Dear Quarks - I have following extra info (from John):
These are two chip devices.....an S foil, they use in S102 resistors, and a K foil which they use in S102K. These have opposite polarity second order terms, ie the parabolas are inverted. I think that is standard for the VHP101 and VHP102. However, Vishay can also apply a 48 hour 125C unpowered burn-in process - called PMO
Z foil can be very good and is probably better if power is dissipated (which is the case for the 10R) because, to balance the parabolas, different values need to be used in a ratio of about 3:1 (the ratio of of second order term magnitude) and therefore the two chips will dissipate power differently and run at slightly different temperatures under power.
Best regards
Flinstone
ps.: It is correct that VPG also used C foil (K & S) as terminology ...
Hello Flinstone,
I am not sure if we have a simple misunderstanding, because I am with you.
In my reply about the 3 alloy foils (C, K and Z) I think/hope this is still correct (but it is only from memory several years back).
Therefore my suggestion was/is to go for option with Z-Foil (e.g. VHA51x-xZ) if it is available.
About "S-Foil" my understanding was/is, S-Foil is not an alloy foil, but a combination of C-Foil alloy resistors and K-Foil alloy resistors.
If that is wrong it would be great if you can share some more details.
bye
quarks
Box finished. I will measure tempco in +/-10°C if measurable with my test gear.
Anyone interested as travelling standard?
looks good to me, thanks for sharing
If you are willing to send it to Germany I am interested.
Out of curiosity, are you planning to add a temp sensor?
Did you get a calibration certificate from VPG?
You'll be lucky in Antarctica!
I'm interested if you send to Slovenia
Thank you
A little ways down the road (when I am set up for ohm-nutting), I'd be happy to pay to have it shipped to the US!
looks good to me, thanks for sharing
If you are willing to send it to Germany I am interested.
Out of curiosity, are you planning to add a temp sensor?
Did you get a calibration certificate from VPG?
No, I did not asked for it.
Yes, adding Pt100 will be piece of cake
Is there any connector to outside world preferred?
to bad, you did not ask as I think they should have the data anyway
about Pt100, I would go for a 4wire connection with normal binding posts
That should be the easiest way to connect a DMM
to bad, you did not ask as I think they should have the data anyway
about Pt100, I would go for a 4wire connection with normal binding posts
That should be the easiest way to connect a DMM
My idea was to use some mini DIN or some screw socket. I needs to search little bit.
Also found few 10k PWW from Edwin (708 type).
Another box with Edwin PWW is made and can be shipped with VHA518 box.
My idea was to use some mini DIN or some screw socket. I needs to search little bit.
Also found few 10k PWW from Edwin (708 type).
Another box with Edwin PWW is made and can be shipped with VHA518 box.
You can choose any connector you prefer, but then you have to have a mating connecting cable for your DMM.
That is why I would use easy to connect binding posts in my own design.
About WW resistors, if you use a single resistor I do not think you can get as good as your VHA.
Most likely you would need to match two with opposite canceling TCR.
Hello,
I´m also interested in germany (like the user quarks, maybe after him), if you are willing to send to our country.
Box finished. I will measure tempco in +/-10°C if measurable with my test gear.
Anyone interested as travelling standard?
Virtually no TCR at all in all virtually bought resistors.
Box finished. I will measure tempco in +/-10°C if measurable with my test gear.
Anyone interested as travelling standard?
Am I a bit late for shipping to Canada? I would like to try measuring it with my Advantest R6581T.
...
Did you get a calibration certificate from VPG?
I have decided to purchase a 4-wire lead 10 kΩ resistor Y473310K0000S0L (VHA518-11Z) with post-manufacturing operations (PMO) from Vishay Precision Group to act as a transfer standard for my Advantest R6581T 8.5-digit multimeter. My plan is to mount the resistor in a shielded box and crimp LowThermal ring terminals onto the leads so that I can fasten them to 2758 Series LowThermal binding posts. This should avoid any potential soldering damage and allow simple disassembly if required in the future. If anyone is interested, I have attached Technical Note 103 on soldering foil resistors. The applications engineer provided me with some additional options (there are likely more, but some might be exclusive to manufacturers and other more valuable customers):
- perform a
resistance check and record with each resistor and send the data to me OR Vishay can supply a
NIST certification 
- Vishay can also supply a non-standard lead at 80 mm [3.15 in] length instead of 25.4 mm with optional sheathing (I am merely informing members and do not intend to go with these options)
My assumption is that the VHA518 resistor will experience the most amount of change during the first year. This is why PMO is desirable for my resistance standard application. According to the Field Design Engineer, the procedure for PMO is custom and based on the clients' design intention. They did not elaborate on their techniques, but they said that they would focus on stability in order to ensure performance via a
minor PMO for this single resistor purchase. Would it be practical to choose the NIST certificate option that likely costs significantly more, or should I go with the simple 'resistance check with record' option and have the resistor checked again in a year's time by a calibration lab? In practice, the minor PMO should remove much of the initial drifting, but I do not have enough information to quantify the effectiveness of this optional step. My guess is that I am overthinking things and I should simply be grateful for their 'check with record' offer. What do you think?
Regards.
Do they allow anyone to order 1 single piece, or it's just you? Did they told you how much would cost PMO, and measurement? It seems an easy way to get your own standard.
Do they allow anyone to order 1 single piece, or it's just you? Did they told you how much would cost PMO, and measurement? It seems an easy way to get your own standard.
They seem to be prepared to quote single-unit orders. I am still in the process of the request, but they should email me soon about the price. The HZ Series is intended for metrology, so yes.
I will be ordering a resistor from AVNET.com with a custom part number provided by Vishay. The base cost is 315.33 USD and there is a 16 week factory lead time. I assume it will be more expensive with the PMO option and take longer to prepare as a result. If you aren't in an immediate hurry for a secondary standard, this is a good option.
...
The applications engineer provided me with some additional options (there are likely more, but some might be exclusive to manufacturers and other more valuable customers):
- perform a resistance check and record with each resistor and send the data to me OR Vishay can supply a NIST certification
- Vishay can also supply a non-standard lead at 80 mm [3.15 in] length instead of 25.4 mm with optional sheathing (I am merely informing members and do not intend to go with these options)
...
"The RC check would add about a 1 USD per unit and the NIST would be a 40 USD minimum and would increase after 15 units" -- Vishay Applications Engineer
For 40 USD per unit, a NIST calibration is an absolute deal!
My local calibration laboratory would charge considerably higher to perform the same service.
It's kind of a joke to me that it is cheaper just to buy a calibrated secondary transfer standard set (10 DCV Zener buffer reference and 10 kΩ).
Do they allow anyone to order 1 single piece, or it's just you?
The minimum order quantity (MOQ) is 1. I do not think I am in any way being given special preference.
...
The base cost is 315.33 USD and there is a 16 week factory lead time. I assume it will be more expensive with the PMO option and take longer to prepare as a result. If you aren't in an immediate hurry for a secondary standard, this is a good option.
With the stability/resistivity PMO option and a NIST calibration (40 USD), the resistor was quoted at 503.62 USD to date. The shipping estimate is given as November 19th, 2021 (23 week factory lead time). Luckily, I have a few other Vishay VHP100 Series resistors which will keep me occupied for the time being. I am going to go ahead with the purchase. The distributor I was assigned by Vishay was ELcoPC who is situated in Pennsylvania state.
Now there is plenty of time to design the enclosure!
Leigh,
Just curious do you know that Texas Components sells metrologycalibration standard resistors? Seems like a good deal given what you are going through? Or not.
http://webdirect.texascomponents.com/SearchResults.asp?Cat=1839
I am new to this realm of engineering and am not aware of this company. Thank you for bringing this company to my attention. The specifications are certainly tempting. Are banana plugs an option for 8.5-digit DMM calibrations?
Leigh,
Just curious do you know that Texas Components sells metrologycalibration standard resistors? Seems like a good deal given what you are going through? Or not.
http://webdirect.texascomponents.com/SearchResults.asp?Cat=1839
I am new to this realm of engineering and am not aware of this company. Thank you for bringing this company to my attention. The specifications are certainly tempting. Are banana plugs an option for 8.5-digit DMM calibrations?
I have not used that TXSFR standard myself, but it looks like it directly plugs into your (and my!) 6581T for cal purposes. I believe the same spacing is also useful for a 3458a. It is a nice feature of the 6581 and 3458a that they allow this type of calibration.
If the meter calibration requires leads I guess the company sells an adapter of some sort (or you can make one).