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DIY Precision Reference for DVM Calibration

Started May 3, 2020 | Discussions thread
mawyatt2002
OP mawyatt2002 Contributing Member • Posts: 502
Re: DIY Precision Reference for DVM Calibration

Johannes Zander wrote:

Hi Mike,

thanks for your nice comment.

I am not so scientific. I didn't do an long term drift test. I observed that it drifts between 9.9992 and 9.9995. This is precise enough for me.

I searched a bit about burn in for aging electronic devices and found this forum:

https://www.eevblog.com/forum/metrology/lm399-based-10-v-reference/250/

They talk about paralleling LM399 for reduced noice.

Good look with your research.

Regards

Hi Johannes,

I've observed the LM399 random drift over the past few days, it's now below ~30uv. So seems to be "settling in". The reading is centered around 6.85498 volts at ~1ma. This part may be an "outsider" since the norm is 6.95 volts for the LM399, and thus may not be a good representation of the LM399 (maybe a reject that I got off eBay??).

Thanks for the link. Paralleling devices not only improves low frequency noise but also drift.  If one wanted to create a serious standard voltage reference then paralleling devices seems like a good approach, but the LTZ1000A is a better device for this. These are expensive tho (why I don't have one).

BTW what DVM are you using?

Best,

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Research is like a treasure hunt, you don't know where to look or what you'll find!
~Mike

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