Voltage Reference - Page 1
Forum section: electronics / beginners

author: Rafael
author_rank: Regular Contributor
timestamp: March 10, 2018, 06:23:10 pm
content: Hello Voltnuts...Please, I got a 10V Voltage Reference Standard from eBay where the promise is+-2ppm.The seller guarantees that he is calibrated and is only blaming the humidity of the environment.Thanks a lot.

author: TiN
author_rank: Super Contributor
timestamp: March 10, 2018, 06:53:58 pm
content: Seller cannot guarantee you promised spec on that little box (have a read if you bored and have good sense of humor), but also you need keep both meters in high-impedance mode and 8846A might cause errors when connected together with other meter. You may want to have both meters connected one at a time. And anyway calibration performance even for freshly calibrated 34401 and 8846A is far worse than 2ppm.Nixie temp meter is slick.

author: glarsson
author_rank: Frequent Contributor
timestamp: March 10, 2018, 06:57:44 pm
content: Quote from: Rafael on March 10, 2018, 06:23:10 pmDid the seller promise an absolute accuracy of 2ppm, a drift per day/month/year of 2ppm or a drift of 2ppm per kelvin temperature change?

author: IanB
author_rank: Super Contributor
timestamp: March 10, 2018, 07:05:01 pm
content: There's no way a little black plastic box from eBay is going to match the performance of those expensive multimeters. I'd say the reading you are getting is not bad, considering...

author: TiN
author_rank: Super Contributor
timestamp: March 10, 2018, 07:13:26 pm
content: Sorry, read the user manuals. They have good Info's. Its 3am here now

author: 2N3055
author_rank: Super Contributor
timestamp: March 10, 2018, 11:29:02 pm
content: There are few threads "dedicated" to this scam... for instance :https://www.eevblog.com/forum/metrology/calibratory-d-105-dc-precision-voltage-reference-standard/I'm afraid you got "kaysered"... You should have bought on of "those small boxes of reference of china AD584H"... They would be comparable in specs and much much cheaper...Also,http://www.voltagestandard.com/-.html] http://www.voltagestandard.com/-.html actually works as specified.... For much less money...

author: MasterT
author_rank: Frequent Contributor
timestamp: March 11, 2018, 01:22:45 am
content: I wander, if X-ray screening at the custom /inspection station could be blamed. My google search on topic brings this doc :https://www.intersil.com/content/dam/Intersil/documents/an15/an1533.pdfDoes such issue exist with all highly priced metrology equipment, and how it could be avoided?

author: Gyro
author_rank: Super Contributor
timestamp: March 11, 2018, 10:24:21 am
content: No, those Intersil references use charges stored on floating gate FETs as their reference. Very easy to produce custom voltages but very sensitive to Ionizing radiation, x-rays etc which drains the charge away - just like UV EPROMS.It's a very different mechanism to other references, to change the voltage of a buried zener would require very large amounts of radiation to damage the atomic structure of their junctions.EDIT: The problem with the OP's reference probablyishumidity - if you check back through the referenced threads about it, it uses an Epoxy packaged REF02 rather than hermetic, making it very humidity sensitive (at the level of precision involved). The claims about its accuracy took no account of that (though a few weasel words have now been added to the listing).