Matching resistors to 1% or Better

[kopite]

What is the best way to do this? I'm starting to build the Red light amp.

[Stocker]

The easiest way is to purchase resistors with low tolerance

The next easiest is with a high-resolution ohmmeter

Lacking that, a current measurement setup with a low voltage supply...

[AKN]

If it's low ohm resistors compaired to input resistanse of a voltage meter maybe this can be a solution:
how to measure and match source resistors 0,22-1ohm?

[HFGuy]

Just buy them. High tolerance resistors are common place these days with it not being uncommon to see 0.1% resistors. But ask yourself first how much tolerance do i really need ? 1% is more then accurate for most applications. Only time you really need uber high tolerance in resistors is for DACs and those are laser etched.

[jackinnj]

Wheatstone Bridge

[Brian Beck]

I agree with HFGuy. Just buy them. 1% metal film resistors have gotten so cheap and common these days that there's hardly any reason to buy any other kind of low power resistor. Some people swear by (or at) carbon comp resistors for grid stoppers. But I have used films successfully there too. For power resistors, precision wirewound resistors become the best choice, but the price grows.