Hi I am taking sweeps of a 100k Ohm resistor paralleled with a 0.1uF capacitor, from 1Hz to 400Hz at 2 V p-p, PGA x1.

When the measurement comes back it does not resemble the matematical model of how the impedance should be changing with frequency. I have attached an origin graph of this behavior and I would be very happy if someone could shed some light on why my maths does not add up.

Regards,

Ronan

Here is an updated and viewable graphic