Hey guys, so the other day I had a course about capacitive sensors and this thing below came up. The capacitive sensor is connected to the conditioner via two coaxial cables, the outer conductor of those cables are conected to a metallic casing which is also conected to physical ground. The parasitic capacitance is supposed to be really small when connected in this arrangement. The point of connecting to physical ground is having a different potential from the one of circuit´s ground. I asked my teacher why would we need to connect the casing to physical ground and he explained it to me but at the end I didn't understand. I remember doing tests at the lab with capacitors. Whenever we needed to get rid of the charge in a capacitor we would just touch both of its terminals with a resistor in our hand. I heard charges in the capacitor were attracted to ground because we were standing in it. I also read that negative charges would be attracted to physical ground because of the abbundance of positive ones in it. As Capacitance equals Charge over voltage I thought parasitic cappacitances would reduce if accumulated charges were taken away from our parasitic capacitor. However, I'm not sure about any of that. If you shed some light on this I will really appreciate it.