Tempco of 3458A can be limited pretty much to one of 40K resistor, if you add code into logging script to run ACAL DCV&OHM on each 1C of TEMP? change. That to be expected <1ppm/K.
What is printed is one thing, but it's interesting to see actual curve and it's slopes. It may or may not match the "typical" specs.
We need to get back on topic. Can this device be used as a roving standard for a forum calibration club?
Hi calmachine. Please tell us more. Where do you live/work?
Hi calmachine. Please tell us more. Where do you live/work?
Hey Enut11!! My name is Ryan and I work at ENI Labs in Ft. Wayne, Indiana! Fully 17025 Accredited lab for most everything in the Metrology world! I, myself, specialize in electronic calibrations and specifically 8.5 digit/dc/low freq. Ever since I joined the Lab I've been pushing for better quality practices, procedures, and we are really have been investing a lot in upgrading our standards.
If anyone has any questions, please feel free to ask
www.ENILabs.com
https://www.a2la.org/scopepdf/2147-01.pdf
Hi calmachine. Please tell us more. Where do you live/work?
Hey Enut11!! My name is Ryan and I work at ENI Labs in Ft. Wayne, Indiana! Fully 17025 Accredited lab for most everything in the Metrology world! I, myself, specialize in electronic calibrations and specifically 8.5 digit/dc/low freq. Ever since I joined the Lab I've been pushing for better quality practices, procedures, and we are really have been investing a lot in upgrading our standards.
If anyone has any questions, please feel free to ask
www.ENILabs.com
https://www.a2la.org/scopepdf/2147-01.pdf
What does it feel like to be paid to be a volt-nut?
We've been making some big purchases to drastically increase our uncertainties and I am over here having the time of my life! I'm pretty sure we're going to be snagging 1 of those Datron 4910s posted in the other thread.
I plan on having a Quantum Hall Resistance system up and going by the middle of 2018. And probably a Josephson Array shortly afterwards. I'm so ecstatic for the future
We've been making some big purchases to drastically increase our uncertainties and I am over here having the time of my life! I'm pretty sure we're going to be snagging 1 of those Datron 4910s posted in the other thread.
I plan on having a Quantum Hall Resistance system up and going by the middle of 2018. And probably a Josephson Array shortly afterwards. I'm so ecstatic for the future
For sure you're ecstatic, I see.. But anyhow, you want for sure to decrease your uncertainty, aren't you?
And obviously, you want to found another National Institute of Metrology.. I did not know yet, that any private company owns a QHR system, as it's yet more bulky and pricey than a JJA system, that huge dewar can and that strong superconducting many-Tesla-magnet..
Anyhow, if you succeed, especially in the year of 2018, you'd be well prepared for the new Si-2018!
Frank
Commercial JJA systems are offered by hypres in U.S., the other is supracon in Germany.
They cost about 150-200k, a bit cheaper, as you don't need that magnet and big dewar.
The JJA may be produced by NIST or PTB, anyhow.
Hi calmachine. Please tell us more. Where do you live/work?
Hey Enut11!! My name is Ryan and I work at ENI Labs in Ft. Wayne, Indiana! Fully 17025 Accredited lab for most everything in the Metrology world! I, myself, specialize in electronic calibrations and specifically 8.5 digit/dc/low freq. Ever since I joined the Lab I've been pushing for better quality practices, procedures, and we are really have been investing a lot in upgrading our standards.
If anyone has any questions, please feel free to ask
www.ENILabs.com
https://www.a2la.org/scopepdf/2147-01.pdf
Hi calmachine. Please tell us more. Where do you live/work?
Hey Enut11!! My name is Ryan and I work at ENI Labs in Ft. Wayne, Indiana! Fully 17025 Accredited lab for most everything in the Metrology world! I, myself, specialize in electronic calibrations and specifically 8.5 digit/dc/low freq. Ever since I joined the Lab I've been pushing for better quality practices, procedures, and we are really have been investing a lot in upgrading our standards.
If anyone has any questions, please feel free to ask
www.ENILabs.com
https://www.a2la.org/scopepdf/2147-01.pdf
WooHoo, this might be good news for me, I'm in Terre Haute!
Hi calmachine. Please tell us more. Where do you live/work?
Hey Enut11!! My name is Ryan and I work at ENI Labs in Ft. Wayne, Indiana! Fully 17025 Accredited lab for most everything in the Metrology world! I, myself, specialize in electronic calibrations and specifically 8.5 digit/dc/low freq. Ever since I joined the Lab I've been pushing for better quality practices, procedures, and we are really have been investing a lot in upgrading our standards.
If anyone has any questions, please feel free to ask
www.ENILabs.com
https://www.a2la.org/scopepdf/2147-01.pdf
I have yet to look into a JJA system at all yet... do you know a rough ballpark what one of those systems would run?
Quote from: CalMachineI have yet to look into a JJA system at all yet... do you know a rough ballpark what one of those systems would run?
NIST SRI6000 10V PJVS system pricing is listed on their site, 450K for compressor cooled all in one or 320K for LHe system. 10V JJA chip itself is 52.4K, 1V AC JVS - 26.3K .
Do you plan to calibrate DIY SSR/Resistance boxes, like LTZ1000-based/VPG foil 4W modules and such? Perhaps estimated ballpark pricing would benefit many of lurkers here, including myself.
I think specs would be in range <2ppm DCV, <8ppm Ohm (10k) so hopeless voltnuts with 3458 can benefit most, to have small reference box on 6/12 month rotation. You can also have a requirement for inbound SSR to be 0.5ppm stable within 7 days to ensure you not wasting time. So owner would need to do "pre-work" checklist on DUT reference to ensure this.
How about international shipment then? Small box with LTZ modules and resistors can be well below 5kg. Calibration for 1V, 10V, 10k, maybe 1 ohm. Usual procedure, similar to F732B and F742A can be used to make series of measurements over few days after 24h warmup. Such SSR box can have standard F732B ext battery DB9 connector port, to resolve PSU issues.
If you prefer, we can discuss over email details of such, but I think community can benefit a lot from having this info public. I'm not aware of any cal labs doing such service for hobbyists, esp. with international shipping.
At the moment, we don't do long period temperature curves on resistances, which I also want to start providing to our customers
As far as international shipping... I don't see that being much of a problem as long as you, the customer, is willing to pay for international shipping!
TiN, I've not seen any of these LTZ boxes you speak of... they sound pretty sweet! I would love to give them a go... and you say they have a 9pin DSub connector to plug into a F732B?
If you would like to discuss further, either on here or over email, don't hesitate to get ahold of me
QuoteAt the moment, we don't do long period temperature curves on resistances, which I also want to start providing to our customersI more meant that customer himself does "pre-test" before sending the box to you, and you just run it for few days (let box rest day 1, take 10 samples day 2, 10 other samples day 3, send unit back day 4, etc). Not necessary to have 24/7 longterm logging for calibration, you should expect already characterized reference at inbound. It's not the calibration lab job to do testing for the user, when asked (and paid for) only for calibration, which is measurement only, by the books. Hope this clarify things a bit, so we on same page.
QuoteAs far as international shipping... I don't see that being much of a problem as long as you, the customer, is willing to pay for international shipping!They'd better pay . That sounds right, no problems. I just had different experience few years ago, when asked some cal labs to do same thing, with me paying shipping both ways, when I was looking to import DCV/Ohm into my homelab. I hand-carried standards and did own transfers since then, so it's less of an issue for me now, but I'd be looking for 3rd callab cross-check, and your service seem to fit great into the spot.
QuoteTiN, I've not seen any of these LTZ boxes you speak of... they sound pretty sweet! I would love to give them a go... and you say they have a 9pin DSub connector to plug into a F732B?Well, the box I'm talking right now is not that refined, but I see no difficulty to prepare above-mentioned in Q3'2017 timeframe to perform a transfer. Since 2014 I was tinkering and had designed, built and tested compact 7V LTZ1000-based module following standard datasheet application almost exactly, and using bank of 4 modules as my homelab primary DCV standard, doing cross-checks from time to time. Design is fully open-hardware and covered in article on my site. One of latest modules was also tested in more detail covered here and discussed here and even got group of voltnuts to fab PCBs . For my first transfer in March'16 I've used standalone 3458A's A9 module to calibrate my first 3458A after repair. That got me to DCV within 6 ppm, which later in August was improved to <2ppm with bank of 8 x LTZ1000's (6 on my modules, 2 inside K2002's). For Ohms I use aged Vishay hermetic foils so far.
As of power port, it's easy to design in the enclosure to fit my references and provide DB9 interface, which can couple to 732B-7001 battery pack/charger. so you don't have to worry about finding power supply to power up the reference. International shipping is usually too long to have unit sent hot, and shipping large batteries require special permits/legalpapers anyway. So I'll have to test for hysteresis and stability after thermal shock first, before I have anything shipped. Surely other option to have regular mains PSU integrated as well, but that adds weight and size.
QuoteIf you would like to discuss further, either on here or over email, don't hesitate to get ahold of meThanks for being transparent for hobby level things, this is rare thing in metrology market. We can keep discussion here for time being, as things covered are pretty generic. You will get line of voltnuts lineup with their boxes quicker than you realize
Unless one can design JJA which runs at LN2 temps, there is no possibility of 9.5 digit "DMM" smaller than few 42" tall 19" racks and taking few KW of power. Limitation of performance is the reference in most aspects. Conditioned LTZ1000 bank gives you noise/short-term stability in range 0.2-0.4ppm, so even if you pay few M$ to design and make ultralinear ADC you will be limited by this number.
For resistance it's bit better, as you can apply ratiometric measurements with DCCT bridge to get 9.5 digits, but thats still a 42" rack of equipment. Check Measurement International site, they have such system for sale.
JJA-based voltmeter also exists, made by Supracon ?G/PTB.
But even an ADC in the same class as the 3458A would be very interesting. CalMachine how would you like to realize that?