[volt-nuts] Matched resistors

[Frank Stellmach]

Randy,

resistor matched in T.C. are extremely expensive, as the manufacturer 
(or yourself) would have to select these from a batch of many samples.

reistors with very small T.C. (<1ppm/K) would do the job also, but they 
also need to be stable over time, in shelf life opereation mode, i.e. 
P<10mW.

That means, you need those hermetically sealed VHP202Z from Vishay, T.C. 
is typically < 1ppm/K and they are stable to < 2ppm over 5years. But 
they cost already 80€ each, depending on tolerance.

I made a longterm observation of these and found these parameters confirmed.

Frank