So just received my uCurrent, I was very excited to measure how much my battery powered device really consumes in sleep mode. But before that I decided to test it on resistors. Here is my testing setup:
1AA battery half full, happened to be about 1.064V great, makes calculations easier and set of 100k, 1M, 10M resistors.
I created the test circuit and measured the current with my multimeter on uA range. I got expected results.
Then I measured it using the uCurrent on uA range, got about the same results, so far so good.
Then I switched to the nA range and when I measured current through 1M resistor I got about 770 nA, but it should be around 1000nA, when I measured the current through 10M resistor I got about 33nA, should be 100nA which is waaaaaaaay outside the specs.
Is this expected behavior? Did I get a faulty unit? Is my methodology faulty? There was some oily liquid coming from the switches on uCurrent, I'm not talking about flux on the other side of the board, I'm talking about the tiny gaps in the switches, some liquid is oozing from it. Could this interfere with my measurements? Can you advice me how to trouble shoot this?