Author Topic: USA Cal Club: Round 2  (Read 83092 times)

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Offline Conrad Hoffman

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Re: USA Cal Club: Round 2
« Reply #725 on: June 09, 2021, 03:03:29 pm »
Plus a standard capacitor, maybe a bank of NP0 types, a dissipation factor standard and an inductance standard! Shouldn't take up much extra room.
 
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Offline rhb

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Re: USA Cal Club: Round 2
« Reply #726 on: June 15, 2021, 06:02:51 pm »
I'm very much with Conrad on adding some other reference standards.

I'd also like to point out that Doug Malone's  DMMCheck Plus from voltagestandards.com is an excellent piece of affordable kit.  I've been using mine to check an ebay 3478A that came a few days ago.

Have Fun!
Reg
 

Offline SilverSolder

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Re: USA Cal Club: Round 2
« Reply #727 on: June 15, 2021, 07:57:57 pm »
I'm very much with Conrad on adding some other reference standards.

I'd also like to point out that Doug Malone's  DMMCheck Plus from voltagestandards.com is an excellent piece of affordable kit.  I've been using mine to check an ebay 3478A that came a few days ago.

Have Fun!
Reg

+1  for voltagestandard.com

They also have a 0.002% 10V reference which works very well:
https://voltagestandard.com/002%25-10v-reference
 

Offline guenthert

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Re: USA Cal Club: Round 2
« Reply #728 on: June 16, 2021, 03:36:51 pm »
[..]
I'd also like to point out that Doug Malone's  DMMCheck Plus from voltagestandards.com is an excellent piece of affordable kit. [..]
     It does what it promises (verifying multimeters to moderate accuracy) and for its intended purpose it's a good value, but it isn't ideally suited for application in metrology.   I wished he'd have used terminals with low thermal EMF.  The resistors used don't instill confidence in long term stability either.
 

Offline rhb

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Re: USA Cal Club: Round 2
« Reply #729 on: June 17, 2021, 12:52:42 am »
I also have the 10 V reference.

Neither is metrology grade, but they *are* affordable references for most practical purposes.

A budget metrology grade version of the DMMCheck Plus would run well over $1000 and probably cost 10-15% of that per year for cals.  Those last few decimal places get expensive quickly.

Have Fun!
Reg
 

Online CatalinaWOW

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Re: USA Cal Club: Round 2
« Reply #730 on: June 17, 2021, 01:05:16 am »
Having a lower quality reference is one approach to getting a faster cycle time, which in my opinion would be the largest improvement that our club could have.  None of us who don't pay for formal calibrations has had two measurements with the same reference since the club started.  So we can only guess about stability of our equipment.   As far as I know TiN is the only one to have multiple observations on the same reference so our window into the stability of the reference is limited.  Fortunately due to the quality of his measurements we can have fairly high confidence in that small window.

While a couple of the stops in the current and previous cycle have tried to look at longer interval (days or weeks) stability, it doesn't appear that lengthy observation periods are the main reason for the long cycle times. 

Perhaps the next cycle through will be quicker just because of experience, but anything we can think of to help the process is worth considering.
 
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Offline rhb

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Re: USA Cal Club: Round 2
« Reply #731 on: June 17, 2021, 10:14:07 pm »
I also think shortening the cycle time would be very helpful.

I suggested having a 2 tier set of kits for voltage and an additional kit for RF for round 3, but no one seemed to be interested in the RF and not much enthusiasm for a 2 tier voltage set.

I bought an HP RF power meter calibrator specifically for round 3 and have some capacitors and inductors which should be pretty good if properly packaged.  But I seem to be the only RF oriented person.

For lower tier DMM cals, I think a DMMCheck Plus and/or 10 V reference that circulated quickly with stops at Doug Malone's shop every 12 months would be useful for many people who are not volt-nuts, but simply want a cheap annual cal verification.

That said, both of my 34401As were well within spec despite age and heavy use and I'm not trying to wring the last bits of accuracy out of them.

Have Fun!
Reg
 

Offline bitseeker

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Re: USA Cal Club: Round 2
« Reply #732 on: July 02, 2021, 05:43:53 pm »
Perhaps the next cycle through will be quicker just because of experience, but anything we can think of to help the process is worth considering.

Having the familiarity of at least one round under our belt should help speed up the process, although one could argue that the long cycle time contributes to that familiarity fading by the next round.

Refreshing one's recollection of the kit, prepping one's testing setup, and having a defined process to execute (and/or automation) prior to the kit's arrival can help with turnaround as well.

I'm behind on updating the docs for the kit, so I need to address that as well.

Apart from having more than one kit, any other ideas for improving our efficiency?
TEA is the way.
 

Offline TiN

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Re: USA Cal Club: Round 2
« Reply #733 on: July 02, 2021, 06:21:14 pm »
Perhaps someone with web-programming skills could write a simple page, that would show queue of people in loop, and where the kit currently is?
Or even step further - add data fields so members can upload their measurement results and data, so there is one nice combined page with all measurement results and time slots. This can be used to finally plot members results equivalence plots and deviation between each lab. Yea, I know, dreams...   :=\
YouTube | Metrology IRC Chat room | Live-cam | Share T&M documentation? Upload! No MB limit, firmwares, photos.
 
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Online CatalinaWOW

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Re: USA Cal Club: Round 2
« Reply #734 on: July 02, 2021, 06:36:57 pm »
Perhaps the next cycle through will be quicker just because of experience, but anything we can think of to help the process is worth considering.

Having the familiarity of at least one round under our belt should help speed up the process, although one could argue that the long cycle time contributes to that familiarity fading by the next round.

Refreshing one's recollection of the kit, prepping one's testing setup, and having a defined process to execute (and/or automation) prior to the kit's arrival can help with turnaround as well.

I'm behind on updating the docs for the kit, so I need to address that as well.

Apart from having more than one kit, any other ideas for improving our efficiency?

I think you have identified the most important speed up points.

Prepping your equipment and having a plan of action.  There is always a few weeks warning of when it will get to you.  Setting up and doing dry runs on local sources (can be as simple as a battery) saves lots of dwell time.  In both arrivals at my place the prep work uncovered surprises in my instrumentation that needed significant time to rectify.  Even with this prep work there were last minute adjustments, fortunately taking only hours, not days.  Things like lead lengths and places to put the DUTs are the kind of simple things that can take a fair amount of time to deal with. I am sure others have found surprises too.
 
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Offline Conrad Hoffman

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Re: USA Cal Club: Round 2
« Reply #735 on: July 03, 2021, 01:22:15 pm »
The best laid schemes o' mice an' men...

Yes, both times I thought I was well prepared and all manner of issues still came up, even having to rebuild failed equipment.
 

Offline jjoonathan

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Re: USA Cal Club: Round 2
« Reply #736 on: July 06, 2021, 09:08:28 pm »
Another way to organize it in the next round might be to do away with the list and instead have each person put up a post when they finish with the kit: "Kit available, who wants it next? First to post proof wins." Proof would constitute a fresh dry run on an alkaline AA or something.

If competition gets too heated, we could chill it with a "dibs" system -- accept the top two entrants from every other post or the top three from every third, etc. If we turn this knob all the way to N we transform the competition system back into the reservation list system.

Just a thought :)
 

Offline bitseeker

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Re: USA Cal Club: Round 2
« Reply #737 on: July 06, 2021, 11:20:28 pm »
I like the "I'm ready" concept. Sometimes you may not even want it when it's officially your turn. I think that's happened a time or two.
TEA is the way.
 

Online CatalinaWOW

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Re: USA Cal Club: Round 2
« Reply #738 on: July 07, 2021, 12:20:07 am »
I think there is merit in the I'm ready idea, but needs some more thought on implementation.  Not that what has been proposed so far wouldn't work, but maybe we can come up with something even better.

Here is one possibility.  Use the ordered list but give the next half dozen people on the list a day (or some other fixed, short time) to respond to the I'm ready message with proof.  Kit goes next to the person closest to the front of the list to respond.  List order would be unchanged other than moving the selected party to the next round list.

If the kit moves as fast as I would hope it does this could be modified by allowing the I'm ready proof to be valid for a month or two.  This would avoid people having to generate repeated proof runs.  Other modifications might apply to those with better equipment (calibrated, 8 digit, traceable standards or whatever we feel would be appropriate).
 
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Offline bitseeker

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Re: USA Cal Club: Round 2
« Reply #739 on: July 07, 2021, 07:58:46 pm »
Good ideas. Wouldn't want the process to become cumbersome.

Well, the best way to find out if it works is to give it shot and refine any rough spots.
TEA is the way.
 

Offline rhb

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Re: USA Cal Club: Round 2
« Reply #740 on: July 14, 2021, 02:20:03 am »
I would like to endorse the "I'm ready." concept.  A $3-5 ebay reference would be sufficient to let someone get things set up.  I was quite stressed trying to do a reasonable test run  and get it back out the door.  I'd never done this before and didn't grasp how much work it entailed.

Even though I have done it once already, I'd set up and do a trial run before getting the package the next time.

Have Fun!
Reg
 


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