Electronics > Beginners

1V Reference @ 1ppm

<< < (5/13) > >>

ArthurDent:
I appreciate the irony that someone asking about precision voltage has a tag line of "LTZ1000 for voltages"

Rafael:

--- Quote from: tggzzz on January 26, 2019, 10:17:23 pm ---
--- Quote from: Rafael on January 26, 2019, 12:22:53 am ---Hello,

Does anyone have any suggestions on how to find / build a 1v @ 1ppm reference?

Thanks a lot!

--- End quote ---

There is a lot of information in other threads on this forum, in the metrology sub forum.

Voltnuttery is expensive, very expensive.

But your question is easy to answer - but is it the right question? Hint: state your problem, not your presumed solution. For reasons, see https://entertaininghacks.wordpress.com/library-2/good-questions-pique-our-interest-and-dont-waste-our-time-2/

--- End quote ---

Thanks a lot for all answers... As a beginner, I need to learn a lot before try some adventures in Metrology section.

I have an old russian voltmeter https://www.eevblog.com/forum/beginners/31-voltmeter-sch-31-nixie-russian-voltmeter/ and I need to calibrate it with 1v reference.

@ArthurDent, I really really admire the precision that the component can generate, but for 1V, it gets a little further.  :-+ edit: Or maybe the answer? Please, be gentle with me... :(

beanflying:
Nice Nixies :) I hadn't seen the thread hiding away in the Beginners section. I have seen similar ones on evilbay from time to time and occasionally tempted.

Given the instrument you really need a better 1V source than even 1PPM assuming it's own internal reference is at least that stable. Those cheap Chinese references are reasonable to 3.5 and 4.5 digit meters or as a sanity check on whatever you may build is close to the actual 1V but no more. The initial accuracy of the Maxim references and the easy trimming I would have confidence to better than 4.5 digits against another good meter but not to 6.5 digits.

Nothing I have for example is up to 'recalibrating' my Agilent 34401A other than I have a pair of 34970A dataloggers with 6.5 digit multimeter cards fitted that are near the same spec. All of my references held at a static temperature give me a reasonable level of certainty as to how the 34401A is behaving over time and temperature but as it is currently out of Cal it really needs to take a trip to a lab or I need to scrape the $ together for a 3458A and keep that in Cal to keep the rest in line ;)

What should be important to you is that YOU are happy you have the required level of precision, accuracy and certainty YOU need unless you go to the cost of getting the meter calibrated at a known Lab. Pick a day or conditions at a known temperature and record it preferably 20-25C. Then raise or lower just the meter if possible and see how the drift is with temperature while the reference hopefully remains at a static temperature. Also watch your connections to the meter you will get several PPM of error with a bad connection. The Russians use an oddball size under 4mm :palm:

Should you build a reference YES but bear in mind what that reference will give you. The Max will get you about as good as you can get for initial accuracy without breaking the bank. To go to an LM399 or LTZ gives you more ultimate stability but a wider range of initial accuracies so if you don't trust the meter a worse result  >:D

tggzzz:

--- Quote from: Rafael on January 27, 2019, 03:17:20 am ---
--- Quote from: tggzzz on January 26, 2019, 10:17:23 pm ---
--- Quote from: Rafael on January 26, 2019, 12:22:53 am ---Hello,

Does anyone have any suggestions on how to find / build a 1v @ 1ppm reference?

Thanks a lot!

--- End quote ---

There is a lot of information in other threads on this forum, in the metrology sub forum.

Voltnuttery is expensive, very expensive.

But your question is easy to answer - but is it the right question? Hint: state your problem, not your presumed solution. For reasons, see https://entertaininghacks.wordpress.com/library-2/good-questions-pique-our-interest-and-dont-waste-our-time-2/

--- End quote ---

Thanks a lot for all answers... As a beginner, I need to learn a lot before try some adventures in Metrology section.

--- End quote ---

If you follow the points in that reference, you will find that most people on most forums will be friendly. A small proportion might not, but that's people for you.


--- Quote ---I have an old russian voltmeter https://www.eevblog.com/forum/beginners/31-voltmeter-sch-31-nixie-russian-voltmeter/ and I need to calibrate it with 1v reference.

--- End quote ---

You probably want to calibrate each range separately; a stable known voltage and a 7 decade Kelvin-Varley Divider is a good starting point. You will realise there is no end point in voltnuttery, only an acceptable level of dissatisfaction :)

You might like to do some initial experiments.

For example find a battery which is reasonably stable, keeps its temperature reasonably constant, connect it to your meter, turn on the meter, and record the measured value until it becomes stable. Some meters (particularly old ones) take quite a few hours to stabilise. Keep an eye out for popcorn noise in the meter's reference, and variations with temperature.

When at the uV levels, seebeck/thermocouple effects become noticeable.

iMo:
The answer is simple: there is not such an 1V/1ppm source available in form you would expect (not talking volnuttery capable calibrators). As I can see on the pictures from your link you are already volnut-positive, so you are asking in a wrong section :)

Navigation

[0] Message Index

[#] Next page

[*] Previous page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod