# Non-invasive current sensor noise problem

I'm working on a project where I'm measuring current with a split core CT and feed the signal to an Arduino analog input. The problem I'm facing is that I get noise from nearby systems. Example is when I wire up a small electrical pump (about 250mA), and hold my split core current transformer next to it (without clipping it onto the wire!) I still get readings on the analog input.

This will be a big problem as I'm planning on sensing current at locations where there will be other wires conducting current around. The split core CT I'm using is the SCT-013-005.

Does anyone have any solution for this problem? Is it simply a poor quality current sensor that is not isolated from outside electrical noise? I have not yet tried to measure current with the CT, and have another component nearby drawing current.

On the other hand, when you feed a single wire (that's one turn) through the CT to measure maybe 40 amps peak$^1$ of household consumption, the MMF is 40.
$^1$ this will be different depending what your AC voltage is.