I have got a design for milliohm measurement circuit that I have found on YouTube.
Also avaliable in pdf format.
This design uses the INA106U diff amplifiers and I want to replace it with something else less expensive.
I have found a wide range of diff amps. and also a wide range of instrumentation amps, I want to know which is better for this specific application and why?
Also I want to know what is the most important parameter\s that I should look for when choosing the amplifier, like for example should the Input bias current be as low as possible or should it be the offset voltage or maybe the input/output noise I really not sure about those params.
I want to be able to measure down to 1 milliohm with 0.5 milliohm max. error margin. Also, ambient temperature will be fixed and around room temperature(25C).
For the measurement range from 0 ohm up to 10 ohm, For the resistors that I will be using it will be 0.1% and around 25 ppm, For the stability I will zero the instrument every time I use it so I suppose this a short term stability. And lastly, for the power supply, I will go for whatever the components in my hands will require!