Hello, I am trying to built a circuit that will have very low current in it something in the micro-amp, even nano-amp if possible. I know the voltage across the resistors so by using ohms law I can get current. I wanted to know if I should be looking for any specific resistor. I know about the tolerance, power rating and thermal coefficient (power and heat shouldn't be a problem at such low currents, right?) I was wondering if there is any other specification that I should look at or if there are any specific resistors designed for this. The largest resistor that I want to have is 1GΩ, and go down a decade until 1kΩ. Thanks!