Let's say I wanted to create a reference resistor and I have access to plenty of 1k 0.1% 25ppm resistors.
I realise that the math says the tolerance will remain the same no matter how I connect them (since they may all be 0.1% high, for example).
But if they are assumed to have a value which is normally distributed around the nominal value, will the frequency distribution change (i.e. the likelihood of a value closer to nominal will rise)?
I am contemplating building a reference resistor from 100 0.1% resistors and I am hoping for a value that is well within 0.1% of the nominal value. The resistors are 25ppm/degC, so that's a 0.0025% variation per degreeC. Should I place the reference in an oven to maintain a constant temperature? -- this may be going over the top (Or perhaps not. -- 20C change is 0.05% which is 1/2 of the resistor tolerance)
I realise that the math says the tolerance will remain the same no matter how I connect them (since they may all be 0.1% high, for example).
But if they are assumed to have a value which is normally distributed around the nominal value, will the frequency distribution change (i.e. the likelihood of a value closer to nominal will rise)?
I am contemplating building a reference resistor from 100 0.1% resistors and I am hoping for a value that is well within 0.1% of the nominal value. The resistors are 25ppm/degC, so that's a 0.0025% variation per degreeC. Should I place the reference in an oven to maintain a constant temperature? -- this may be going over the top (Or perhaps not. -- 20C change is 0.05% which is 1/2 of the resistor tolerance)