Hi All Newcomer to the list. Been watching it since I came across it about a month ago. Didn't realise that I wasn't the ONLY person in the world obsessed with having an accurate volt in my back yard for no reason other than that I can.....:-)
This discussion about the Statronics VS4 particularly got my interest. I have one courtesy of fleabay about 4 years ago, for the princely sum of $20 plus delivery (mine was the only bid, which (together with the quad Standard Cell box for about the same) is why I thought I was alone...). The VS4 (and indeed the Standard Cell Box) appears to work very well and all outputs have maintained their relativity over that time within the limits of my measurement patience, even after about a year powered down after I moved house. Plan to start doing some serious tracking real soon now. Each of the 4 independent cells in the VS4 consist of 8 selected, matched and aged LM329s with matched resistors (all off the same reel of Evanohm, selected mica cards, etc), low drift amps etc all contained in a controlled oven. The Statronics stability spec is -2 +-2ppm per year (after year one). The unit was conceived and designed by the CSIRO who run (or at least ran) the Australian National Measurement Laboratory, so I would guess that the spec is conservative. If Will is correct about the Gould 4410/Fluke 732A, these must be pretty good devices. I suspect I won't get one of them for $20! I saw Ben's question about the manual, and Tom's response about the 100 page masters thesis. That would be interesting to read! I have a copy of the Statronics VS4 Instruction Manual Issue 2 which is only about 70 pages, half of which is a treatise on statistical intercomparisons and a HP-85 Basic program. But the first 38 pages contain what I would expect - user instructions, design descriptions, schematics, etc. Unfortunately, I don't have an electronic copy, nor ready access to a scanner. Ben, I note you are in Australia. Whereabouts? I am in Adelaide. Maybe I can get the hard copy to you some way. Roman -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Will Sent: Tuesday, 12 August 2014 5:40 PM To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] Voltage standard spotted for sale, 4410 2014-08-12 1:25 UTC+03.00, Tom Knox <[email protected]>: > I am not sure the use of LM329's was a cost saving measure or > compromise, actually the 4410 uses a different approch, it's basicly is a big oven. > Guildline has been a Metrology leader for decades and has been a > leader including temp measurements and oil baths so I for one would > be interested in how well their approach to a voltage standard performs. The 4410 was not designed or manufactured by Guildline. Just like many of the products sold under their brand name. At the time of design the LTZ1000 was not yet available and the Fluke ref amp was obviously property of Fluke only. The only same level technology available to all manufactueres was the 1N829 zener which if carefully selected and matched can be as good as LTZ1000. Datron calibrators with multiple selected, aged and matched 1N829 zeners are a good example of that. The original 100 page (Statronics) documentation seems to be a masters thesis rather than a product manual and has a detailed description of the design process. The text mentions that the 1N829 temperature compensated zeners were discarded because of the poor availability in Australia where the unit was developed. The LM399/LM329 series was selected because it was the "best available". Band-gap type references were also evaluated but found unsatisfactory at the early stage. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there. _______________________________________________ volt-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.
