I am trying to build a improvised 4 wire resistance meter with a Digilent Analog Discovery 2 and i am wondering is i am missing anything obvious here or if this approach is terrible.
This is just to learn and experiment, to see if this would be possible and how well it might work.
Basically i have 2 differential ADCs, a programable power supply and 16 digital IO pins that i can program.
My basic idea was to just buy a decent reference resistor on the power supply to get a somewhat stable and and adjustable current source.
And ADC1 goes across my reference resistor, ADC2 across my DUT with proper kelvin probes.
I can measure the current over my reference resistor and the voltage across my DUT.
I found this 100 Ohms ±0.02% ±0.2ppm/°C resistor, bit worried that there is no solder profile in the datasheet but a standard temp profile should not disturb it too much.
https://www.digikey.de/de/products/detail/vpg-foil-resistors/Y1630100R000Q9R/4231501 Already have a bunch or proper resistance meters around to check it against, to make some comparisons how well that works.
Maybe a passive lowpass filter on the ADCs might not be a bad idea with a jumper to see how it impacts the measurements.