A option 2 to standard error by assuming it's a rectangular distribution, and add them all up as sum of squares, and multiply this by k. I'll publish the results when I'm done analyzing them all.