Resistor size / cross section versus low current any effects ?

[Overspeed]

Hello

I am in process to built a set of low values resistor in the 0.001 Ohm range

My 0.001 lab reference is able to handle more than 30 amp ( 50 max ) and inside the box that a thick foil of I suppose in manganin  , I have another one 0.003 which have that same design except the big foil is flat as in a Vishay foil resistor

I have also Vishay shunt 4 wires as WSLP4026 size shunt so far smaller in size rated to 3 W

My question base on the fact the raw material is different so resistivity is different = OK , but does the cross section of resistor and the mass of the resistor have or will have an effect on low current measurement

I measure DC and 70Hz AC voltage in the range between 10 ma and 50mA

As I will run calibration accuracy as true value '' 0.000X0000 '' is not a concern I can work with real measured values during calibration

My goal is to built a setup ( resistor box ) to measure the resistivity of metal and I want to built a reference but I prefer check before as feed a '' big resistor size '' with only 10 mA looks strange compare to 30 Amp and more resistor and I dont locate any articles ob this particular subject

Regards
OS

[Overspeed]

Hello

I have now a far better understanding of resistor technologies and physic after to have read this book

Regards
OS

[branadic]

There is a copy available on xdevs.

-branadic-