[volt-nuts] volt-nuts Digest, Vol 96, Issue 15

[new]

Ever wonder why they have  FOUR 732b units in a 734?

(smile) You need at least 3 of anything unknown. 4 is better.


On 8/31/2017 12:00 PM, volt-nuts-request at febo.com wrote:
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> Today's Topics:
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>     1. 732A drift (Alan Ambrose)
>     2. Re: 732A drift (Andre)
>     3. Re: 732A drift (m k)
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> ----------------------------------------------------------------------
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> Message: 1
> Date: Wed, 30 Aug 2017 16:33:55 +0000
> From: Alan Ambrose <alan.ambrose at anagram.net>
> To: "volt-nuts at febo.com" <volt-nuts at febo.com>
> Subject: [volt-nuts] 732A drift
> Message-ID: <F18848E7-C3D6-4375-9F82-F7C6CEA2FB8F at anagram.net>
> Content-Type: text/plain; charset="utf-8"
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>>>> My 732A<x-apple-data-detectors://28> e.g. has a drift of only about 0.2ppm pa over a couple of year
> Hope you don't mind me jumping on this thread and asking a basic question: is there any kind of procedure for the 'enthusiast' (say with single 3458A/single 732 and not say 4x732) to measure the drift of a particular 732.
>
> Alan
>
> ------------------------------
>
> Message: 2
> Date: Thu, 31 Aug 2017 05:15:18 +0000
> From: Andre <Andre at Lanoe.net>
> To: Discussion of precise voltage measurement <volt-nuts at febo.com>
> Subject: Re: [volt-nuts] 732A drift
> Message-ID: <1504156517622.25651 at Lanoe.net>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Hi, first post!
> Yeah, I ran into this issue a while back. Fortunately for most applications 10mV resolution is fine (eg measuring charge state on Li-ion cells) but I did find that old meters do seem to experience random drift failures of precision resistors and more so trimpots. Would it be a good idea for someone to do a "732 FAQ" with likely faults that would cause a particular matrix of symptoms?
>
> Also how do you deal with failures where a precision component has "gone bad" ? Surely all the calibrations are suspect which is why any sensible engineer always has two references at a bare minimum and sets up a master/slave or main/backup then maintains a calibration table of each? so if a drift is seen then the "bad" unit can be dealt with sternly.
>
> I looked into making a 10.0000Vref a while back and had some success with active feedback via thermal pad: it almost worked but in the end it was cheaper and simpler to buy one ready made (cough REF02 /cough)
> Also relevant, since originally buying my RS IDM65 you can now get I2C precision CT references which can replace the troublesome parts
> with something that does not drift, ever!
>
> -Andre
>
>
> ________________________________________
> From: volt-nuts <volt-nuts-bounces at febo.com> on behalf of Alan Ambrose <alan.ambrose at anagram.net>
> Sent: 30 August 2017 17:33
> To: volt-nuts at febo.com
> Subject: [volt-nuts] 732A drift
>
>>>> My 732A<x-apple-data-detectors://28> e.g. has a drift of only about 0.2ppm pa over a couple of year
> Hope you don't mind me jumping on this thread and asking a basic question: is there any kind of procedure for the 'enthusiast' (say with single 3458A/single 732 and not say 4x732) to measure the drift of a particular 732.
>
> Alan
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> ------------------------------
>
> Message: 3
> Date: Wed, 30 Aug 2017 20:12:46 +0000
> From: m k <m1k3k1 at hotmail.com>
> To: Discussion of precise voltage measurement <volt-nuts at febo.com>
> Subject: Re: [volt-nuts] 732A drift
> Message-ID:
> 	<HE1PR0301MB2283CFEF8B3D344A07BAA9FE919C0 at HE1PR0301MB2283.eurprd03.prod.outlook.com>
> 	
> Content-Type: text/plain; charset="utf-8"
>
> On 30/08/2017 17:33, Alan Ambrose wrote:
>>>>> My 732A<x-apple-data-detectors://28> e.g. has a drift of only about 0.2ppm pa over a couple of year
>> Hope you don't mind me jumping on this thread and asking a basic question: is there any kind of procedure for the 'enthusiast' (say with single 3458A/single 732 and not say 4x732) to measure the drift of a particular 732.
>>
>> Alan
>> _______________________________________________
>> volt-nuts mailing list -- volt-nuts at febo.com
>> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts
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>>
> Not really, you have a Voltmeter and a 732b, they drift a little, how do you know which one is drifting, and by how
> much? you cant know unless you have at least one other unit to compare with, then you can build a matrix of all the
> relative drifts and then guess which one is actually the most accurate...
>
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> End of volt-nuts Digest, Vol 96, Issue 15
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