real-world voltage reference?

[hendorog]

...should have a proper starting point and document such as MS Excel...

Excel is poor for sharing information as everyone needs to have a copy so you can never tell who has the latest version.

Instead I'd recommend sharing a link to an online document - e.g. google docs spreadsheet.

[Macbeth]

...should have a proper starting point and document such as MS Excel...

Excel is poor for sharing information as everyone needs to have a copy so you can never tell who has the latest version.

Instead I'd recommend sharing a link to an online document - e.g. google docs spreadsheet.

I was about to post the same. Google docs is great for this kind of thing 

[ralphd]

I have 4 unopened packs of 2xAA Energizer Ultimate Lithium. I measured these using my Brymen BM257.

Use-by Date 03-2026
1.826
1.825

Use-by Date 03-2028
1.806
1.810

Use-by Date 03-2028
1.806
1.806

Use-by Date 03-2028
1.805
1.806

Smaller sample, but wider range: 1.815V +- 0.6%.  It's looking like they make for an OK 1% reference.

[ralphd]

Here's a link for the .5% CJ431s going for 136c/100.
www.aliexpress.com/item/Free-shipping100PCS-TL431-TL431A-SOT23-SOT-23-CJ431-431-Precision-Voltage-Source/32409866977.html

They're a bit different than the other 431's in that their typical voltage is 2.5V instead of 2.495V.
http://www.cj-elec.com/txUpfile/20134181414159042.pdf

If they were TO-92 instead of SOT-23 I'd probably order them just so I could compare them to the Wing Shing 431s.

[ralphd]

My point was to see if there is a common household item like a battery that can be used as a voltage reference.
It would be useful to hobbyists that aren't going to spend $10 on a precision reference.
Anyway, I'll probably end up getting a max6126 just to satisfy my curiosity.  And maybe I'll find a common household item that others can use for a 1% reference...

Your meters out of the box specs are orders of magnitude more accurate than any of the sources you're looking at, it is almost impossible that you will adjust the meter to be more accurate using them, and almost certain that you will make it worse.

Where did you pull the specs on my meter from?  Out of your arse?

It's a Mastercraft branded, Colluck-made meter I paid $20 for.
https://www.eevblog.com/forum/testgear/how-bad-can-a-cheap-multimeter-be/

According to this post, it's rated 0.8% + 5 counts for DC volts:
https://www.eevblog.com/forum/testgear/canadian-tire-mastercraft-dmm-new-and-old-revision-teardown/

From the 0.3% TL431s I can tell the meter is at least 0.5% high.  And when the 0.05% REF5050s I ordered come in, I'll be able to narrow that down even more.

[ralphd]

I tested the first 8 batteries from a pack of HomeDepot "defiant" MIC AAA batteries, Dec 2020 exp:
1.610, 1.611, 1.610, 1.611, 1.610, 1.611, 1.610, 1.611

This is after adjusting the calibration of my meter to within 0.1%.

[ralphd]

I tested the first 8 batteries from a pack of HomeDepot "defiant" MIC AAA batteries, Dec 2020 exp:
1.610, 1.611, 1.610, 1.611, 1.610, 1.611, 1.610, 1.611

This is after adjusting the calibration of my meter to within 0.1%.

Just did the math on the (surprising) consistency of the HomeDepot batteries.  1.6105V +- 0.03%.

[Muttley Snickers]

I have 4 unopened packs of 2xAA Energizer Ultimate Lithium. I measured these using my Brymen BM257.

Use-by Date 03-2026
1.826
1.825

Use-by Date 03-2028
1.806
1.810

Use-by Date 03-2028
1.806
1.806

Use-by Date 03-2028
1.805
1.806

The four packets of 4 Energizer Ultimate Lithium that I have purchased are all giving a similar result to what Flenser got with the ones that I have marked in blue, the ones in red and also the samples provided by kwass all indicate a higher reading than I was getting possibly indicating a variance related to batch or date codes, so as a reference I think we are back to square one, the date codes on all mine were 12-2034 and purchased from the same retail outlet within a 10 day period.

And if we are seeking a real world reference then ideally it should be one that is readily available globally.


Muttley