[volt-nuts] Precision resistors

[John Devereux]

Hi Tony

Absolute Calibration in the UK charged 144UKP+VAT to measure a SR104. This
included pickup and dropoff using their own vehicle!

Their stated capability is to +/- 0.24ppm

Very happy with them so far, they can also do zener measurements, e.g 10V to
within 0.23ppm, for similar price.

John


Tony Holt <vnuts at toneh.demon.co.uk> writes:


[...]

>
> Does anyone know how much it would cost to get a 10k resistor measured
> to < 2ppm in the UK by a calibration company? 

>Does anyone know how
> much it would cost to buy a 1% Vishay VH102Z/VHP101 or similar with a
> < 2ppm measurement?
>
> Edwin Pettis quoted me $7.28 for one 10k resistor ($5.46 for 11 to 24)
> so they could be a viable way of getting accurately (approx 1ppm)
> measured resistors. The higher TCR, 3ppm/C would increase the
> uncertainties though as it would require them to be used within 1C or
> so of that when measured by Mr Pettis, but he can select for 1ppm TCR
> or less for an extra $2 which would easily be justified for this
> purpose. Obviously the uncertainties due to transport shocks/vibration
> (although Mr Pettis claims they are very rugged) and drift related to
> the time in transport would need to be considered.
>
>>> On Aug 11, 2015, at 9:00 AM, volt-nuts-request at febo.com wrote:
>>>
>>> Edwin Pettis states his resistors drift is typically better than 2ppm in
>>> the first year, so pretty good but you'd still need to have them
>>> measured every few years. If you have to get them professionally
>>> calibrated it may be cheaper to buy the Vishay parts. Edwin could
>>> provide the measured values as could Vishay if you bought directly from
>>> them.
>> _______________________________________________

-- 

John Devereux