Hi. I've got a peculiar issue. When the CurrentRanger is in Bias mode, the measurement shown on the OLED is incorrect once it goes above about 70. At that point, the OLED stays near 70 (anywhere between about 65 and 75 with some fluctuation). It shows this regardless of what range is selected (they all show about 70 if the actual value is above that). If I measure it manually on the Raw Out using a DMM, it has the correct value. Please see attached pic showing the discrepancy between what is shown on the OLED vs the DMM. I've tried this on 3 different CurrentRanger units (all shipped in the last few months), and the behavior is consistent. The CurrentRanger is powered from a LiPo battery and no USB is connected. This occurs whether the test circuit is powered from a battery or from a DC supply. Test circuit supply voltage is 3.3VDC. If I disable bias mode it seems to work as expected (for positive voltage).
The reason I am operating in bias mode with a DC source is because there are capacitors on the test circuit and the current could be both positive or negative depending on whether the source voltage is higher or lower than the state of charge on the capacitors.
Have I found an issue or am I doing something wrong?
Thank you.