[volt-nuts] First post

[Dick Moore]

Hi Bill -- The HP3458A has an AC measurement mode that for frequencies of 50kHz or less does an A-D conversion of sample points then calculates the RMS value, instead of the usual mode of rectifying the signal and the calulating the RMS. The outstanding linearity of the A-D in the 3458 means that it is very accurate, with much lower uncertainty than the 510s, and the cal data for the 3458, which is fairly recent tends to support this. So, I'm using it to look at the 510s outputs. I'm also a bit mystified why setting the 510s internal reference to the recommended 14.142136 VDC doesn't actually result in a 10VAC output; The peak detector-comparator circuit seems to have pretty good performance. I've tried varying the internal adjustments of the 510 one at a time to gauge effects on output level, and the only one that really seems to matter is the reference level setting. Any light youc an shed would be welcome.

Ulrich, thanks for the kind offer. I hope to get into GPIB in the late spring or early summer.

Best,
Dick Moore

> 
> Message: 4
> Date: Wed, 20 Jan 2010 13:50:55 -0800
> From: WB6BNQ <wb6bnq at cox.net>
> Subject: Re: [volt-nuts] First post
> To: Discussion of precise voltage measurement <volt-nuts at febo.com>
> Message-ID: <4B577ABF.992F8E02 at cox.net>
> Content-Type: text/plain; charset=us-ascii
> 
> Hi Dick,
> 
> Out of curiousity how are you determining that the 510's are drifty ?
> 
> Bill....WB6BNQ
> 
> 
> Dick Moore wrote:
> 
>> Hi all. This is my first post to volt-nuts. Glad to find this list; got here from time-nuts. My little lab (on the western shore of Puget Sound) has a couple of Fluke 732A DC Refs, an HP 3458A (no options), a Datron 1082 DMM, a Fluke 5440B Direct Volts Calibrator, a couple of Fluke 510A AC Standards (400Hz and 40kHz), and a variety of resistance standards, other bridges, meters, etc.
>> 
>> I hope to make time to dig around in the archives. For now, I'm interested in any experience you all have with the long-term drift of the Fluke/Motorola reference modules used in the 732s, the 5440 and the 510s (as well as the 850x series of meters). I'm also wondering about the stability of the 510s in particular, which seem very drift prone and highly temperature sensitive -- comments and any practical mods welcome. Has anyone subbed in an LTZ1000A in any of these units?
>> 
>> I hope to begin using a Prologix USB>GPIB converter, yet to be purchased, for data gathering and control, via Ulrich's EasyGPIB
>> 
>> Best,
>> Dick Moore
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> 
> 
> 
> 
> ------------------------------
> 
> Message: 5
> Date: Thu, 21 Jan 2010 09:36:37 +0100
> From: "Ulrich Bangert" <df6jb at ulrich-bangert.de>
> Subject: Re: [volt-nuts] First post
> To: "'Discussion of precise voltage measurement'" <volt-nuts at febo.com>
> Message-ID: <4EE06AF31FB7453686157B8EAB043E73 at athlon>
> Content-Type: text/plain;	charset="us-ascii"
> 
> Dick,
> 
>> I hope to begin using a Prologix USB>GPIB converter, yet to 
>> be purchased, for data gathering and control, via Ulrich's EasyGPIB
> 
> Should you need any assistance, don't hesitate to contact me directly!
> 
> Best regards
> Ulrich
> 
>> -----Ursprungliche Nachricht-----
>> Von: volt-nuts-bounces at febo.com 
>> [mailto:volt-nuts-bounces at febo.com] Im Auftrag von Dick Moore
>> Gesendet: Mittwoch, 20. Januar 2010 22:19
>> An: volt-nuts at febo.com
>> Betreff: [volt-nuts] First post
>> 
>> 
>> Hi all. This is my first post to volt-nuts. Glad to find this 
>> list; got here from time-nuts. My little lab (on the western 
>> shore of Puget Sound) has a couple of Fluke 732A DC Refs, an 
>> HP 3458A (no options), a Datron 1082 DMM, a Fluke 5440B 
>> Direct Volts Calibrator, a couple of Fluke 510A AC Standards 
>> (400Hz and 40kHz), and a variety of resistance standards, 
>> other bridges, meters, etc.
>> 
>> I hope to make time to dig around in the archives. For now, 
>> I'm interested in any experience you all have with the 
>> long-term drift of the Fluke/Motorola reference modules used 
>> in the 732s, the 5440 and the 510s (as well as the 850x 
>> series of meters). I'm also wondering about the stability of 
>> the 510s in particular, which seem very drift prone and 
>> highly temperature sensitive -- comments and any practical 
>> mods welcome. Has anyone subbed in an LTZ1000A in any of these units?
>> 
>> I hope to begin using a Prologix USB>GPIB converter, yet to 
>> be purchased, for data gathering and control, via Ulrich's EasyGPIB
>> 
>> Best,
>> Dick Moore