following your useful guides I made my electricity monitoring system with an Arduino, which has been working well for over a year
Now, if I find some time, I would like to improve the system a bit, by remaking the interface board, for example by implementing the “Buffered Voltage Bias” circuit.
In addition to this I have seen that someone add two 1n4148 protection diodes to the analog inputs, as in this example: Sharing the 2.5V reference, however according to some opinions they should be useless because Vf of the external diodes is likely to be higher than the internal Arduino diodes, which therefore would begin to conduct anyway sooner.
What could happen in my case is that the Arduino is switched off (temporarily) with connected measuring probes: what can I put as protection? I read on some forums to insert a resistance of 10k in series with the signal that applies to the analog pin, but does this not distort the measurement?
thanks for the help