Want: 0.01% Resistors

[Wh1sper]

For the purpose of self calibrating my Philips 2534 I'm searching for 30R, 300R, 3K, 30K, 300K and 3M Ohms 0.01%
I've found some for 14€ Euro each which is a way to high for me.
Has anybody an idea where I can find those?
I've hope that 3-5€  should be enaugh for one.

Whenever you can offer only a few of them I'm strongly interested.

Regards

[Kjelt]

Why not make them yourself if it is for occasional calibration only? Ofcourse you need access to a calibrated meter.

[Wh1sper]

Thats the point....
None, I mean absolutly nobody in my realm be it physically our in the term of frienship has one.
 

[max-bit]

http://www.ebay.pl/itm/VISHAY-0-01-VSRJ-RS92N-Metal-Foil-Resistance-Resistor-100-200-5K-10K-Ohms-/291125244302?pt=FR_YO_MaisonJardin_Bricolage_ElectroniqueComposants&var=&hash=item43c86ab18e

[jpb]

You can build accurate 10:1 dividers yourself using the 3 matched Rs in parallel and matched to another Rb then the the three Rs in series is 9 times Rb so Rb is 1/10 the total resistance.

This means you might get away with one expensive 0.01% resistor, a 10:1 divider then use it to make the other ones yourself (using trimmers).

You can use your meter to do the matching as it doesn't need to be calibrated to match Rs, just give consistent readings (or you could use a bridge circuit).

A further thought, if you matched a second resistor to Rb then you could have a bridge with (3Rs+Rb) in series with the second Rb on one side, the known R (0.01%) in series with the one you're making on the other and trim until balanced. You can thus go from R to R/10 and so on though I guess errors would mount.

To get around the cumulative errors, or at least get a check, you could perhaps get two 0.01% resistors one at each end of the range then you could work in both directions and compare your final home-made with the known good value.

[Wh1sper]

You can build accurate 10:1 dividers yourself using the 3 matched Rs in parallel and matched to another Rb then the the three Rs in series is 9 times Rb so Rb is 1/10 the total resistance.

This means you might get away with one expensive 0.01% resistor, a 10:1 divider then use it to make the other ones yourself (using trimmers).

You can use your meter to do the matching as it doesn't need to be calibrated to match Rs, just give consistent readings (or you could use a bridge circuit).

A further thought, if you matched a second resistor to Rb then you could have a bridge with (3Rs+Rb) in series with the second Rb on one side, the known R (0.01%) in series with the one you're making on the other and trim until balanced. You can thus go from R to R/10 and so on though I guess errors would mount.

To get around the cumulative errors, or at least get a check, you could perhaps get two 0.01% resistors one at each end of the range then you could work in both directions and compare your final home-made with the known good value.

Yes it's the second best option.
These two links are already in my portfolio :-)

http://conradhoffman.com/HamonResistor.html

http://www.gellerlabs.com/752AJunior.htm

[Wh1sper]

http://www.ebay.pl/itm/VISHAY-0-01-VSRJ-RS92N-Metal-Foil-Resistance-Resistor-100-200-5K-10K-Ohms-/291125244302?pt=FR_YO_MaisonJardin_Bricolage_ElectroniqueComposants&var=&hash=item43c86ab18e

Ohh, didn't find it by myself, thanks.

[Dago]

Just buy 0.01% resistors off Digikey or whatever supplier you prefer? Loads of them starting at 1.15€/each from Digikey (only one I checked) at least: http://www.digikey.fi/product-detail/en/RNCF0805TKT20K0/RNCF0805TKT20K0CT-ND/2687088

[mariush]

Farnell has 0.05% resistors for 0.25-0.4 euro a piece. 0.02% are a bit more expensive. 0.01% ohm resistors are indeed 10+ euro. In theory, you can put several 0.05% resistors in parallel to get the percentage better without raping your wallet... ideally, in practice i found most tend to be above or below the resistance value, it's hard to pick 10 for example and be sure the average will be closer to exact value/10 you want.

See

http://de.farnell.com/smd-chip-widerstande
http://de.farnell.com/widerstande-fur-durchsteckmontage

Filter by tolerance you want, exclude extended range/USA import from the left side menu (you don't want to pay bunch of euros to have a few resistors shipped from US to you), then sort by price and ignore the 0 ohm resistors. 

[Wh1sper]

Farnell has 0.05% resistors for 0.25-0.4 euro a piece. 0.02% are a bit more expensive. 0.01% ohm resistors are indeed 10+ euro. In theory, you can put several 0.05% resistors in parallel to get the percentage better without raping your wallet... ideally, in practice i found most tend to be above or below the resistance value, it's hard to pick 10 for example and be sure the average will be closer to exact value/10 you want.

See

http://de.farnell.com/smd-chip-widerstande
http://de.farnell.com/widerstande-fur-durchsteckmontage

Filter by tolerance you want, exclude extended range/USA import from the left side menu (you don't want to pay bunch of euros to have a few resistors shipped from US to you), then sort by price and ignore the 0 ohm resistors.

Hhm follow the second THT link and do as described I've got 1.xx €  but only 250R, not more values,  but thanks your tip I'll do a bit more searching...
Ahh SMD is the key, but they are a bit worse @tempco